JPH1195051A - Optical signal processor and optical signal processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain generation of optical pulses of 1-10 ps, waveform shaping, waveform measurement, waveform recording and correlative processing by providing a mirror for reflecting incidence of light focused by a second means for focusing the optical output of a waveguide array. SOLUTION: After entering a quartz wave guide 1, an input optical signal u (t) is diverged into an array 3 of N-number of wave guides by a star coupler 2. The wave guide array 3 is so set as to have optical path length difference ΔL between an incident face S1 and an outgoing face S2 . Frequency resolution is proportional to Nm at the time of using m-order diffracted light, where N is the number of wave guides of the wave guide array 3. Large resolution can therefore be obtained by enlarging (m). A reflecting space filter 5 is installed at a focal plane S3 of such a wave guide array 3 of high resolution, and when the space frequency pattern of the space filter 5 is made H (v), an optical pattern of U (v) H (v) is reflected and goes back through the wave guide array 3 and star coupler 2 so as to be outputted from the quartz wave guide 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for processing, measuring or storing a high-speed optical signal.

[0002]

2. Description of the Related Art FIG. 1 shows an example of a conventional optical signal processing circuit. In this figure, 201 and 205 are diffraction gratings, 20
Reference numeral 2204 denotes a lens, and 203 denotes a spatial filter or an optical storage medium. When the time-series signal light enters the optical circuit, the Fourier transform of the time-series signal light, that is, the frequency spectrum distribution is changed by the spatial filter 20 by the frequency resolution function of the diffraction grating 201 and the Fourier transform function of the lens 202.
3 is formed. When modulation is applied to the frequency spectrum distribution by the spatial filter 203, the waveform of the time-series signal can be modulated. Here, even when the time-series signal is extremely high-speed, the waveform can be controlled by the spatial filter 203.

As an example, a pulse width 2 shown in the upper part of FIG.
When an optical signal of 00fs and a pulse interval of 5ps is incident,
The incident light spectrum has the shape shown in the upper part of FIG.
Spatial filter 2 after passing through diffraction grating 201 and lens 202
3 has the light intensity indicated by the broken line in the middle part of FIG. 3, and when this is modulated by the spatial filter 203, the spectrum after passing through the spatial filter 203 has the shape shown in the lower part of FIG. The time waveform corresponding to this spectrum is a pulse train shown in the lower part of FIG. Thus, by modulating the frequency spectrum of the optical signal with the spatial filter 203, optical signal processing can be performed. That is, various waveform shaping corresponding to the filter can be performed.

[0004] Further, by using the optical storage medium 203 shown in FIG. 1 and simultaneously inputting the time-series signal light and the reference light, interference fringes of both lights are holographically recorded on the optical storage medium 203. After recording, if only the reference light enters, the signal light is reproduced and output. Reports of such studies can be found, for example, in AM Weiner, “Programmable shaping of Femto
second optical pulses by use of 128-Element Liquid
Crystal Phase Modulator, ”IEEE J Quntun Electro
nics, Vol.28, No.4, pp.908-920 (1992): A.Weiner et
al., "Optics Letters, vol. 17, pp. 224-226 (1992).

As the optical communication technology advances, the pulse width of an optical signal used for optical transmission is 100 ps (e) at the stage of practical use.
x; FA-10G system), it is considered that a picosecond pulse of 1-10 ps is used in the next generation ultra-large capacity transmission device. The application of femtosecond light pulses to R & D and material evaluation of stable light sources is an immediate area of application, and is not expected to be applied to optical communications for the time being. In other words, basic devices and methods that enable optical pulse generation, waveform shaping, waveform measurement, waveform recording, correlation processing, and the like of optical pulses of 1 to 10 ps are required to configure a next-generation ultra-large-capacity system. I have.

[0006] However, the above-mentioned prior art has the following problems. That is, whether the above-described modulation or hologram recording is performed, the diffraction grating 201,
It is necessary to arrange all of the lens 205, the lenses 202 and 204, and the spatial filter 203 with high accuracy, and it is easily affected by the external environment and difficult to modularize. near. That is, it is not practical for practical use.

In the case of handling time-series signals, one-dimensional diffraction gratings and lenses can process signals in principle, but the diffraction gratings and lenses have a two-dimensionally redundant structure. Unnecessary alignment is required.

Further, for example, when handling a long pulse train of 10 ps or more or when handling a pulse having a long pulse width, the incident beam diameter is increased and a large diffraction grating or lens is required, so that the apparatus must be increased in size. I can't get it.

That is, in the conventional configuration using a diffraction grating pair and a lens effective for femtosecond pulses, the device becomes extremely large for picosecond pulses, and the size of the transmission device becomes three.
It is difficult to incorporate it into a package of about 0 × 40 × 3 cm. Further, an optical system for connection to an optical fiber is required, and a flexible device design corresponding to a pulse cannot be made.

Conventionally, a semiconductor mode-locked laser is known as a means for generating picosecond pulses.

FIG. 4 shows a configuration of a mode-locked laser used as a conventional short pulse light source.

In FIG. 1, a mode-locked laser includes an optical amplifying medium 51, an excitation circuit 52 for forming a population inversion in the optical amplifying medium 51, and mirrors 53-1, 53 constituting an optical resonator.
-2, an optical modulator 54 disposed in the optical resonator, and a clock generator 55 which is a circuit for driving the optical modulator 54. In this configuration, when the clock generator 55 drives the optical modulator 54 with a clock having a frequency substantially equal to the resonance mode interval of the optical resonator or a frequency that is almost an integral multiple thereof,
An optical short pulse train having a repetition frequency equal to the clock frequency or an integer multiple thereof is generated.

FIG. 5 shows a configuration of a multi-wavelength light source that simultaneously oscillates light of many wavelengths.

In the figure, a multi-wavelength light source is a light amplification medium 6.
1, an arrayed waveguide diffraction grating 62, a lens 63 connecting the optical amplification medium 61 and the arrayed waveguide diffraction grating 62, a high reflection mirror 64 and a low reflection coating 65 disposed on both end surfaces of the optical amplification medium 61, The high-reflection mirror 66 is provided at the other end of the waveguide diffraction grating 62.

The arrayed waveguide diffraction grating 62 is composed of a single input waveguide 71, an arrayed waveguide 73 composed of a plurality of waveguides which are sequentially elongated by a waveguide length difference ΔL, and a plurality of waveguides. An output waveguide 75, a slab waveguide 72 connecting the input waveguide 71 and the array waveguide 73, and a slab waveguide 74 connecting the array waveguide 73 and the output waveguide 75 are formed.

The light incident on the input waveguide 71 is spread by diffraction in the slab waveguide 72, and is incident on each waveguide of the array waveguide 73 arranged perpendicular to the diffraction surface at the same phase and distributed. Light that propagates through each waveguide of the arrayed waveguide 73 and reaches the slab waveguide 74 has a phase difference corresponding to the waveguide length difference ΔL. Since this phase difference differs depending on the wavelength, when an image is formed on the focal plane (the input end of the output waveguide 75) by the lens effect of the slab waveguide 74, an image is formed at a different position for each wavelength. Therefore, the output waveguide 75
Light of different wavelengths is extracted from each waveguide.

In the multi-wavelength light source using such an arrayed waveguide diffraction grating 62, an optical resonator is formed between the high reflection mirror 64 and the high reflection mirror 66, and the optical amplification medium 61 is constantly excited. Thus, light of many wavelengths can be oscillated simultaneously.

The conventional mode-locked laser has the following three problems.

(1) The oscillation mode envelope spectrum fluctuates greatly under operating conditions, and it is difficult to set the center wavelength and pulse width.

(2) Since the intensity and phase for each mode cannot be controlled independently, it is difficult to design a pulse shape.

(3) When a large number of modes are excited, the correlation between the modes becomes insufficient due to the dispersion and nonlinear effect of the semiconductor medium of the long resonator, and a short optical pulse train of the transform limit may be generated. Have difficulty.

Further, in the multi-wavelength light source as shown in FIG. 5, since the phase for each mode is not controlled, it is not possible to lock the mode and generate an optical short pulse train having a high repetition frequency.

As described above, conventionally, a means for generating picosecond pulses includes a semiconductor mode-locked laser.
To be used as a light source for optical communication, the phase and intensity must be stable, the center wavelength, pulse width and pulse shape can be set (designed and manufactured), and high-quality pulses close to the transform limit can be used. It is necessary to generate However, it is difficult for a current semiconductor mode-locked laser to simultaneously satisfy these requirements.
Further, it is extremely difficult to incorporate the conventional technology shown in FIG. 1 into a semiconductor mode-locked light source, and there is no research report.

In an ultrahigh-speed optical transmission device, waveform distortion due to group velocity dispersion in an optical fiber is the first factor that limits the transmission distance. The dispersion characteristic of the transmission line is caused by a change in environmental temperature and a change in the material over time due to a change in coating. This dispersion characteristic also changes when switching to another optical fiber accompanying the switching of the transmission path. Alternatively, even if the dispersion of the optical fiber does not change, the dispersion value perceived by the signal light changes due to the change in the light source wavelength or the filter characteristics.

Even a generally used dispersion-shifted optical fiber having a small dispersion has a dispersion of about ± 1 ps / nm / km, and therefore has a dispersion of ± 80 ps / nm in a transmission section of 80 km. Since the optical band of the signal light having a pulse width of 10 ps at 20 Gbit / s is about 1 nm, a pulse spread of about 80 ps at maximum occurs. However, 20 Gbit / s
Since the time slot of the signal is 50 ps, a large amount of intersymbol interference occurs and a large error occurs. For this reason, a device for compensating (equalizing) the dispersion of the transmission path is indispensable for an ultra-high-speed transmission device.

FIG. 6 shows an example of the prior art. here,
6, reference numeral 01 is an optical amplifier, 02 is an optical switch, 03
Is a dispersion compensating fiber.

The prior art has a configuration in which an optical signal is compensated for dispersion through another optical fiber having a dispersion characteristic exactly opposite to the dispersion in a transmission line to obtain a good waveform.

Since the dispersion characteristics of the dispersion compensating fiber 03 cannot be varied, it is general to prepare fibers having some dispersion characteristics and compensate for the dispersion according to the change in the dispersion characteristics of the transmission line.

However, the prior art has the following problems.

(I) Compensation for higher-order dispersion is difficult.

(Ii) It is necessary to prepare a large number of fibers to compensate for dispersion. In particular, an ultrahigh-speed optical signal has a narrow allowable range of dispersion, so that a fiber whose dispersion value is slightly changed is required. For this reason, the size of the device is increased and a multi-terminal optical switch is required.

(Iii) Since the dispersion compensating fiber is switched by the optical switch, an instantaneous interruption of the optical signal occurs during the switching.

As another example of the conventional technique, there is a configuration of a chirped fiber grating and an MZ interferometer connected in multiple cuts, but has the following problems.

(Iv) The control width of the central wavelength of dispersion compensation is small, and the compensation band is narrow.

In an ultra-high-speed optical transmission device, waveform distortion due to self-phase modulation in an optical fiber is a second cause of limiting the transmission distance. FIG. 7 shows another conventional example. In FIG. 7, reference numeral 04 denotes an optical transmitter, 05 denotes a high dispersion fiber, 06 denotes an optical amplifier, 07 denotes an optical transmission line, 08 denotes a dispersion compensation circuit, and 09 denotes an optical receiver.

This configuration is a transmission method for reducing self-phase modulation by widening a pulse width through an optical signal in advance in a high dispersion medium on the premise of dispersion compensation. Since the self-phase modulation occurs almost in proportion to the light pulse peak intensity, it can be reduced by increasing the pulse width and decreasing the peak power. The waveform can be reproduced by compensating for the dispersion, but the deterioration of the waveform due to the self-phase modulation, which is a nonlinear phenomenon, cannot be reproduced by the usual linear waveform equalization method. No transmission equipment is required.

However, the conventional technique has the following problems.

(V) Since the change in dispersion in the transmission path cannot be predicted in advance, the dispersion is accidentally equalized in the course of transmission, and there is a possibility that self-phase modulation occurs and the waveform deteriorates and errors increase. .

As described above, conventionally, as a means for shaping the picosecond pulse (for example, dispersion compensation), another optical fiber having a dispersion characteristic exactly opposite to the dispersion in the transmission line, a chirped fiber grating, and a multistage connection are used. There is an MZ interferometer. However, higher order dispersion compensation, variable dispersion compensation,
Broadband compensation is difficult. Further, in the related art shown in FIG. 1, the amount of dispersion that can be compensated is very small. For example, 2p
For an optical pulse having a pulse width of s, only compensation of about 5 ps / nm can be performed.

In the above-described optical signal processing device,
It is becoming necessary to observe higher-speed optical signal waveforms.

Conventionally, as a waveform measuring / recording means, there is an ultra-high-speed O / E converter or a streak camera.
However, the bandwidth of the O / E converter is at most 50 GHz, and it is impossible to measure a picosecond pulse of 1 to 10 ps. Further, since the streak camera has low sensitivity in the wavelength band of optical communication, sufficient S / N cannot be obtained by single sweep, and a real-time waveform cannot be observed. There is no research report using the prior art shown in FIG. If the conventional technique is applied as it is, light is two-dimensionally distributed on the Fourier transform surface, and it is difficult to measure with high S / N unless a special optical system is devised.

[0042]

The object of the present invention is to generate an optical pulse of 1 to 10 ps, shape the waveform,
An object of the present invention is to provide an optical signal processing device and an optical signal processing method that enable waveform measurement, waveform recording, correlation processing, and the like.

[0043]

The basic structure of an optical signal processing apparatus according to the present invention which is suitable for such a problem is an optical waveguide, and first means for equally dividing output light from the optical waveguide. A waveguide array for separating the output light, a second means for imaging the light output of the waveguide array, and a second means for forming an optical output of the waveguide array. And a mirror for receiving the incident light of an image and reflecting the incident light.

Alternatively, an optical waveguide, a first means for equally dividing the output light of the optical waveguide, and an assembly of optical waveguides whose optical path length changes at regular intervals, is a waveguide for separating the output light. A waveguide array, second means for imaging the optical output of the waveguide array, and receiving the light imaged by the second means, distributing the incident light on a straight line, and distributing the incident light on the straight line. And a spatial filter that modulates to a desired intensity or phase according to the position and reflects the reflected light.

Further, another configuration of the optical signal processing apparatus according to the present invention includes a first optical waveguide, a first means for equally dividing output light of the first optical waveguide, and an optical path length fixed. A first waveguide array which is composed of a collection of optical waveguides changing at intervals and splits the output light; a second means for imaging the optical output of the first waveguide array; A spatial filter that receives the incident light of the image formed by the means, distributes the incident light on a straight line, modulates the light to a desired intensity in accordance with the position on the straight line, and transmits the modulated light; Third means for entering a second waveguide array comprising an aggregate of optical waveguides whose optical path lengths change at regular intervals, the second waveguide array, and output light of the second waveguide array A fourth means for converging the light into one point, and a fourth means on which the output light of the fourth means is incident. Characterized in that it comprises an optical waveguide for.

Another configuration of the optical signal processing apparatus according to the present invention includes a reflection type spatial filter, a waveguide array composed of an aggregate of optical waveguides whose optical path length changes at regular intervals, and the reflection type spatial filter. First means for inputting the coherent light to the filter and simultaneously inputting the coherent light modulated by the reflective spatial filter to the waveguide array,
Second means for converging the output light of the waveguide array to one point.

Further, still another configuration of the optical signal processing device of the present invention includes a transmission type spatial filter, a waveguide array including an aggregate of optical waveguides whose optical path length changes at regular intervals, and
First means for inputting coherent light to the transmission-type spatial filter, and second means for inputting the coherent light modulated by the transmission-type spatial filter to the waveguide array
Means, and third means for converging the output light of the waveguide array to one point.

According to the optical signal processing method of the present invention, an optical signal is input to an optical signal processing apparatus having a waveguide array and a spatial filter, and the optical signal is converted into a frequency spectrum image. And performing a desired modulation by the spatial filter, and condensing the modulated frequency spectrum image at one point to obtain a new optical signal.

In this optical signal processing method, the optical signal processing device used is desirably the aforementioned optical signal processing device.

Another configuration of the optical signal processing method according to the present invention is directed to an optical signal processing apparatus having a waveguide array and a spatial filter on which a hologram image corresponding to a frequency spectrum of a desired optical signal is written. , An optical signal is generated by inputting coherent light.

Further, according to the present invention, it is possible to generate a short pulse by combining a predetermined optical component with the optical signal processing device having the basic configuration.

The basic configuration of such an optical signal processing device is as follows. In the optical signal processing device having the above-described basic configuration having a mirror, the oscillating light in the optical resonator is set at the resonance mode interval on the input side of the optical waveguide. Light modulating means for modulating at substantially the same frequency or an integer multiple thereof, and light amplifying means are provided, and the modulating means, the amplifying means, and the optical waveguide are sequentially coupled by an optical coupling means, and the light modulator A light reflecting mirror is provided on an end face not facing the coupling means, and a mirror formed on an end face of the second means is of a high reflection type, and a resonator is formed between these high reflection mirrors. Characterized in that short pulse light can be generated.

In this configuration for generating short pulse light, a plurality of output waveguides are arranged at a predetermined interval between the focal plane of one slab waveguide of the arrayed waveguide grating and the high reflection mirror. May be.

Similarly, the plurality of output waveguides may be arranged at equal intervals.

Similarly, the reflectivity of the high reflection mirror corresponding to each output waveguide may be different.

Similarly, a predetermined waveguide length difference for compensating dispersion in the optical resonator may be set in the plurality of output waveguides.

Similarly, instead of the high reflection mirror, a plurality of lens arrays arranged at predetermined intervals and a liquid crystal spatial modulator having a high reflection mirror on one side may be provided.

Similarly, a diffraction grating may be formed at a predetermined position on each of the plurality of output waveguides instead of the high reflection mirror.

Similarly, an optical multiplexer for multiplexing some or all of the plurality of output waveguides may be provided.

Similarly, the diffraction efficiencies of the diffraction gratings formed in each output waveguide may be different.

Similarly, a plurality of high reflection mirrors are arranged at predetermined intervals on the focal plane of one slab waveguide of the arrayed waveguide diffraction grating.

Similarly, a plurality of high reflection mirrors may be arranged at equal intervals.

Similarly, the reflectivity of the plurality of high reflection mirrors may be different from each other.

Similarly, a plurality of diffraction gratings may be formed at predetermined intervals in the focal plane of the slab waveguide instead of the high reflection mirror.

Similarly, a plurality of diffraction gratings may be arranged at equal intervals.

Similarly, a plurality of diffraction gratings may have different diffraction efficiencies.

Similarly, the positions of the plurality of diffraction gratings may be displaced in the direction normal to the focal plane of the slab waveguide.

Similarly, instead of the high reflection mirror, a groove may be formed in the focal plane of the slab waveguide, and a film in which a plurality of mirrors are laminated at a predetermined interval may be arranged in the groove.

Similarly, the light modulating means and the light amplifying means may be integrated.

Similarly, some of the components may be connected by optical fibers.

Similarly, the position of the high reflection mirror may be controlled by a fine movement mechanism.

Similarly, the interval between the high reflection mirrors may be changed in the normal direction of the slab waveguide.

Further, based on the optical signal processing device having the basic configuration of the present invention, a device configuration capable of observing the waveform of the optical signal to be processed is possible.

An optical signal processing apparatus capable of observing such a waveform comprises an optical waveguide, an array waveguide composed of a plurality of optical waveguides whose waveguide lengths are sequentially increased, and an output light from the optical waveguide. A spatial filter arranged near the focal plane of the imaging means for modulating an image of light, and a modulating means for modulating the light with the spatial filter. And a light branching means for taking out the reflected light from the reflecting means in the optical waveguide.

Alternatively, a first optical waveguide, a first array waveguide composed of a plurality of optical waveguides whose waveguide lengths are sequentially increased, and an output light of the first optical waveguide is supplied to the first array waveguide. Distribution means for distributing the light into a wave path; first imaging means for forming an image of the output light from the first arrayed waveguide; and modulation means for disposing a light image arranged near a focal plane of the first imaging means. And a second array waveguide including a plurality of optical waveguides whose waveguide lengths are sequentially increased, and a second array waveguide that forms an image of light modulated by the spatial filter on the second array waveguide. 2 imaging means, a second optical waveguide, and multiplexing means for multiplexing output light from the second arrayed waveguide and coupling the multiplexed light to the second optical waveguide. I do.

Further, a first optical waveguide, a first array waveguide composed of a plurality of optical waveguides whose waveguide lengths are sequentially increased, and an output light of the first optical waveguide are supplied to the first array waveguide. A distributing means for distributing the light into a waveguide, an optical waveguide for inputting reference light, a second arrayed waveguide composed of a plurality of optical waveguides whose lengths are sequentially increased, and an output light from the optical waveguide for inputting reference light. Second distribution means for distributing the light to the second array waveguide, imaging means for imaging the output light of the first array waveguide and the output light of the second array waveguide, and the imaging means And an optical recording medium disposed in the vicinity of the focal plane, and a light branching unit for extracting the reflected light from the first optical waveguide.

Further, another configuration of the apparatus capable of observing the waveform includes a first optical waveguide, a first arrayed waveguide composed of a plurality of optical waveguides whose waveguide lengths are sequentially increased, and the first optical waveguide. First distribution means for distributing the output light of the optical waveguide to the first array waveguide, a reference light incident optical waveguide, and a third array waveguide comprising a plurality of optical waveguides whose waveguide lengths are sequentially increased. A waveguide, second distribution means for distributing output light from the reference light incidence optical waveguide to the third array waveguide, and
First imaging means for imaging the output light of the array waveguide and the output light of the third array waveguide, and an optical recording medium arranged near a focal plane of the first imaging means; A second array waveguide including a plurality of optical waveguides whose waveguide lengths are sequentially increased, and a second imaging unit configured to image light modulated by the optical recording medium on the second array waveguide. Combining the second optical waveguide and the output light of the second array waveguide to form the second optical waveguide.
And a multiplexing means coupled to the optical waveguide.

Further, another configuration of the device capable of observing a waveform includes a first optical waveguide, a first arrayed waveguide composed of a plurality of optical waveguides whose waveguide lengths are sequentially increased, and the first optical waveguide. A second distributing means for distributing the output light of the waveguide to the first arrayed waveguide, a first reference light incident optical waveguide, and a plurality of optical waveguides whose waveguide lengths are sequentially increased. An array waveguide, second distribution means for distributing the output light of the first reference light incident optical waveguide to the second array waveguide, a second reference light incident optical waveguide, and the first First imaging means for imaging the output light from the array waveguide, the output light from the second array waveguide, and the output light from the second reference light incidence optical waveguide, and the first imaging An optical recording medium disposed in the vicinity of the focal plane of the means, and a second imaging device for imaging light modulated by the optical recording medium. Means, characterized in that it is composed of a light receiving device array arranged in the vicinity of the focal plane of the second imaging means.

In the apparatus capable of observing the waveform, the imaging means may be a slab waveguide having a circumferential end face.

Similarly, the imaging means may comprise a slab waveguide and a phase spatial modulation device.

Similarly, the spatial filter may be a phase filter, an intensity filter, or a spatial filter in which an intensity filter and a phase filter are connected in multiple stages.

Similarly, the focal length of the phase spatial modulation element may be equal to the focal length of the slab waveguide of the coupling means.

Similarly, a pattern mirror composed of a number of partial mirrors may be used as the spatial filter and the reflection means.

Similarly, the spatial filter may be a spatial filter that also functions as a phase spatial modulation element.

Similarly, the imaging means may be a lens.

Similarly, the imaging means may be a slab waveguide on the focal plane, and a phase adjustment array waveguide may be provided at an end of the slab waveguide, and the end of the phase adjustment array waveguide may be connected to the spatial filter. .

Similarly, the imaging means may be a slab waveguide at the focal plane, a phase adjustment array waveguide provided at the end of the slab waveguide, and an optical modulator array provided at the phase adjustment array waveguide.

Similarly, the phase difference between the waveguides of the phase adjustment array waveguide may be an integral multiple of 2π.

Similarly, the light branching means may be an optical circulator.

Similarly, the image forming means may be a slab waveguide, and a light bending means for bending light in a direction perpendicular to the waveguide may be provided at an end of the slab waveguide.

Similarly, the spatial filter may be a liquid crystal spatial modulator composed of a glass substrate, a transparent electrode, a liquid crystal, and a liquid crystal alignment film.

Similarly, a 波長 wavelength plate may be provided in the liquid crystal spatial modulator.

Similarly, the liquid crystal of the liquid crystal spatial modulator may be of a twisted nematic type.

In the optical signal processing method using the optical signal processing apparatus capable of observing a waveform, a time-series optical signal is input to the optical waveguide, thereby converting the time-series optical signal into a frequency spectrum image. A desired phase and / or intensity modulation is performed on the spectral image by the spatial filter, and the modulated light is combined to obtain a new time-series optical signal. Alternatively, the filter characteristic of the spatial filter is a hologram image of a pattern corresponding to a frequency spectrum of a desired time-series optical signal, and a desired optical signal is generated by injecting coherent pulse light into the optical waveguide. You may do it. further,
Signal light enters the optical waveguide, coherent pulse light reference light enters the reference light input waveguide, holograms are recorded on the recording medium, and another coherent pulse light reference light enters the reference light input waveguide. Alternatively, the light source may output a phase conjugate light of the signal light. Further, the signal light is incident on the optical waveguide, the reference light of the coherent pulse light is incident on the reference light input waveguide, and the hologram is recorded on the recording medium.
It may be characterized in that another reference light of coherent pulse light is made incident on the reference light input waveguide, and signal light or correlation light between the signal light and the reference light is output. Furthermore, the signal light enters the optical waveguide, the coherent pulse light reference light enters the first reference light input waveguide, and the monochromatic reference light enters the second reference light input waveguide. Alternatively, a spatial image of the signal light waveform may be formed on the photodetector array, and the pulse waveform may be observed.

Further, according to the present invention, it is possible to provide an optical signal processing device capable of performing dispersion compensation of an optical signal to be processed, based on the optical signal processing device having the above-described basic configuration.

An optical signal processing apparatus capable of performing such dispersion compensation includes a first optical amplifier, an optical wavelength filter, a first optical waveguide, and a plurality of optical waveguides whose waveguide lengths are sequentially increased. A first array waveguide comprising: a first optical waveguide; and a distribution unit for distributing the first optical waveguide output light to the array waveguide;
A first imaging unit for imaging the first arrayed waveguide output light, and a first imaging unit disposed near a focal plane of the first imaging unit;
A spatial filter for modulating an image of light, a reflecting means for reflecting the light modulated by the spatial filter, a light branching means for extracting the reflected light from the first optical waveguide, and a second
And an optical amplifier.

Another configuration of the optical signal processing device capable of performing the dispersion compensation includes a first optical amplifier, an optical wavelength filter, and a first optical amplifier.
An optical waveguide, a first arrayed waveguide composed of a plurality of optical waveguides whose waveguide lengths are sequentially increased, distribution means for distributing the first optical waveguide output light to the arrayed waveguide,
A first imaging means for imaging the output light of the arrayed waveguide, a spatial filter arranged near the focal plane of the first imaging means for modulating the light image, and a waveguide having a longer length. A second array waveguide including a plurality of optical waveguides, a second imaging unit configured to image light modulated by the spatial filter on the second array waveguide, and a second optical waveguide. , The second
And a second optical amplifier, which multiplexes the output light of the array waveguide and couples the multiplexed light to the second optical waveguide.

Further, an optical signal processing device comprising the dispersion compensation type optical signal processing device, a light source, an optical modulator, and an optical modulation signal generating circuit is also possible.

Further, an optical signal processing device comprising the above-mentioned distributed reward type optical signal processing device and an optical receiver is also possible.

Similarly, an optical signal transmission circuit including the dispersion compensation type optical signal processing device, a light source, an optical modulator, and an optical modulation signal generation circuit, and the dispersion compensation type optical signal processing device. An optical signal processing device including an optical signal receiving circuit including an optical signal receiver and an optical transmission path is also possible.

In the dispersion compensation type optical signal processing apparatus, the spatial filter is a phase filter, and the relative phase φ is relative to the position (x) on the spatial filter.

[0102]

[Equation 1] φ (x) = Mod [ax ² , π] (a: constant) may have a characteristic (Mod [u, v] is v
Indicates the remainder modulo. ).

Similarly, the spatial filter is a phase filter, and the relative phase φ is determined with respect to the position (x) on the spatial filter.

[0104]

[Mathematical formula-see original document] A characteristic approximating φ (x) = Mod [ax ² , 2π] (a: constant) may be obtained (Mod [u, v] is v
Indicates the remainder modulo. ).

Similarly, the spatial filter is a phase filter, and the relative phase φ is φ (x) = π / 2 (x> 0) and φ (x) = 0 with respect to the position (x) on the spatial filter. (X <
0) or φ (x) = 0 (x> 0) and φ (x) = π / 2 (x <
0) may be characterized by performing intensity modulation-angle modulation conversion having characteristics approximating (0).

Similarly, the spatial filter is a phase filter, and the relative phase φ is φ (x) = π (x> 0) and φ (x) = 0 (x <0),
Alternatively, it may be characterized by performing intensity modulation-angle modulation conversion having characteristics approximating φ (x) = 0 (x> 0) and φ (x) = π (x <0).

In the optical signal processing apparatus capable of dispersion compensation, the spatial filter may be constituted by a phase filter and an intensity filter.

Similarly, the spatial filter may be a liquid crystal spatial modulator composed of a glass substrate, a transparent electrode, a liquid crystal, and a liquid crystal alignment film.

Also, the optical signal processing method using the optical signal processing apparatus capable of dispersion compensation modulates the frequency spectrum phase of the optical signal generated by the optical signal transmitting circuit, and controls the dispersion in the optical fiber by the optical receiving circuit. And compensating for frequency spectrum phase modulation by the optical signal transmission circuit.

In another configuration of the optical signal processing method, the frequency spectrum intensity of the optical signal generated by the optical signal transmitting circuit is modulated, and the dispersion in the optical fiber is performed by the optical receiving circuit.
The frequency spectrum intensity modulation by the optical signal transmission circuit is compensated.

Similarly, another configuration modulates a frequency spectrum phase and a frequency spectrum intensity of an optical signal generated by the optical signal transmitting circuit, and the dispersion in the optical fiber and the optical signal transmitting The frequency spectrum phase modulation and the frequency spectrum intensity modulation by the circuit are compensated.

Still another configuration of the optical signal processing apparatus capable of dispersion compensation includes a short pulse light source, a first optical amplifier,
A first optical wavelength filter, first branching means for branching the output light of the first optical wavelength filter into n (integer) light beams, a first n light modulation circuits, a first arrayed waveguide composed of n input / output optical waveguides, a plurality of optical waveguides whose waveguide lengths are sequentially increased, and an optical waveguide output light of the first n input / output optical waveguides. First distributing means for distributing light to the first arrayed waveguide, first imaging means for imaging the output light of the first arrayed waveguide, and near a focal plane of the first imaging means. The first, which is arranged, modulates the image of light
, A first reflection means for reflecting light modulated by the first spatial filter, and a second light for extracting the reflected light from the first n input / output optical waveguides Branching means, first optical multiplexing means for multiplexing the reflected lights from the n second optical branching means, and second optical amplifier;
A first optical signal processing device comprising: an optical transmission line;
A third optical amplifier, a second optical wavelength filter, and the second
Third branching means for branching the output light of the optical wavelength filter into n (integer) light beams, second n input / output optical waveguides, and a plurality of optical waveguides whose waveguide lengths are sequentially increased A second array waveguide composed of: a second distribution waveguide for distributing optical waveguide output light of the second input / output optical waveguide to the second array waveguide; and a second array waveguide output. Second imaging means for imaging light, a second spatial filter arranged near the focal plane of the second imaging means for modulating an image of light, and modulation by the second spatial filter Second reflecting means for reflecting the reflected light; n fourth light branching means for extracting the reflected light from the second input / output optical waveguide;
N for receiving the reflected light from the n fourth light splitting means
And a second optical signal processing device comprising the two optical receivers.

Furthermore, another configuration of the optical signal processing apparatus capable of dispersion compensation includes a short pulse light source, a first optical amplifier,
A first optical wavelength filter, first branching means for branching the output light of the first optical wavelength filter into n (integer) light beams, a first n light modulation circuits, a first arrayed waveguide composed of n input / output optical waveguides, a plurality of optical waveguides whose waveguide lengths are sequentially increased, and an optical waveguide output light of the first input / output optical waveguide, First distributing means for distributing the light to the array waveguide, first imaging means for forming an image of the output light from the first array waveguide, and disposing near the focal plane of the first imaging means. A first spatial filter that modulates an image of light, a second arrayed waveguide composed of a plurality of optical waveguides whose waveguide lengths are sequentially increased, and a light modulated by the first spatial filter. A second imaging means for forming an image on the second array waveguide, a first n output optical waveguides, and the second array waveguide. First optical multiplexing means for multiplexing output light and coupling to the first n output optical waveguides; and second optical multiplexing means for multiplexing the output of the first n output optical waveguides Means, a first optical signal processing device comprising a second optical amplifier, an optical transmission line, a third optical amplifier, and a second optical amplifier.
Optical wavelength filter, third branch means for splitting the output light of the second optical wavelength filter into n (integer) light beams, second n input / output optical waveguides, and waveguide length And a third arrayed waveguide composed of a plurality of optical waveguides whose lengths are sequentially longer, and an optical waveguide output light of the second input / output optical waveguide is transmitted to the third arrayed waveguide.
A second distributing means for distributing to the array waveguides of
Third imaging means for imaging the output light of the arrayed waveguide, a second spatial filter disposed near the focal plane of the third imaging means for modulating the light image, and a waveguide length. A fourth array waveguide composed of a plurality of optical waveguides whose lengths are sequentially increased, and fourth imaging means for imaging light modulated by the second spatial filter on the fourth array waveguide; A second n output optical waveguides, third optical coupling means for multiplexing the fourth arrayed waveguide output light and coupling the multiplexed output light to the second n output optical waveguides; And a second optical signal processing device comprising n optical receivers for receiving output light from the two output optical waveguides.

Further, based on the optical signal processing device having the basic configuration of the present invention, it is possible to provide an optical signal processing device capable of observing the waveform of an optical signal to be processed in real time.

An optical signal processing apparatus capable of observing such a waveform is capable of converting a time-series optical signal of signal light into spatial signal light.
Time-space conversion means, second time-space conversion means for converting a time-series optical signal of reference light into spatial signal light, the first time-space conversion means, and the second time-space conversion Imaging means for forming spatial signal lights respectively output from the means and causing interference with each other, and interference light images of a plurality of optical signals which are arranged near the focal plane of the imaging means and which are incident on the imaging means And a light signal restoring circuit for restoring a time series signal of the signal light from a detection signal of the light receiving means.

In this optical signal processing apparatus capable of observing a waveform, the first and second time-space converting means are constituted by an arrayed waveguide grating, and the image forming means has a function of performing a Fourier transform on the spatial signal light. It may be constituted by a slab waveguide having the same.

Similarly, in the optical signal processing apparatus capable of observing the waveform, the first and second time-space converting means are constituted by diffraction gratings, and the image forming means is a lens for performing Fourier transform of the spatial signal light. May be configured.

Similarly, in the optical signal processing device capable of observing the waveform, the light receiving means may be constituted by a photodiode array.

Similarly, in the optical signal processing device capable of observing the waveform, the optical signal restoring circuit calculates the electric field distribution of the light pulse of the incident signal light from the electric field intensity distribution of the Fourier transform hologram detected by the light receiving means. May be restored by arithmetic processing.

The signal processing method using the optical signal processing apparatus capable of observing a waveform includes a step of converting a time-series optical signal of an unknown signal light into a spatial signal light, and a step of converting a time-series optical signal of a known reference light into a spatial signal light. And forming a spatial signal of the signal light and a spatial signal of the reference light into a hologram image of a pattern corresponding to the frequency spectrum of the time-series signal by causing the spatial light signal and the reference light spatial signal to form interference with each other. Forming, receiving the hologram image and converting it into an electric signal, and restoring the unknown signal light from the hologram image converted into the electric signal using a predetermined arithmetic expression. It is characterized by.

In this optical signal processing method, the step of restoring the unknown signal light from the hologram image is mathematically derived from the electric field distribution of the reference light known in the hologram image formed on the focal plane. It may have a mathematical operation for multiplying the electric field distribution of the reproduction light, followed by a Fourier transform operation and a space-time transform operation.

Further, in this signal processing method, the electric field distribution of the reproduction light on the focal plane to be multiplied by the hologram image is two times the absolute value of the amplitude distribution of the electric field distribution of the input known reference light on the focal plane. It may include a factor to divide by a power.

[0123]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below, but the present invention is not limited to the following embodiments.

(Embodiment 1) A method for processing an optical signal according to a first embodiment of the present invention and its configuration will be described with reference to FIG.

As shown in FIG. 8, the input optical signal u (t)
After being incident on the quartz waveguide 1, it is branched by the star coupler 2 into N waveguide arrays 3. The waveguide array 3 has ΔL between the entrance surface S ₁ and the exit surface S _2.
Are set so as to have an optical path length difference of Where S ₁
Is on the circumference centered on the incident end of the quartz waveguide 1 to the star coupler 2, and S ₂ exhibits the highest performance spectral characteristics when arranged on the circumference centered on the center of S _3. .

Therefore, at the output end from the waveguide array 3 to the slab waveguide 4, each light beam is nΔL
(N is the refractive index of the waveguide), it is known to have a demultiplexing function similar to a diffraction grating (for example,
H. Takahashi et al., IEEEJ. Lightwave Tech. Vol.12
(No.6), pp.989-995 (1994)); MK Smit Electron.Let
t. vol. 24, pp. 385-386, (1988); C. Dragone et al.,
IEEE photon. Technol. Lett., Vol.3, pp.896-899 (19
91).

Conventionally, such waveguide arrays 2, 3, 4
Is well known for use as an optical demultiplexer in wavelength division multiplexed optical transmission.

The present inventors have discovered that when a time-series optical signal is incident on the waveguide array 3, the time-frequency spectrum of the optical signal can be formed as a spatial image without using a lens. Further, the present inventors have found a high-resolution waveguide array design method, and have devised an application to optical signal processing based on this principle.

That is, when the waveguide array is used, the Fourier transform U (n) of the incident optical signal can be spatially formed on the focal plane S ₃ of the slab waveguide 4.

It has been found that the frequency resolution is proportional to Nm when m-th order diffracted light is used. Where N is
This is the number of waveguides in the waveguide array 3. Therefore, if m is increased, a higher resolution can be obtained as compared with a normal diffraction grating whose frequency resolution is proportional to N. By optimally designing according to these guidelines, a waveguide array with extremely high optical resolution can be obtained, and spectral decomposition of a long optical pulse train at high speed becomes possible.

When the reflection-type spatial filter 5 is installed on the focal plane S ₃ of the high-resolution waveguide array as described above,
The spatial frequency pattern of the spatial filter 5 is represented by H (v)
Then, the light pattern of U (v) H (v) is reflected, returns to the array waveguide 3 and the star coupler 2, and is emitted from the quartz waveguide 1.

The output optical signal at this time is u (t) * h
(T). Here, * represents the convolution of two signals.

That is, by providing an arbitrary spatial filter 5, processing in the frequency domain of the incident signal light can be performed. The input and output between the outside and the quartz waveguide 1 are, for example,
This is performed using an optical fiber with a coupler.

In the configuration of FIG. 8, the focal plane S ₃ is equal to S ₂
On the circumference centered on the center of
Is a plane, the output waveform is generally distorted. Since this distortion is approximated when the phase changes in a quadratic function with respect to the center frequency, this configuration is approximately equal to having the second-order dispersion characteristic. In order to correct this, the input light or the output light may be transmitted through a dispersion medium having the same sign as that of the present configuration and having the same size. Alternatively, the spatial filter 5 may be designed to include the effect of compensating for the dispersion.

As a specific application example of this method, an optical signal u (t) passes through some device, for example, a long-distance optical fiber communication line, and f (t) = u (t) * h (t). Consider the case where such distortion has been received.

This distorted signal f (t) is converted to the original signal u
In order to return to (t), an optical signal processing device as shown in FIG. 9 can be used. FIG. 8 showing the principle of optical signal processing
In the apparatus shown in FIG. 9, the reflection type is used.
It was a transmission type.

As shown in FIG. 9, an optical signal f (t) having some distortion enters the quartz optical circuit 8 from the optical fiber 7 via the optical connector 6.

As shown in FIG. 10, the quartz optical circuit 8 includes waveguides 9 and 13, star couplers 10 and 14, waveguide arrays 11 and 15, and slab waveguides 12 and 16 with respect to a spatial filter 17. They are arranged symmetrically.

The waveguide arrays 11 and 15 may include a half-wave plate 1 on the way as needed to eliminate polarization dependency.
8, 18 are installed.

After the input signal light propagates through the waveguide 9, it is incident on the waveguide array 11 by the star coupler 10, and the Fourier transform F (v) is applied to the focal plane S ₃ in the slab waveguide 12.
= U (v) H (v) is imaged.

Here, when a spatial filter 17 having the following pattern is placed on the focal plane, the spatial filter 17 becomes U (v) by the product of the signal and the spatial filter.

H ^* (v) / | H (v) | ^{2 When} this passes through the slab waveguide 16, the waveguide array 15, and the star coupler 14, the optical signal u (t) that has been subjected to inverse Fourier transform and restored is converted into a waveguide. 13 can be taken out. If the attenuation is large in intensity, it is output to the outside by the optical connector 6 through the optical amplifier 19.

Here, the spatial filter 17 may be a fixed pattern or a rewritable pattern. In the case of a fixed pattern, a pattern having a predetermined phase and transmittance formed on a substrate such as a glass substrate by vapor deposition or the like may be provided. Also, to make the pattern rewritable,
An optical modulator made of liquid crystal or semiconductor is used as a spatial filter, and the phase and transmittance of each pixel on the optical modulator are controlled by a voltage output from the spatial filter control device 20.

Actually, using an optical circuit having the configuration shown in FIG. 10 and a fixed pattern spatial filter formed on a glass substrate, a single pulse width of 0.2 ps, a period of 0.5 ps, and a wavelength of 1500 nm composed of 100 pulses are used. It was confirmed that the distortion of the optical pulse train could be shaped.

(Embodiment 2) A method of generating an optical pulse and a configuration thereof according to a second embodiment of the present invention will be described.
This will be described with reference to FIG.

[0146] This embodiment is obtained by installing a reflective computer-generated hologram (CGH) 21 on the focal plane S _3.
In the computer Holgram 21, for example, the Fourier transform U (v) of a certain optical pulse train u (t) is written as a spatial frequency pattern.

Therefore, when the readout light enters the slab waveguide 23 from the optical waveguide 22, the light pattern U (v) reflected from the hologram propagates in the order of the slab waveguide 23, the waveguide array 24, and the star coupler 25. The light pulse train u (t) is emitted from the waveguide 26 by inverse Fourier transform according to the principle described in the first embodiment.

In this embodiment, the computer generated hologram 21 can be obtained simply by inputting a simple light pulse as readout light.
Can be generated.

As a modification of the present embodiment, for example, as shown in FIG. 12, a readout light also enters a waveguide array 43 via a waveguide 41 and a star coupler 42, and becomes a computer as a Fourier transform image. The light may enter the hologram 21. However, the reading light may be a short light pulse.

As another modified example of this embodiment,
For example, as shown in FIG. 13, a transmission type computer generated hologram 31 can be used. That is, when reading light enters the slab waveguide 34 from the waveguide 33 on the side opposite to the waveguide array 32, the light pattern u (v) transmitted through the hologram becomes the slab waveguide 35, the waveguide array 32, and the star coupler 36. , And subjected to inverse Fourier transform in the same manner as described above, and an optical pulse train u (v) is emitted from the optical waveguide 37.

Actually, using an optical circuit having the configuration shown in FIG. 11, a single pulse width of 0.2 ps, a period of 0.5 ps, and a pulse number of 100
The generation of an optical pulse train having a wavelength of 1500 nm was confirmed.

(Embodiment 3) A method and configuration for temporarily storing an optical pulse according to a third embodiment of the present invention will be described.
This will be described with reference to FIG. In the present embodiment, placing the photosensitive optical recording medium 51 in the focal plane S _3.

As shown in FIG. 14, the input optical signal u (t)
Is externally introduced into the device by an optical connector 52 and amplified by an optical amplifier 53. Next, the light is divided into signal light and reference light by the optical coupler 54, and the signal light enters the quartz optical circuit 55 as it is.

In the quartz optical circuit 55, as shown in FIG. 15A, the signal light enters the waveguide 56 and is branched by the star coupler 57 into the waveguide array 58.

[0155] Light emitted from each of the waveguide array 58 is propagated through the slab waveguide 59, in the focal plane S _3, the Fourier transform U of the incident light signal (v) spatially imaged.

On the other hand, the reference light split from the signal light is split by the optical coupler 54, passes through the optical modulator 60, enters the quartz optical circuit 55, and as shown in FIG. Pass through the reference waveguide 61 and enter the slab waveguide 59.

The star coupler 57 shown in FIG.
15B is an enlarged view of FIG. Here, the incident waveguide end of the waveguide array 58 is arranged on the circumference. On the circumference centered on the incident end from the reference waveguide 61 to the star coupler 57, or from the waveguide 56 to the star coupler. 57
At any point on the circumference centered on the incident end to Normally, the number of waveguides arranged on each circumference is set substantially equal.

As a result, U (v) is recorded as a hologram on the optical recording medium 51 by interference between the reference light and the signal light.

After that, if light having the same wavelength as the reference light enters the waveguide W2 as read light, U (v) recorded on the hologram is read, and the slab waveguide 59, the waveguide array 58, the star coupler The light pulse train u is subjected to inverse Fourier transform during propagation in the order of
(T) is emitted.

Here, the optical modulator 60 plays a role of cutting out an optical pulse for the reference light or the readout light from a part of the signal light.

According to such a principle, the light pulse train is stored.

In this embodiment, the reflection type configuration is shown. However, a configuration using a transmission type hologram by providing a reading waveguide on the opposite side of the hologram is also possible.
Further, similarly to FIG. 12, a configuration in which the reference light and the reading light are incident through the waveguide array is also possible.

As the optical recording medium 51, for example, a photorefractive element having a semiconductor multiple quantum well structure, a photosensitive film, or the like can be used.

It is also possible to provide a plurality of reference light waveguides and record multiple patterns of light pulse trains on the hologram in multiplex in accordance with each reference light.

If the optical sensor array is placed on the focal plane instead of the hologram medium and only the signal light is introduced without introducing the reference light, the power spectrum of the signal light can be observed.

(Embodiment 4) Using the configuration of FIG. 8, the number N of waveguide arrays is set to 340, and the diffraction order m is set to 59. For the incident light, the output of the Cr / YAG laser is band-limited by a wavelength filter, and the center wavelength is 1549 nm.
A pulse having a spectrum width of 2.3 nm and a pulse width of 1.1 ps was generated and used.

FIG. 16 shows a pulse waveform of incident light when an optical signal is generated with the above configuration. As a filter, 120 GHz and 240 GHz
FIGS. 17 and 18 show output waveforms when a reflection type intensity filter for generating a GHz pulse is provided and processed. 17 and 18 that the optical signal processing device and the optical signal processing method of the present invention function as designed.

FIG. 19 shows a case where a waveguide array is used and a case where a conventional diffraction grating and lens are used.
The relationship between the pulse width to be handled and the maximum number of pulses that can be processed is shown.

The first effect of the present invention is that the signal processing capability (processable pulse train length) is high in principle. FIG.
As is clear from the above, the configuration of the present invention has a longer pulse train length than the conventional configuration, and can be designed to match the pulse width of the optical pulse to be processed by changing the diffraction order (m). Using the formula, the maximum pulse train length that can be processed (T ₀ )
And the minimum pulse width (τ) is as follows.

[0170]

(Equation 3)

(However, in the prior art, m = 1, ν
₀ : center frequency, N: number of waveguides, in the prior art, the number of diffraction gratings irradiated with a light beam)

[0172]

(Equation 4)

(Conventional technology, d: groove spacing of diffraction grating, λ
₀ : center wavelength, f: lens focal length, H filter size,
α: constant (normally 0.3 to 0.4, depending on pulse shape)

[0174]

(Equation 5)

When performing dispersion compensation or the like using the present invention, the processing capacity is proportional to the pulse train length that can be processed. That is, the circuit of the invention has approximately ten times the capacity of the prior art.

The second effect is that the size of the apparatus can be reduced. In the prior art, the total length is 4f as is clear from FIG. 1, but provided that the distortion of the lens is small, at least f is required to obtain the performance of FIG.
= 10 cm or more and a diameter of 10 cm or more are required, the total length is about 60 to 70 cm, and the width / height is about 30 cm. Furthermore, if an optical fiber input / output optical system is included, the device becomes a very large device and cannot be mounted on an optical communication device. However, in the present invention, the optical circuit can be arranged to be bent in a plane, and the waveguide material has a higher refractive index than air. Therefore, the size is reduced, and in order to obtain the performance of FIG. Can be manufactured. In the case of a semiconductor waveguide, the size is about 5 cm square.

A third effect is that integration with other optical circuits becomes possible. For example, a built-in optical amplifier enables low-loss optical signal processing.

The effects when applied to the picosecond pulse generation means are that a pulse train close to the transform limit can be easily generated by dispersion compensation in the resonator, and the pulse shape can be designed by controlling each mode. is there.

When the present invention is applied to a dispersion compensating circuit, high-order dispersion compensation, variable dispersion compensation, and high-band compensation can be performed. In addition, for an optical pulse having a pulse width of 2 ps, 1
Compensation up to about 00 ps / nm is possible. In addition, by disposing a kinoform (Fresnel lens) between the slab waveguide and the filter / mirror, waveform shaping without distortion is possible.

The effects of the present invention when applied to a transmission apparatus are that dispersion compensation following a change in dispersion of a transmission line is possible, a system configuration in which transmission waveform deterioration due to self-phase modulation is reduced is possible, A modulation-to-angle modulation conversion circuit can be easily configured.

(Embodiment 5) FIG. 20 shows a fifth embodiment of the present invention.
1 shows an embodiment of the present invention. In the apparatus of this embodiment, a slab waveguide formed on a quartz substrate 101 by a first slab waveguide 105 for distributing the output light of the optical waveguide 104 and a plurality of optical waveguides having sequentially increased waveguide lengths. 10
The arrayed waveguide 106 that varies the optical path length of the distributed light 5 to generate a phase difference and separates the light, and the second slab waveguide 107 having a circumferential end face and having a lens function are integrated. . Reference numeral 200 denotes an arrayed waveguide diffraction grating.

The signal light is input to the quartz substrate 101 through the optical fiber 103 on the light input side, and an optical circulator 102 for extracting the return reflected light is interposed in the optical fiber 103. . In this case, the same function can be used with the optical fiber coupler, but the excess loss is at least 6 dB.

On the other hand, on the light output side of the quartz substrate 101, there are a Fresnel lens 108, a phase spatial modulation element represented by a kinoform, a spatial filter 109, and a mirror 110 serving as a reflection means.

FIG. 21 is an enlarged view of a Fresnel lens 108 and a spatial filter 109 which are phase spatial modulation elements provided on the quartz substrate 101. As shown in FIG. 21A, a Fresnel lens (Kinoform) 108, a holding substrate 113, and a spatial filter 10 are sandwiched between quartz substrates 111.
9. A mirror 110 is provided, and a low reflection filter 112 is formed on the surface of the Fresnel lens (Kinoform) 108 and the surface of the spatial filter 109. In this case, as shown in FIG. 21B, the side surface shape of the Fresnel lens (Kinoform) 108 is formed such that the contour portion has an elliptical shape, and the curvature in the short-axis direction is equal to that of the lens surface and the slab guide. The optical distance from the end face of the waveguide 107 is set to the focal length, the curvature in the long axis direction is equal to the focal length of the slab waveguide 107, and a transparent material is manufactured by etching in the operating wavelength range. Can be. The structure of the Fresnel lens 108 and the method of manufacturing the same will be described in more detail in the following embodiments.

Although the film thickness is larger than that of the Fresnel lens, a spherical or aspherical lens or the like may be manufactured by etching a thin film and used instead of the Fresnel lens. The manufacturing method is the same as that of the Fresnel lens.

The functions according to the configurations shown in FIGS. 20 and 21 are as follows.
Essentially transparent to the function of the conventional configuration shown in FIG.
Regarding the upsizing which is one of the problems in the prior art, for example, in the case of a repetitive signal with a pulse interval of 50 ps and a pulse width of 2 ps (upper part in FIG. 22), an optical system having a beam diameter of at least 15 mm or more is required In consideration of the effective diameter of the lens, a device having a size of about 50 × 100 cm is required. On the other hand, in the present example, it is sufficient to provide an optical path difference of up to about 10 mm in the quartz waveguide, so that it can be integrated on a substrate of about 5 × 5 cm, and a remarkable difference in size occurs.

The first slab waveguide 105, the array waveguide 106, and the second slab waveguide 107 are integrated on a quartz substrate.
Is to make the adjacent waveguides have different waveguide lengths by ΔL, and when the refractive index of the waveguide is n, the adjacent waveguide is n
It will have an optical path difference of ΔL. That is, the array waveguide 106 has the same demultiplexing function as the diffraction grating.

The emission end of the arrayed waveguide 106 is formed in a circular shape with a radius f and connected to a second slab waveguide 107. The second slab waveguide 107 has a focal length f
Functions as a lens. That is, the lens has a Fourier transform function of an image between the focal planes on both sides of the lens near the optical axis, but the second slab waveguide 107 also has a one-dimensional Fourier transform function of the output image of the array waveguide 106. Having. Note that the focus of the second slab waveguide 107 is
Since the second slab waveguide 107 is located on the circumferential surface on the optical axis, a Fresnel lens (Kinoform) 108 is provided on the emission side so that the focal plane is flat. In addition, Fresnel lens (Kinoform) 10
The focal length in the waveguide plane of No. 8 is set equal to the above-mentioned f. The arrangement of the spatial filter 109 for performing modulation via the low reflection coating 112 and the mirror 110 for reflection is as shown in FIG. 21A, but the Fresnel lens (Kinoform) 108 and the spatial filter 109
The phase filter can be manufactured by etching a transparent material at the operating wavelength to form a step, and by adjusting the exposure amount of the photosensitive material by direct writing of the electron beam, it is possible to reverse the exposure amount. Since the thickness to be developed is determined in proportion, a desired shape can be manufactured. Further, it is also possible to manufacture the Fresnel lens 108 and the spatial filter 109 by etching the substrate using the photosensitive material as a mask and processing the shape of the substrate. In the case of an intensity filter, it can be manufactured by etching the light absorbing film into a strip shape and controlling the line space ratio. Note that whether to use a phase filter or an intensity filter is difficult in terms of design in the former case and large in loss in the latter case. Therefore, it is only necessary to use either one according to the purpose or to provide both. .

The upper part of FIG. 22 shows an incident pulse waveform which is a repetitive signal having a pulse interval of 50 ps and a pulse width of 2 ps.
This incident signal light passes through the circulator 102 shown in FIG. 20, enters the optical waveguide 104, and is distributed to each waveguide of the array waveguide 106 by the first slab waveguide 105. Next, the light is demultiplexed in the array waveguide 106 based on the optical path length difference, Fourier-transformed in the second slab waveguide 107, and passed through a Fresnel lens (Kinoform) 108 to a spatial filter (here, temporarily a phase filter). ) 109
, Is reflected by the mirror 110 and returned, subjected to inverse Fourier transform, and extracted from the optical circulator 102 as output light. The lower part of FIG. 22 shows the emission light waveform, and the pulse repetition is five times.

In this case, the spatial filter 109 has a relative phase position dependency shown in the middle part of FIG.

Assuming that the pulse width of the light pulse to be processed is t ₁ and the center frequency is v ₀ , the light amplitude oscillates n times within the pulse.

[0192]

N = v ₀ t ₁ At this time, when the phase change d satisfies the following equation,

[0193]

[Mathematical formula-see original document] n ≧ d / 2π

[0194]

## EQU8 ## d'≡Mod [d, 2π] may be approximated (where [u, v] is a remainder modulo v).

That is, in the reflection type configuration, since light passes through the phase filter twice, the filter can be manufactured with a maximum phase change of π.

In the case of the transmission type, the phase change is d ″ ｄ
Mod [d, π] may be approximated, and a filter can be manufactured with a maximum phase change of 2π.

Of course, although the film thickness is increased, it goes without saying that a phase filter capable of obtaining a required phase modulation amount may be used.

The upper part of FIG. 23 shows the frequency spectrum of the incident signal, and the lower part of FIG. 23 shows the frequency spectrum of the signal light after passing through the spatial filter 109. Note that the lower part of FIG. 23 shows only phase modulation and no change in spectrum.

Thus, the modulation of the time-series waveform can be performed.

If this modulation is expressed by a mathematical formula, the transmission function (round trip) of the u (t) filter is represented by h (x)
Where t is time and x is a structural position on the filter. The frequency spectrum image is represented as U (ν (x)) using the Fourier transform U of u. Here, ν indicates the frequency related to the repetitive structure of the filter.

The spectrum after passing through the filter is S (ν
(X)) = U (ν (x)) · h (x). Then, the waveform of the emitted light is subjected to inverse Fourier transform, and s (t) = u
(T) * H (t). Here, * indicates a convolution integral.

As shown in FIG. 22, the pulse repetition frequency is five times, and the phase filter is composed of the same pattern repetition. The pattern is g (x) and the repetition period is ν ₁ (x ₁ ). Then, the repetition period of the pulse is 1 / ν ₁ (x ₁ ), its reciprocal.

In general, the pulse intensities in the cycle are different, and in order to make the pulse intensities uniform, it is sufficient that each pattern has a binary phase according to the M sequence. For example, the inside of the repetition cycle is divided into 15 parts. Each phase by (π, 0,0,0,
π, 0, 0, π, π, 0, π, 0, π, π, π).

Assuming that a desired waveform is s (t) and its Fourier transform is S (ν (x)), h (x) = S (ν (x)) /
A desired waveform can be obtained with a filter having a transmission function represented by U (ν (x)).

FIG. 24 shows a modification of the structure (Embodiment 5) of FIGS. 20 and 21. FIG. 24A shows a phase filter 109a for the spatial filter 109 described above.
An example in which both the phase filter and the intensity filter 109b are provided is shown, and there is an effect that the optical signal processing range is expanded by controlling both the phase and the intensity, unlike both the controls.

FIG. 24 (B) has the same function as FIG. 21, but shows an example in which a Fresnel lens (Kinoform) 108 is mounted on the upper surface of the filter, which facilitates manufacture. However, the focal length of the Fresnel lens (Kinoform) 108 must be f / ns when the refractive index of the slab waveguide 107 is ns.

FIG. 24C shows the mirror 11 shown in FIG.
Pattern mirror 1 serving both as 0 and intensity filter 109
14 shows an example in which 14 is formed, and the production is simplified.

FIG. 24D shows an example in which, instead of the slab waveguide 107 and the Fresnel lens (Kinoform) 108, a lens 115 is provided only in this portion. Fourier transform is possible.

FIG. 24 (E) shows the Fresnel lens 10
This shows an example in which a phase filter 116 having a function of the spatial filter 8 and the spatial filter (phase filter) 109 is provided, and the design is complicated, but the manufacture is easy.

The fifth embodiment has been described on the assumption that a quartz waveguide is used. However, semiconductor optical waveguides such as InP, GaAs, and Si, dielectric optical waveguides such as LiNbO ₃ , and organic material optical waveguides such as polyimide are used. It is needless to say that a similar optical circuit can be manufactured by the above method. In particular, since the semiconductor optical waveguide has a large refractive index, it can be further miniaturized, and an optical amplifier can be provided in an optical circuit.

(Embodiment 6) FIG.
21 shows an example in which the spatial filter shown in FIG. 21 is made of liquid crystal, where 301a and 301b are transparent electrodes, 302 is an alignment film, 303 is a spacer, 304 is a nematic liquid crystal, and 305 is a 波長 wavelength plate. The quarter-wave plate is necessary to make the polarization independent when a spatial filter having polarization dependence is used.
The axis is arranged at an angle of 45 degrees with respect to the waveguide surface (the line AA 'in FIG. 25A). For the alignment of the liquid crystal, a liquid crystal and an alignment film that are homogeneously aligned parallel or perpendicular to the waveguide surface (the AA ′ line portion in FIG. 25A) are used.

FIG. 25B shows the structure of the transparent electrode 301a, which has strip-shaped electrodes so that an arbitrary voltage can be applied to each electrode. When a voltage is applied, the orientation of the liquid crystal changes, and the transparent electrodes 301a, 301
Since the phase difference changes between b and the electrodes are provided in a strip shape, an arbitrary spatial phase filter can be realized. That is, in the present example, it is possible to perform optical signal processing as needed by adjusting the phase filter. Further, a twisted nematic liquid crystal may be used as the liquid crystal. In this case, a quarter wave plate is not required. When the applied voltage is sufficiently high, it functions as a polarization-independent phase modulator.

(Embodiment 7) FIG. 26 shows a seventh embodiment of the present invention.
In this embodiment, the optical path is bent to further reduce the size. 26, reference numeral 401 denotes a core of an optical waveguide, 402 denotes a mirror, and 403 denotes an oblique (7 to 8).
Degree) is the groove on the end face. In this example, a light bending portion is formed by the groove 403 and the mirror 402 for bending light so that the focal plane of the slab waveguide 107 is on the mirror 110.
In this example, the filter can be arranged on the quartz substrate, so that the size can be further reduced. The groove can be easily formed using a reactive ion etching apparatus.

(Embodiment 8) FIG. 27 shows a transmission type structure in which a first quartz substrate 101A having a first arrayed waveguide 106 and a second arrayed waveguide 505 are provided on a heat sink 101A. Second quartz substrate 101 having
B are arranged. The arrangement on the two quartz substrates 101A and 101B has a symmetric structure. That is, the first slab waveguide 105 for distribution, the first array waveguide 106, and the second slab waveguide 107 for imaging are integrated on the first quartz substrate 101A, The first slab waveguide 504 and the (second) array waveguide 5 for imaging also on the quartz substrate 101B.
05, a second slab waveguide 506 for multiplexing is integrated. Then, a spatial filter and the like are arranged between the quartz substrates 101A and 101B. Reference numeral 502 denotes an optical amplifier.

The first arrayed waveguide diffraction grating 200A is formed on a quartz substrate 101A on a heat sink 501,
The second arrayed waveguide diffraction grating 200B is also formed on the quartz substrate 101B on the heat sink 501, and is arranged symmetrically about the spatial filter. The first arrayed waveguide diffraction grating 200A includes an optical waveguide 104, a first slab waveguide 105, an arrayed waveguide 106, and a second slab waveguide 107. Similarly, the second array waveguide diffraction grating 200B also has the first slab waveguide 50B.
4, array waveguide 505, second slab waveguide 506,
And an optical waveguide 507.

FIG. 28 is an enlarged view. The spatial filter is the same as that of FIG. 25, but it is necessary to obtain at least a phase difference (2π) because it is a transmission type. Also, since the mirror 110 and the quarter-wave plate 305 in FIG. 25 are unnecessary, they are omitted. Since this configuration has polarization dependence, when making polarization independent, filters may be connected in two stages orthogonally. The transmission type configuration of this example is transparent in terms of operation and the configuration shown in FIG. Although the size of the device is increased, the loss can be reduced because the circulator 102 of FIG. 20 becomes unnecessary. Reference numeral 503 in FIG. 27 indicates a filter control device.

FIG. 29 shows a modification of the eighth embodiment shown in FIGS. 27 and 28. FIG. 29 (A) shows an example using a fixed spatial filter 109, and FIG. FIG. 29C shows an example in which a Fresnel lens (Kinoform) 108 is formed on a filter substrate, and FIG.
FIG. 29D shows an example using the first slab waveguide 10.
An example is shown in which a lens 115 is used instead of 7,504. In this case, since the spatial filter is a transmission type, a phase difference of at least (2π) can be obtained.

(Embodiment 9) FIG. 30 shows another example of the transmission type, in which the phase is adjusted by heating. That is, 601 is an array waveguide, 602 is a heating electrode, 603 is a wiring, and 604 is a control device. FIG. 31 shows an enlarged view of the arrayed waveguide 601. Here, 605 is a groove provided in the waveguide, 606 is a waveguide taper structure for reducing connection loss, and 607 is a half-wave plate.
The structures of the groove 605, the taper 606, and the half-wave plate 607 are structures that reduce the polarization dependence of the waveguide, and can be used for other arrayed waveguides as needed. Generally, since the refractive index of a material has temperature dependence, the optical path length, that is, the phase of the waveguide can be modulated by heating.
Here, it is possible to adjust the phase of each waveguide of the arrayed waveguide 601 by adjusting the current of the electrode 602. That is, if the incident end of the arrayed waveguide 601 is arranged so as to be a Fourier transform plane by the slab waveguide 107, the arrayed waveguide 601, the heating electrode 602, the groove 60
5, the taper 606 and the half-wave plate 607 function as a variable phase filter. In order to facilitate the phase control, the array waveguide 601 is manufactured so that the phase difference between the waveguides is an integral multiple of 2π. Also in this example, an arbitrary phase change and a flexible optical signal are possible as in the case of FIG.

It is to be noted that a spatial filter and a half-wave plate may be placed at the center and connected to the end of the phase adjustment array waveguide as shown by a virtual line in FIG.

(Embodiment 10) FIG. 32 shows an example of hologram recording, in which 701 is a reference light input waveguide, 702 is a slab waveguide as a second distribution means,
703 is a second array waveguide, and 704 is an optical recording medium. For the semiconductor layer 704, a semiconductor MQW, a photorefractive crystal such as barium titanate, a thermoplastic, or the like can be used. Here, the optical systems 104 to 10 of the signal light
6 and the reference light optical systems 701 to 703 have the same configuration.
When signal light enters the circulator 102 and coherent short-pulse reference light enters the optical waveguide 701, the signal light and the reference light undergo Fourier transform, interfere on the medium 704, and are recorded as holograms. After recording, when the coherent short pulse reference light is incident again, the circulator 102 outputs the phase conjugate light of the signal light. That is, this embodiment has a function of recording an ultra-high-speed optical signal and generating phase conjugate light.

(Embodiment 11) FIG. 33 shows another example of hologram recording, showing a transmission type. Where 8
01 is a slab waveguide as a second imaging means, 802 is an array waveguide, 803 is a slab waveguide as a multiplexing means, 8
04 is an optical waveguide. When signal light enters the first waveguide 104 and reference light enters the waveguide 701 as in the example of FIG. 32, an optical signal is holographically recorded on the waveguide 704.
After recording, when the coherent short-pulse reference light is incident again, the signal light is reproduced from the waveguide 804. If another signal light is incident instead of the reference light, it is possible to output a correlation signal between the two signal lights.

(Embodiment 12) FIG. 34 shows an example of waveform observation of an ultra-high-speed optical signal, in which reference numeral 901 denotes a monochromatic CW light source, 902 denotes an optical waveguide, 903 denotes a slab waveguide, and 904 denotes a slab waveguide.
Is an optical receiver array. When the signal light and the reference light enter the waveguide 701, the waveguide 104 is diffracted by the hologram on the medium 704. When the diffracted light forms an image on the array 904, a time waveform is formed as a spatial light intensity distribution.
By converting the signal into an electrical signal in the array 904 and converting it into a time-series signal in the parallel-serial conversion circuit 905, it is possible to observe the waveform of an ultra-high-speed optical signal. Further, the optical filter 906 sets the wavelength of the CW light source 901 to a wavelength different from that of the signal light and the control light as needed, so as to block the signal light and the reference light from entering the array 904.

In the description of the drawings, the same reference numerals denote the same parts.

The slab waveguide 10 as an imaging means
7,504 etc. are Fresnel lenses (Kinoform) 10
8, the focal plane is made flat. If the optical signal processing in the frequency space is not performed on the focal plane, large distortion generally occurs. However, depending on the degree of curvature of the focal plane, the Fresnel lens Etc. can be excluded. That is, the imaging means can be formed only of the slab waveguide.

In the description of each of the above figures, a spatial phase filter or an intensity filter may be used as described above, or both may be provided.

Also, in the example of FIG. 20, it has been described that the focal length of the Fresnel lens (Kinoform) is equal to the focal length of the slab waveguide of the coupling means. Can be determined.

The vertical bending means shown in FIG. 26B can be applied to, for example, FIG. 32. In this case, the spatial filter 109 and the mirror 11 shown in FIG.
0 is replaced with an optical recording medium.

As is clear from the above examples, the illustrations in the drawings of the embodiments can be applied to each other as needed.

(Thirteenth Embodiment) FIG. 35 shows a thirteenth embodiment of the present invention. The twelfth embodiment has a similar basic structure to that of the fourth embodiment, except that an optical amplifier 120, an optical filter 121, and an optical amplifier 122 are provided on the light source side.

FIG. 3 is a detailed configuration diagram near the Fresnel lens.
6 is shown. Here, in FIG. 36, reference numeral 111 denotes a quartz substrate,
112 is a low reflection coating film, and 113 is a holding substrate.

The Fresnel lens 108 can be manufactured by etching a transparent material in the operating wavelength range.
The contour diagram of the Fresnel lens 108 has an elliptical shape.
The curvature in the minor axis direction of the Fresnel lens 108 has a focal length equal to the optical distance between the lens surface and the end face of the slab waveguide 107. Further, the curvature in the major axis direction of the Fresnel lens 108 is made equal to the focal length of the slab waveguide 107.

The signal light incident on the optical fiber 103 is
After being amplified by the optical amplifier 120 and unnecessary ASE light is removed by the optical filter 121, the ASE light passes through the circulator 102 and enters the optical waveguide 104. Next, the signal light is distributed to each waveguide of the arrayed waveguide 106 in the first slab waveguide 105. Each waveguide adjacent to the array waveguide 106 has a different waveguide length by ΔL. Therefore, assuming that the refractive index of the waveguide is n, adjacent waveguides have a phase difference of nΔL. That is, the array waveguide 106 has the same demultiplexing function as the diffraction grating.

For this reason, the array waveguide diffraction grating 200 composed of the first slab waveguide 105, the array waveguide 106 and the second slab waveguide 107 is conventionally used as a multiplexer / demultiplexer in a wavelength division multiplexing transmission apparatus. Used.

The emitting end of the arrayed waveguide 106 is connected to the second slab waveguide 107, but is arranged on the circumference of the radius f. That is, the second slab waveguide 10
Reference numeral 7 functions as a lens having a focal length f.

The focal plane of the second slab waveguide 107 is located on the optical axis of the second slab waveguide 107 on the circumference centered on the emission end of the array waveguide 106.

If the optical signal processing in the frequency space according to the present invention is not performed on the focal plane, large distortion generally occurs.
Therefore, the Fresnel lens 108 is connected to the slab waveguide 1.
07 on the exit side. The focal plane is converted to a plane by the Fresnel lens 108. Fresnel lens 108
Is set equal to f in the waveguide plane.

The incident light transmits through the spatial filter 109, is reflected by the mirror 110, and transmits through the spatial filter 109 again.

FIGS. 37 and 38 show spatial filter 109.
3 shows a detailed view of the Fresnel lens 108. here,
The spatial filter 109 and the Fresnel lens 108 can be manufactured by a similar process. The thickness of the spatial filter 109 is the center wavelength λ _{0 of the} signal, and n _L is the spatial filter 10.
Assuming that the refractive index of the material is 9, the reflection type has a maximum of 2π for reciprocation.
Λ ₀ / (2n _L ).

In the Fresnel lens, light is emitted from the inside of the lens to the air.
In this example, the focal plane of the second slab waveguide 107 is converted into a plane, so that the second slab waveguide 107 is designed to have a focal length equal to that of the second slab waveguide 107.

The curvature in the direction (y) perpendicular to the waveguide substrate is such that the focal length in the quartz substrate 111 is equal to the thickness of the quartz substrate 111 in order to convert the light emitted from the lens into parallel light. Is set to Assuming that the curvatures in the x and y directions are R _x and R _y , the elliptical ring of the Fresnel lens 108 is represented by the following equation (1).

Note that m = 1, 2,... (Integer) corresponds to discontinuity of a curved surface.

[0242]

(Equation 9)

The curvature R and the focal length f are converted by the following equation (2).

[0244]

R = (n _L −1) f (2) The spatial filter 109 and the Fresnel lens 108 can be manufactured by, for example, exposing PMGI (PolyMethiGlutarImide) with an electron beam exposure machine and developing it.

FIG. 39 is a graph showing the dependence of the development depth of PMGI on exposure.

Further, the quartz substrate 111 can be manufactured by etching using the PMGI as a mask. This is shown in FIG.

Since the shape is inverted, an inverted exposure pattern is required if necessary.

It goes without saying that a replica may be produced based on the quartz substrate 111.

In order to express by an equation, the incident signal light is expressed by u
(T), the transmission function (round trip) of the spatial filter 109 is represented by h
Assume (x).

Here, t is time, x is the spatial filter 10
9 above.

The signal light u (t) passes through the array waveguide 10
6 and focuses on different positions x on the spatial filter 109. The separated frequency spectrum image is represented as U (ω (x)) using the Fourier transform U of u. The spectrum after passing through the spatial filter 109 where the center frequency of the signal corresponds to x = 0 is expressed by the following equation (3).

[0252]

U (ω (x)) · h (x) (3) The reflected light again passes through the arrayed waveguide 106 and undergoes inverse Fourier transform.

When light passes through a medium having group velocity dispersion, the input / output relationship in the frequency space is expressed by the following equations (4) and (5).

[0254]

(Equation 12)

Here, ω is the angular frequency and ω ₀ is the central angular frequency, the first term of the phase term indicates the absolute phase, the second term indicates the position on the time axis, and the third term indicates the group velocity dispersion. . The fourth and subsequent terms show higher-order dispersion effects. The pulse spread mainly occurs due to the effect of the third term.

However, if a phase filter represented by the following equation (6) is prepared and transmitted through the phase filter after the Fourier transform in the optical circuit of the present embodiment, the third term is obtained from the above equation (3). Since cancellation is possible, waveform deterioration due to group velocity dispersion can be equalized.

[0257]

(Equation 13)

As shown in FIG. 40, the phase filter can be manufactured by etching a transparent material in the operating wavelength band. Since it is difficult to manufacture a filter having a large phase difference, it is preferable to manufacture the filter by folding the filter with a phase difference of π in the reflection type configuration. In the case of the reflection type, since the light passes through the filter twice, the characteristic equation of the dispersion compensation filter is as follows.
The following equation is obtained.

[0259]

[Equation 14]

In the expressions (6) and (6 '), this approximation is effective for light having a pulse width of 100 fs or more. Needless to say, a filter having a thickness equal to the phase difference may be manufactured.

FIGS. 41 and 42 show examples of the filter characteristics of the twelfth embodiment. Here, assume that the characteristics of the dispersion compensating filter to compensate for changes in the Fourier phase of a medium of the group velocity dispersion is ax ² in the Fourier transform plane.

FIGS. 41 and 42 correspond to the positive and negative of the variance.

As a result, when the relative phase φ is relative to the position (x) on the spatial filter, φ (x) = Mod [ax ² , π]
An optical circuit having characteristics approximating (a: constant) can be manufactured (Mod [u, v] indicates the remainder of u relative to v).

In the thirteenth embodiment, only a fixed dispersion value can be compensated. However, if a filter for compensating up to higher-order terms of the above equation (5) is prepared, the above equations (3) to (6 ') are obtained. , Higher order dispersion can be compensated.

(Embodiment 14) FIGS. 25A and 25B show a fourteenth embodiment of the present invention.
This will be described with reference to FIG. The phase filter of the device of the present embodiment is shown in FIGS. 25A and 25B, and the other parts have the same configuration as that of the first embodiment shown in FIG. 35. Is omitted.

The １ ／ wavelength 305 is necessary to make the polarization independent when a spatial filter having polarization dependence is used. For the alignment of the liquid crystal, a liquid crystal and an alignment film that are homogeneously aligned parallel or perpendicular to the waveguide surface are used. 1
The f-axis and s-axis of the 波長 wavelength plate 305 correspond to the waveguide surface (FIG. 25).
(A-A 'line portion of (A)) is arranged at an angle of 45 degrees.

As shown in FIG. 25B, the transparent electrode 30
1-a is a strip-shaped electrode, and an arbitrary voltage can be applied to each electrode. When a voltage is applied, the orientation of the liquid crystal changes, and the phase difference between the transparent electrodes 301-a and 301-b changes. Since the electrodes are provided in a strip shape, an arbitrary spatial phase filter can be realized.
That is, in the present embodiment, by adjusting the phase filter, it is possible to change the central wavelength of dispersion compensation, change the amount of dispersion compensation, and perform dispersion compensation as needed.

(Embodiment 15) Embodiment 1 of the present invention
5 will be described with reference to FIG. 43 and FIG. 28 described above.

In FIG. 43, reference numeral 200A denotes a first arrayed waveguide diffraction grating, 200B denotes a second arrayed waveguide diffraction grating, 501 denotes a heat sink, 503 denotes a filter control device, and 504 denotes a second image formation. A slab waveguide,
505 is a second arrayed waveguide, 506 is a slab waveguide which is a multiplexing means, and 507 is a second optical waveguide.

The optical waveguide 104, the first slab waveguide 105, the array waveguide 106, the second slab waveguide 107, the first slab waveguide 404, and the array waveguide 5
05 and second slab waveguide 506, optical waveguide 507
Is a symmetrical structure.

The spatial filter of this embodiment (FIG. 28) is the same as that of the fourteenth embodiment, but it is necessary to obtain a double phase difference (2π) because it is a transmission type. Further, since a mirror and a quarter-wave plate are unnecessary, they are omitted. Since this configuration has polarization dependence, when making polarization independent, it is only necessary to connect two filters orthogonal to each other to obtain a phase difference (π). The transmissive configuration of this embodiment is equivalent in operation to the reflective configuration shown in the thirteenth and fourteenth embodiments.

(Embodiment 16) FIG. 44 shows Embodiment 16 of the present invention.

In FIG. 44, reference numeral 1001 denotes a light source,
1002 is an optical modulator, 1003 is an optical modulation signal generation circuit,
1004 is any one of the optical signal processing devices shown in the twelfth to fourteenth embodiments, 1005 is an optical transmission line composed of an optical fiber, an optical filter, an optical amplifier, etc., and 1006 is the twelfth to fourteenth embodiments. One of the optical signal processing devices 1007 shown in the embodiment example is an optical receiver.

In the transmission path, self-phase modulation, which is a major cause of signal deterioration, occurs almost in proportion to the light pulse peak intensity. The self-phase modulation can be reduced by increasing the pulse width and lowering the peak power while maintaining the average power.

In this embodiment, the optical signal processing device 100
In step 4, phase modulation is performed, the waveform is scrambled, the light intensity is flattened, and the peak intensity of the optical signal is reduced.

FIG. 45 shows a time waveform of the output light intensity of the modulator.
An example of an output waveform after transmission through the optical signal processing device 1004 is shown.

The dispersion of the transmission line is mainly the group velocity dispersion of the third term of the above equation (3), and is a quadratic term with respect to the frequency.

When the scrambling by the phase filter of the optical signal processing device 1004 is mainly performed by the second-order terms, the waveform is reproduced by compensating for the dispersion characteristic of the transmission line in the middle of the transmission line, and the self-phase modulation is greatly generated, and the waveform is regenerated. May be degraded beyond compensation. For this reason, the characteristic of the phase filter is such that if the term is a quadratic term, the dispersion of the same sign as the dispersion of the transmission path occurs. Alternatively, a third-order or higher-order term is used, or a filter having a completely random phase change is used.

In the case where the optical signal processing apparatus of Embodiment 13 is used, examples of the phase filter are shown in FIG. 46 (using a third or higher order term) and FIG. 47 (a completely random phase change).
Shown in The phase filter of the optical signal processing device 1006 on the receiving side is designed so as to compensate for dispersion and phase scrambling given in advance by the optical signal processing device 1004 in the transmission path. In order to express by a mathematical expression, u (t) represents the signal light output from the optical modulator 1002, and h ₁ (ω represents the characteristic of the phase filter of the optical signal processing device 1004 (reciprocation in the case of the reflection type).
(X)) (where the Fourier transform is H ₁ (t)) and the waveform distortion caused by the dispersion of the transmission path is J (t), the signal light s (t) incident on the optical signal processing device 1006 becomes (7)
Is approximated by In the formula, * means convolution.

[0280]

S (t) = u (t) * H ₁ (t) * J (t) (7) In order to reproduce the original waveform, the characteristic of the phase filter of the optical signal processing device 506 is changed as follows. What is necessary is just to determine like Formula (8).

[0281]

(Equation 16)

In some cases, the modulation of the optical spectrum intensity on the transmitting side can improve the optical S / N on the receiving side. That is, since the S / N is not uniform with respect to the frequency, the optical signal processing device 504 emphasizes and transmits the signal of the low S / N frequency using the intensity filter, and reduces the dispersion of the transmission line on the receiving side. If a phase filter to be compensated and an intensity filter having characteristics opposite to those of the transmitting side are used, the S / N is equalized with respect to the frequency, and the receiving sensitivity can be increased.

Further, a low frequency component of the time waveform is attenuated by using a filter for reducing only the vicinity of the center frequency as an intensity filter of the optical signal processing device 1006 on the receiving side, thereby reducing intersymbol interference caused by a non-linear effect or the like. Thus, the receiving sensitivity can be increased. FIG. 48 shows the characteristics of such an intensity filter.

(Embodiment 17) Embodiment 1 of the present invention
FIG. 49 shows the characteristic diagram of the phase filter of FIG.
(A) and FIG. 49 (B). The configuration of the circuit other than the filter is the same as in the thirteenth to sixteenth embodiments. It is assumed that the incident signal light is intensity-modulated signal light. FIG. 50A shows the frequency spectrum amplitude of the intensity modulation signal. Sidebands occur above and below the carrier frequency. On the other hand, the spectrum amplitude of the angle-modulated signal light has the shape shown in FIG. 50B, and the point where the phases of the upper and lower sidebands are inverted is a difference from the frequency spectrum amplitude of the intensity modulation. .

That is, as shown in FIGS. 50A and 50B, when the characteristic of the phase filter is a reflection type, φ (x) = π / 2 (x> 0) and φ (x) = 0 (x <
0) or φ (x) = 0 (x> 0) and φ (x) = π / 2 (x <
0), the conversion of the modulation format from the intensity modulation to the angle modulation is performed. It goes without saying that the inverse conversion may be performed using a filter whose phase has been inverted. Further, in the transmission type filter, since the amount of phase change is doubled, φ (x) = π (x> 0) and φ (x) = 0 (x <0);
Alternatively, φ (x) = 0 (x> 0) and φ (x) = π (x <0) may be set. Since the angle-modulated light has a substantially constant light average intensity, a nonlinear effect hardly occurs and the transmission distance can be extended.

Also, as in the sixteenth embodiment, a signal having a low S / N frequency is emphasized and transmitted using an intensity filter, and the receiving sensitivity is used on the receiving side using an intensity filter having characteristics opposite to those of the transmitting side. It is possible to increase.

(Embodiment 18) Embodiment 1 of the present invention
8 is shown. 51, reference numeral 1011 denotes a short pulse light source, 1012 denotes an optical amplifier, 1013 denotes an optical wavelength filter, 1014 denotes an optical branching device, 1015 denotes n optical modulation circuits, 1016 denotes n optical circulators, and 1017 denotes an optical circulator. n
The input waveguide 1018 is an optical multiplexing / demultiplexing device, and 1019
Is an optical amplifier, 1020 is an optical transmission line, 1021 is an optical amplifier, 1022 is an optical wavelength filter, 1023 is an optical branch element, 1024 is n optical circulators, and 1025 is n
Light receiving circuits.

The difference from the seventeenth embodiment described above is that optical signals are mainly multiplexed.

In the case of optical communication using short pulses, the bandwidth of light is generally determined by the pulse width.

If the minimum pulse interval can be reduced to about the pulse width, the band can be used effectively.

However, since the operating speed of the modulation circuit is at most 50 Gbit / s, the band (about 400 GHz in a Gaussian waveform) in the case of a pulse width of 1 ps cannot be used effectively. For this reason, in this embodiment, the pulse is branched and modulated into n modulation circuits in order to keep the operating speed range of the modulation circuit.

In the present embodiment, different modulation signals are added to each modulation signal in the frequency domain and then multiplexed / multiplexed.

In this case, the phase modulation for each modulation signal is performed so that the correlation between them becomes small.

In such phase modulation, for example, different P
N (Pseudorandom Noise) series and M (Maximum Length cod
e) A sequence may be used.

The phase of the spatial filter follows the sequence [1, 0]. In the reflection type configuration, the relative phase is [0, π / 2].
It is configured by changing with.

FIG. 52 shows the envelope of the average light intensity distribution on the filter plane.

Although the center frequency of each modulated signal is the same,
On the filter plane, an image is formed at a different position reflecting that the position of the input waveguide is different.

The light intensity distribution corresponding to the (k−1), k, and k + 1-th channels is determined by the slab waveguide 10 of the input optical waveguide.
5 at a distance equal to the distance d _in at the connection to 5.

For this reason, it becomes possible to perform different phase modulation on each modulation signal in the frequency domain. The phase-modulated light is an optical circulator 1016 and the light signal is an element 1018.
And are multiplexed.

On the receiving side, the optical signal is branched into n signals, and each of the branched signals is demodulated in the frequency domain using a spatial filter having a phase conjugate with the optical signal processing device on the transmitting side.

If the correlation of each modulation is small, other signal waveforms are not reproduced, and only average background noise is present.

In order to discriminate the presence / absence of a pulse from background noise, the receiving circuit must have a high-speed response to the pulse. For ultra-high-speed discrimination, an optical nonlinear element or a nonlinear light-receiving element is used, or a high-speed photoelectric conversion element and a flip-flop circuit are used.

FIG. 53 shows the waveforms of the modulated signal, the demodulated signal after the phase modulation, and the reproduced signal. That is, the present embodiment functions as a spread spectrum transmission apparatus in the optical frequency domain. As the number of multiplexes increases, it becomes more difficult to reduce the correlation of phase modulation for all combinations, so that background noise increases and multiplexing becomes more difficult, but the band corresponding to the pulse width is reduced by about 50%. It can be used with efficiency.

For example, using 1 ps pulses, 4 channels at a channel modulation speed of 50 Gbit / s, a total of 20 channels
It is possible to configure a transmission device of about 0 Gbit / s.

(Embodiment 19) Embodiment 1 of the present invention
9 is shown. In FIG. 54, reference numeral 1031 denotes a short pulse light source, 1032 denotes an optical amplifier, 1033 denotes an optical wavelength filter, 1034 denotes an optical branching element, 1035 denotes n optical modulation circuits, 1036, 1037, and 109 denote FIG. This is a transmission type optical signal processing device similar to that described above, wherein the input / output waveguide is n
1038 is an optical element, 1039 is an optical amplifier, 1040 is an optical transmission line, 1041 is an optical amplifier,
1042 is an optical wavelength filter, 1043 is an optical branching element, 1
Reference numerals 044, 1045, and 109 denote transmission optical signal processing devices similar to those shown in FIG.
Light receiving circuits.

In this embodiment, the first embodiment described above is used.
8 is composed of a transmission type phase modulation circuit, and its operation is the same as that of the eighteenth embodiment.

However, since it is a transmission type, the spatial filter is formed by changing the relative phase at [0, π].

(Embodiment 20) FIG. 55 shows Embodiment 20 of the present invention. The device of Embodiment 20 is a short pulse light source.

In the figure, the short pulse light source of the present invention includes an optical modulator 2011, a driving circuit 2012 for driving the optical modulator 2011, an optical amplification medium 2013, and an excitation circuit 2014 for forming an inversion distribution in the optical amplification medium 1013. 5, an optical modulator (optical modulation means) in which the input waveguide 71 is omitted from the array waveguide diffraction grating 62 shown in FIG.
The optical coupling unit 2016 includes an optical coupling unit 2016 that couples the optical amplifying medium (optical amplifying unit) 2013 with the optical amplifying medium 2013 and an optical coupling unit 2017 that couples the optical amplifying medium 1013 and the arrayed waveguide diffraction grating 2015. Optical coupling means 20 of optical modulator 2011
On the 16 side, a low reflection coating 2018 is applied, and on the opposite side (outside), a high reflection mirror 2019 is arranged. Optical coupling means 201 of arrayed waveguide diffraction grating 2015
The low-reflection coating 2020 is provided on the seventh side, and the high-reflection mirror 2021 is disposed on the opposite side (outside).

Note that an MQW modulator, an LN modulator, or the like can be used as the optical modulator 2011. As the optical amplification medium 2013, a traveling-wave semiconductor optical amplifier, a rare-earth-doped optical fiber amplifier, or the like can be used. The pump circuit 1014 is a current source when the optical amplifying medium 1013 is a traveling-wave type semiconductor optical amplifier, and is a pump light source when the optical amplifying medium 1013 is a rare earth-doped optical fiber amplifier. In addition, as the substrate 70 of the arrayed waveguide diffraction grating 2015, a semiconductor substrate such as InP or GaAs can be used in addition to a quartz substrate.

[0311] The arrayed waveguide diffraction grating 2015 is
A slab waveguide 72, an arrayed waveguide 73 composed of a plurality of waveguides which are sequentially elongated by a waveguide length difference ΔL, a slab waveguide 74, and a plurality of output waveguides 75 are formed on the optical waveguide 0.

Here, the refractive index of the slab waveguides 72 and 74 is n _s , the refractive index of the array waveguide 73 is n _c , the interval of the array waveguide 73 at the slab waveguide end face is d, and the center of the slab waveguide 74 is d. Assuming that the imaging direction with respect to the axis is θ, the focal length is f _s , and the wavelength of light is λ, the imaging position is

[0313]

[Mathematical formula-see original document] n _s d sin θ + n _c ΔL = mλ (m
= 1, 2,...). The value of m is usually several tens to several hundreds. Frequency of light incident on slab waveguide 72 and slab waveguide 7
The relationship between the imaging positions x on the focal plane 4 is as shown in FIG. Note that the linear dispersion (dx /
_{df = f s · dθ / df} ) is a 1 [μm / GHz].

The light incident on the slab waveguide 72 is reflected by the high reflection mirror 2021 via the output waveguide 75 connected to the end face of the slab waveguide 74 at an interval of Δx, and is again reflected from the slab waveguide 72 in the opposite direction. Is emitted. The reflection spectrum of such an arrayed waveguide diffraction grating 2015 depends on the interval Δx of the output waveguide 75 and the core width. For example, FIG. 57 shows a reflection spectrum when Δx is 50 μm and the core width is 10 μm. Depending on the arrangement of the output waveguide 75, a reflection spectrum having a reflection peak at every 50 GHz is obtained.

In the configuration of this embodiment, the high reflection mirror 2
An optical resonator is formed between the optical amplifier 019 and the high-reflection mirror 2021, and when the gain in the optical amplification medium 2013 is sufficiently large, light of many wavelengths can be oscillated simultaneously. Further, when the drive circuit 2012 drives the optical modulator 2011 with the limited wave of the frequency f to apply sufficiently deep modulation, coupling occurs between the oscillation longitudinal modes, and mode-lock oscillation occurs. Note that the driving frequency f is determined by setting the equivalent optical distance between the high reflection mirror 2019 and the high reflection mirror 2021 to L _eff and k to an integer.

[0316]

F = k · c / (2 · L _eff ) = Δx / (dx / df) At this time, the phase relationship of each longitudinal mode is kept constant, and an optical short pulse train having a repetition frequency f is generated. The oscillation wavelength spectrum is shown in FIG. 58, and the oscillation pulse waveform is shown in FIG.

With the conventional mode-locked laser, it was difficult to set the frequency of each mode. However, in the configuration of the present embodiment, since the frequency of each mode is determined by the interval Δx between the output waveguides 75 of the arrayed waveguide grating 2015, the frequency of each mode can be set in detail. Further, the array waveguide diffraction grating 2015
Is formed on a quartz substrate, it is possible to oscillate at a stable frequency even with temperature fluctuations.

In a conventional mode-locked laser,
It was difficult to set the pulse width. However, in the configuration of the present embodiment, the pulse width is controlled by controlling the number of output waveguides 75 of the arrayed waveguide grating 15 and the reflectance of the high reflection mirror 2021, that is, by setting the oscillation spectrum width. Can be set in advance. For example, a Gaussian envelope spectrum as shown in FIG. 60 can be realized. At this time, the pulse waveform on the time axis also becomes Gaussian.

(Embodiment 21) FIG. 61 shows Embodiment 21 of the present invention. The apparatus of this embodiment is a short pulse light source.

The basic structure is the same as that of the twentieth embodiment shown in FIG. Here, the arrayed waveguide diffraction grating 2
15 shows an enlarged view of a slab waveguide 74 and an output waveguide 75 portion.

The feature of this embodiment is that the length of each waveguide of the output waveguide 75 is changed so that dispersion in the optical resonator can be compensated.

Generally, the semiconductor material has a large dispersion, and it is considered that most of the dispersion in the optical resonator of the present invention is a material dispersion of the semiconductor in the optical modulator 2011 and the optical amplification medium 2013. The magnitude of this variance is
It is about 0.005 ps / nm. In the case where the output waveguides 75 are arranged at 50 μm intervals with respect to the array waveguide 73 having a linear dispersion of 1 μm / GHz, if the difference between adjacent waveguide lengths is 0.4 μm, the inside of the optical resonator can be reduced. It is possible to compensate for dispersion. However, for each waveguide length, the phase difference in the resonator for each mode is mπ (m = 0, 1, 2,...)
Is fine-tuned so that

Therefore, the difference between adjacent waveguide lengths may be set as follows.

[0324]

[Equation 19]

Here, λ _K is the wavelength of the K-th mode, n
_eff is the effective refractive index of the output waveguide. Thereby, a pulse close to the transform limit can be generated. When the arrayed waveguide grating 2015 having a large free spectrum range is used, a sub-picosecond ultra-short pulse train can be generated.

(Embodiment 22) FIG. 62A shows Embodiment 22 of the present invention, and the device of this embodiment is a short pulse light source.

The basic structure of this embodiment is the same as that of the twentieth embodiment shown in FIG. Here, an enlarged view of the output waveguide 75 portion of the arrayed waveguide diffraction grating 2015 in Embodiment 20 is shown.

The feature of this embodiment is that a liquid crystal spatial modulator having a lens array and a high-reflection mirror on one side is disposed instead of the high-reflection mirror 2021 on the end face of the output waveguide 75. The lens array is composed of distributed index lenses 2022 arranged at intervals of Δx. The liquid crystal spatial modulator includes a polarizing plate 2023, a glass substrate 2024-
1. Twisted nematic liquid crystal 20 sandwiched between transparent electrode 2025 and alignment film 2026 arranged at intervals of Δx
27, high reflection mirror 2028, glass substrate 2024-2
Are laminated. A low-reflection coating 2029 is applied to both ends of the output waveguide 75, the distributed index lens 2022, and the polarizing plate 2023.

The liquid crystal spatial modulator is provided with a transparent electrode 20 facing the liquid crystal.
By applying a voltage between the mirrors 25,
The reflectance from 28 to the output waveguide 75 can be controlled. As a result, the mode can be dynamically controlled, and the pulse waveform can be changed as needed.

The spatial modulator in this case is not limited to the liquid crystal spatial modulator described above, but may be another modulator such as an MQW modulator, a modulator using the Franz-Keldysh effect, an LN modulator, or a modulator using an optical nonlinear material. Can be used.

In order to perform intra-cavity dispersion compensation, it goes without saying that the above-described phase filter for dispersion compensation may be used. FIG. 62B shows a cross-sectional configuration in this case. In the figure, reference numeral 74 denotes a slab waveguide, 2024 denotes a holding substrate, 2028 denotes a high reflection mirror, and 3000 denotes a dispersion compensation phase filter.

Embodiment 23 FIG. 63 shows Embodiment 23 of the present invention (short pulse light source).

The basic structure of this embodiment is the same as that of the twentieth embodiment shown in FIG. Here, an enlarged view of the slab waveguide 74 and the output waveguide 75 of the arrayed waveguide diffraction grating 2015 is shown.

This embodiment is characterized in that the high reflection mirror 20
Instead of using 21, a diffraction grating 2030 is formed in the output waveguide 75. This diffraction grating 203
0 can function as a very narrow band high-reflection mirror and has spectral characteristics, so that the mode wavelength can be set very precisely. Further, the diffraction grating 20
By arranging the 30s at appropriate positions, dispersion compensation in the optical resonator becomes possible as in the twenty-first embodiment, and a pulse close to the transform limit can be generated.

Embodiment 24 FIG. 64 shows Embodiment 24 of the present invention (short pulse light source).

The basic structure of this embodiment is the same as that of the twentieth embodiment shown in FIG. Here, an enlarged view of the slab waveguide 74 and the output waveguide 75 of the arrayed waveguide diffraction grating 2015 is shown.

The feature of this embodiment is that two or more waveguides of the output waveguide 75 on which the diffraction grating 2030 is formed as in the twenty-third embodiment are connected to the optical multiplexer 2031. . By coupling light from a predetermined waveguide of the output waveguide 75 by the optical multiplexer 2031,
By combining predetermined modes in the case of mode-lock oscillation, various pulse waveforms can be generated. For example, if only odd-numbered or even-numbered modes are combined and output, an optical short pulse train having a repetition frequency twice as high as the mode-lock frequency can be generated.

(Embodiment 25) FIG. 65 shows Embodiment 25 of the present invention (short pulse light source).

In the figure, the arrayed waveguide diffraction grating 203
2 is the arrayed waveguide diffraction grating 2 in Embodiment 20.
In this configuration, the output waveguide 75 is omitted from 015, and a plurality of high reflection mirrors 2021 are arranged on the focal plane of the slab waveguide 74 at intervals of Δx. Other configurations are the same as those of the twentieth embodiment.

FIG. 66 shows an arrayed waveguide diffraction grating 2032.
Is an enlarged view of the slab waveguide 74 of FIG.

In the figure, the arrayed waveguide diffraction grating 203
The end face of the second substrate 70 is cut along the focal plane of the slab waveguide 74, and a plurality of high reflection mirrors 2021 are arranged on the end face at intervals of Δx. In addition, high reflection mirror 2
In order to reduce end surface reflection from portions other than 021, a low reflection coating is applied to the entire end surface of the substrate 70.

(Embodiment 26) FIG. 67 shows Embodiment 26 of the present invention (short pulse light source).

The basic configuration of the twenty-sixth embodiment is shown in FIG.
This is the same as Embodiment 25 shown in FIG. Here, an enlarged view of the slab waveguide 74 portion of the arrayed waveguide diffraction grating 2032 is shown.

This embodiment is characterized in that the high reflection mirror 20
Instead of using 21, a diffraction grating 2033 is formed on the focal plane of the slab waveguide 74.

[0345] This diffraction grating 2033 can be written using ultraviolet rays, similarly to the diffraction grating formed in the optical fiber. In a quartz substrate, since the coupling constant of the diffraction grating is small and the loss is small, the diffraction grating 2033 can function as a very narrow band high reflection mirror. Further, since the high reflection mirror formed by the diffraction grating 2033 in the slab waveguide 74 has a spectral characteristic in addition to the spectral function of the arrayed waveguide diffraction grating 2032, the mode wavelength can be set very precisely. Also, by displacing each position of the diffraction grating 2033 on the normal to the focal plane, dispersion compensation in the optical resonator becomes possible as in the twenty-first embodiment, and a pulse close to the transform limit is generated. can do.

(Embodiment 27) FIG. 68 shows Embodiment 27 of the present invention (short pulse light source).

The basic structure is the same as that of the embodiment 26 shown in FIG. Here, the arrayed waveguide diffraction grating 2
An enlarged view of a portion 032 of the slab waveguide 74 is shown. Fig. 68
(A) is a plan view, and FIG. 68 (B) is a cross-sectional view along the line AA ′ in FIG. 68 (A). Reference numeral 76 denotes a waveguide core.

This embodiment is characterized in that the high reflection mirror 20
Instead of using 21, a groove 2034 perpendicular to the substrate 70 is formed along the focal plane of the slab waveguide 74, and a polyimide film 2036 on which a plurality of mirrors 2035 are formed is inserted into the groove. is there.

The polyimide film 2036 is made of an adhesive 2 which is transparent at the operating wavelength and has a small refractive index difference from the equivalent refractive index of the waveguide in order to remove unnecessary reflected light from the end face of the waveguide.
Fixed at 037. In addition, polyimide film 203
In order to remove the reflected light from the part without the mirror 2035, a low reflection coating 2038 is applied to the surface. In order to avoid reflection from the back surface, a light absorbing film 2039 is laminated on the back surface side. In this embodiment, various films other than the polyimide film can be used. In addition, the said Embodiment Example 21-27
Although the arrayed waveguide grating in the above is set for a short pulse light source, the arrayed waveguide grating in these embodiments can be applied to other applications such as waveform shaping and dispersion compensation.

(Embodiment 28) FIG. 69 shows Embodiment 28 of the present invention (short pulse light source).

In this embodiment, a configuration in which the optical modulator 2011 and the optical amplifying medium 2013 are integrated is shown. n-InP
An MQW layer for light modulation 2041, i-In
P etch stop layer 2042, laser MQW layer 204
3, n-InP layer 2044, n-InGaAsP layer 20
45, an AuZnNi electrode 2046 is laminated, and n-InP
An AuGeNi electrode 2047 is attached to the back surface of the layer 2040. A high reflection mirror 20 is provided on the end face on the side of the optical modulator 2011.
48 (2019), a low-reflection coating 2049 is applied to the end surface on the optical amplification medium 2013 side. Such integration reduces the number of components of the short pulse light source, and requires only one optical coupling means between the arrayed waveguide gratings 2015 and 2032, so that an economical and highly reliable short pulse light source can be used. Can be realized.

(Embodiment 29) Referring to FIG.
Reference numeral 01 denotes a fiber output type optical modulator in which a low reflection structure is provided on the output surface and a high reflection structure is provided on the opposite end surface. Reference numeral 2102 denotes a modulator driving circuit, 2103 denotes a fiber output type optical amplification medium, and 2104. Is an amplification medium excitation circuit, 210
5 is a four-terminal optical circulator, 2106 is a non-reflection terminator, 2107 is an optical coupler, 2108 is a polarization maintaining optical fiber, 2109 is an arrayed waveguide diffraction grating, 2110 is an optical waveguide, 2111 is a first slab waveguide. , 2112 is a waveguide array, 2113 is a second slab waveguide, 211
4 is a lens, 2115 is a high reflection mirror, and 2116 is a fine movement table.

FIG. 71 is an enlarged view of the high reflection mirror 2115 of FIG. FIG. 71A is a plan view, FIG.
(B) is an end view. Here, 2117 is a quartz substrate,
2118 is a point reflection coating, 2119 is Au / Cr
Etc. are high reflection mirrors. The width of each mirror 2119 is constant, and the distance between adjacent mirrors changes in the y direction in FIG. 71 (A).

FIG. 72 is a layout diagram showing the vicinity of the high reflection mirror 2115. In the figure, reference numeral 2120 denotes a lens substrate, and 2114 denotes a lens. The mirror 2115 is arranged so that a certain surface thereof coincides with the image forming surface. In this figure, the direction perpendicular to the paper surface is the y direction, and the rotation angle around the y axis is θ. The fine movement table 2116 connected to the mirror 2115 enables fine movement in the x, y and θ directions. In this embodiment, by moving the mirror 2115 in the x direction, it is possible to control the center frequency during mode-lock oscillation and the oscillation frequency of each mode. By moving in the y direction, the interval between the mirrors 2119 changes, so that the mode interval, that is, the pulse repetition period can be controlled. Further, the θ direction is controlled so that the mode locked state is easily generated, and the delay time in the resonator is set to be an integral multiple or a fraction of the pulse repetition period.

The twenty-ninth embodiment has a feature that the repetition period and the center frequency of the pulse train can be easily controlled. In the drawings, each component of the optical fiber is shown to be connected, but it is needless to say that it may be connected by a lens as in the other embodiments. Also, in other embodiments, it is needless to say that the connection is made by an optical fiber as in the present embodiment.

Embodiment 30 FIG. 73A shows Embodiment 30 of the present invention. This embodiment relates to an optical signal processing apparatus capable of observing a real-time waveform of an optical signal. .

In FIG. 73A, reference numeral 3101 denotes a signal light incidence waveguide for making signal light incident. 310
Reference numeral 2 denotes a first slab waveguide, which has a function of distributing the output light of the signal light incident waveguide 3101 to the array waveguide 3103. The array waveguide 3103 converts the incident signal light into time-
It has a function to perform spatial conversion.

Reference numeral 3104 denotes a reference light incidence waveguide for allowing reference light to enter. Reference numeral 3105 denotes a first slab waveguide for reference light, which is an input waveguide 310 for reference light.
4 has a function of distributing the output light to the array waveguide 3106. The array waveguide 3106 has a function of performing time-space conversion of the incident reference light.

[0359] Reference numeral 3107 denotes a second slab waveguide, which has a function of performing Fourier transform on output lights output from the array waveguides 3103 and 3106, respectively.
Reference numeral 3108 denotes a photodetector diode (PD) array. The interference between the signal light Fourier-transformed by the second slab waveguide 3107 and the reference light results in the second slab waveguide 3PD.
The electric field intensity distribution of the Fourier transform hologram formed on the focal plane 107 is detected. 3109 is a PD array 310
8 is an optical signal restoring circuit for restoring the signal light input from the electric field intensity distribution of the Fourier transform hologram detected by 8. Also, 200 is the waveguide 3101, 310
4. An arrayed waveguide diffraction grating composed of slab waveguides 3102, 3105, 4107 and arrayed waveguides 3103, 3106.

Here, when the signal light is time-space converted by the array waveguides 3103 and 3106, if the spatial axes are inverted with respect to the time axis, no hologram can be obtained. Wave path 3103
3106 is bent in the same direction as shown in FIG. 73 (A), whereby the signs of the spatial axis with respect to the time axis are aligned on the emission surface of the arrayed waveguide.

In the thirtieth embodiment, the PD array 3108 is almost in close contact with the focal plane of the second slab waveguide 3107, but a lens is further provided on the focal plane of the second slab waveguide 107. Phase compensation may be performed. When designing two waveguide arrays, as shown in FIG. 73, the signal light array waveguide 3103 is on the exit side, and the reference light array waveguide 3106 is on the incidence side thereof, about 1 cm each. The addition of a straight array waveguide prevents the array waveguides from overlapping each other.

FIG. 73B shows a structure having equivalent functions. Figure 73
In (B), reference numeral 3110 denotes a second slab waveguide for reference light, and 3111 denotes a half mirror. The half mirror 3111 is formed by forming a groove in a substrate using a dicing saw after forming a waveguide, and inserting the groove into the groove. The position of the half mirror 3111 is determined so that the reference light incident on the slab waveguide 3110 is reflected by the half mirror 3111 and forms an image on the focal plane of the slab waveguide 3107.
At this time, in order to form an off-axis hologram, the optical axis of the reference light needs to form an angle of about 3 to 30 degrees with respect to the optical axis of the signal light. The smaller the angle between the signal light and the reference light is, the better the resolution is. However, in order to separate the signal light and the reference light, as shown in FIG. It must be large enough so that the beams do not overlap.

The waveguide in FIG. 73A was formed as follows as an example. First, a lower clad layer and a core layer are sequentially deposited as a glass fine particle film on a single crystal silicon substrate by a flame hydrolysis volumetric method (FHD method), and then heated to a high temperature in an annealing furnace. A transparent glass film to cover. Thereafter, patterning is performed in the shape of a waveguide, and unnecessary core layers are removed using dry etching. Then, the upper cladding layer is deposited again using the FHD method, and heated to a high temperature to make the upper cladding layer transparent. Let it. In Embodiment 30 of the present invention, such a manufacturing method is used, but a semiconductor layer such as InP is formed of InG as a core layer.
It is clear that a semiconductor waveguide structure manufactured by epitaxially growing a semiconductor having a higher refractive index than the cladding such as aAsP, patterning and etching, and then re-growing InP as an upper cladding layer again has the same function. is there. In this case, it is desirable that the material is transparent in a wavelength range to be used.

FIG. 73D shows a detailed view of the photodetector diode array used in this embodiment. The size of one photodetector diode in a 256 one-dimensional array is 200 μm in length and 30 μm in width, and each pixel is arranged at a period of 50 μm. The charge generated in each pixel is stored in the charge integrator 3114. The accumulated charge is read out by sequentially operating pixels by a CMOS shift register 3115. Further, the optical signal restoration circuit 3109 includes an electronic computer and a program for performing a mathematical operation described later on the distribution of the hologram interference fringes detected by the light detection diode array,
It comprises a display device for displaying the restored electric field distribution of the original optical signal.

FIG. 73D shows a detailed view of the photodetector diode array used in this embodiment. The size of one photodetector diode in a 256 one-dimensional array is 200 μm in length and 30 μm in width, and each pixel is arranged at a period of 50 μm. The charge generated in each pixel is stored in the charge integrator 3114. The accumulated charge is read out by sequentially operating pixels by a CMOS shift register 3115.

The optical signal restoration circuit 3109 is provided with an electronic computer and a program for performing a mathematical operation to be described later on the distribution of the hologram interference fringes detected by the light detection diode array, and an electric field of the restored original optical signal. It comprises a display device for displaying the distribution.

The signal light s to be observed in the waveguide 3101
1 (t) is incident, and the known reference light r
When 1 (t) is incident, the signal light and the reference light undergo time-space conversion at the emission ends of the respective arrayed waveguides 3103 and 3106, when the coordinate axis is x1, and
They are converted to s2 (x1) and r2 (x1), respectively. These optical signals s2 (x1) and r2 (x1) are Fourier-transformed by diffraction when propagating through the slab waveguide 107. On the focal plane of the slab waveguide 3107, the signal light and the reference light are converted into spatial frequencies in the focal plane coordinates. If the axis is ξ, they are converted to S (ξ) and R (ξ), respectively. Where S (ξ) and R (ξ) are s2 (x
1), Fourier transform of r2 (x1). At the focal plane of the slab waveguide 3107, S (ξ) and R (ξ) interfere with each other to form a hologram. When the electric field intensity distribution G (ξ) of this hologram is expressed by a mathematical formula,

[0368]

(Equation 20)

[0369]

(Equation 21)

The following can be derived. Although not explicitly shown in the above equation (12), here, in the slab waveguide 3107,
Since the signal light s2 (x1) and the reference light r2 (x1) are incident from different positions, this is a configuration equivalent to the off-axis method in the holographic technique.

Therefore, each term appearing in the above equation (12),

[0372]

(Equation 22)

Correspond to the 0th-order, + 1st-order, and -1st-order diffraction components, respectively, and have different diffraction directions. Therefore, in the optical signal restoration circuit 3109, it is possible to derive the electric field component S (分離) to be observed by separating it on a mathematical expression.

In addition, actually, the second slab waveguide 31
Although the focal plane of 07 is arc-shaped, in this embodiment,
It is cut on a straight line near the focal plane, and the focal plane and the cut plane do not exactly match. That is, the signal light that has been subjected to the time-space change is not a strict Fourier transform image on the straight section plane. For this reason, when reproducing the original signal waveform from the interference fringes of the hologram received by the light detection diode array 3108, an error occurs at the time of performing the inverse Fourier transform.

In the present embodiment, as a method for solving such a problem that an error occurs, the second slab waveguide 31 is used.
The correction was performed by attaching a Fresnel lens that compensates for dispersion due to a phase shift to the cut surface of the 07, but if the waveform of the signal light is reproduced by calculation as described above without using the Fresnel lens, the In the process of calculating the diffraction, that is, in the process of performing the inverse Fourier transform, by using a more general diffraction formula, not using the Fourier transform, compensating for the dispersion due to the phase shift, and calculating the diffracted light , Can be corrected.

Also, in practice, the second slab waveguide 31
Although the focal plane of 07 is arc-shaped, in this embodiment,
It is cut on a straight line near the focal plane, and the focal plane and the cut plane do not exactly match. That is, the signal light that has been subjected to the time-space change is not a strict Fourier transform image on the straight section plane. For this reason, when reproducing the original signal waveform from the interference fringes of the hologram received by the light detection diode array 3108, an error occurs at the time of performing the inverse Fourier transform.

In this embodiment, as a method for solving such a problem that an error occurs, the second slab waveguide 31 is used.
The correction was performed by attaching a Fresnel lens that compensates for dispersion due to a phase shift to the cut surface of the 07, but if the waveform of the signal light is reproduced by calculation as described above without using the Fresnel lens, the In the process of calculating the diffraction, that is, in the process of performing the inverse Fourier transform, by using a more general diffraction formula, not using the Fourier transform, compensating for the dispersion due to the phase shift, and calculating the diffracted light , Can be corrected. Actually, using the optical system shown in FIG.
A set of 13 pulse trains with a pulse interval of about 4.2 ps
Incident from the signal light incident waveguide 3101 as signal light,
Single-pulse light having a pulse width of 1 ps and being close to transform limited is used as a reference light incident waveguide 3104 as reference light.
It was confirmed that the electric field distribution of the incident signal light pulse train can be mathematically restored from the electric field intensity distribution of the Fourier transform hologram when the light is incident from the.

Embodiment 31 FIG. 74 shows Embodiment 31 of the present invention, and relates to an optical signal processing device capable of observing a waveform. In FIG. 74, reference numeral 3201 denotes a diffraction grating, which has a function of performing time-space conversion of the incident signal light 3204 and the incident reference light 3205. Reference numeral 3202 denotes a lens, which has a function of performing Fourier transform on the signal light diffracted by the diffraction grating 3201 and the reference light. Reference numeral 3203 denotes a photodetector diode (PD) array, which is arranged in the vicinity of the focal plane of the lens 3202, and includes a Fourier transform hologram formed on the focal plane of the lens 3202 by interference between the Fourier transformed signal light and the reference light. Detect the electric field strength distribution.
Reference numeral 3206 denotes an optical signal restoration circuit for restoring the input signal light from the electric field intensity distribution of the Fourier transform hologram detected by the PD array 3203. Example 3 of the embodiment
As in the case of 0, it is possible to derive a signal light from the off-axis Fourier transform hologram by mathematical operation.

An optical system as shown in FIG. 74 is actually arranged on an optical surface plate, and an appropriate modulation is applied to this optical system to a train of 100 pulses having a pulse width of 0.3 ps and a pulse interval of about 8.3 ps. Inject the added random signal, pulse width 0.1p
It was confirmed that the electric field distribution of the incident pulse signal can be mathematically restored from the electric field intensity distribution of the Fourier transform hologram when a single pulse close to s transform-limited is incident as the reference light.

[0380]

As described above, according to the present invention,
Generation of 1-10ps optical pulse, waveform shaping, waveform measurement,
An optical signal processing device and an optical signal processing method capable of performing waveform recording, correlation processing, and the like can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an example of a conventional optical signal processing device.

FIG. 2 is a diagram showing pulse intensities of an incident optical signal and an output signal in a conventional device.

FIG. 3 is a diagram showing a relationship among an optical spectrum of an incident optical signal, a spatial filter transmittance of the optical signal, and an optical spectrum of an output optical signal in the conventional device.

FIG. 4 is a configuration diagram of a mode-locked laser used as a conventional short pulse light source.

FIG. 5 is a configuration diagram of a conventional multi-wavelength light source that simultaneously oscillates light of many wavelengths.

FIG. 6 is a configuration diagram of a conventional optical signal processing device capable of dispersion compensation.

FIG. 7 is a configuration diagram of another conventional optical signal processing apparatus capable of dispersion compensation.

FIG. 8 shows the first embodiment of the present invention, and is a configuration diagram of an optical signal processing device of the present invention.

FIG. 9 shows the first embodiment of the present invention, and is another configuration diagram of the optical signal processing device of the present invention.

FIG. 10 shows a first embodiment of the present invention, and is a further configuration diagram of the optical signal processing device of the present invention.

FIG. 11 shows a second embodiment of the present invention, and is a configuration diagram of an optical signal processing device of the present invention.

FIG. 12 is a configuration diagram showing a modified example of the optical signal processing device according to the second embodiment of the present invention.

FIG. 13 is a configuration diagram illustrating another modified example of the optical signal processing device according to the second embodiment of the present invention.

FIG. 14 shows a third embodiment of the present invention, and is a configuration diagram of an optical signal processing device of the present invention.

FIG. 15A is a configuration diagram of a waveguide array part of an optical signal processing device according to a third embodiment of the present invention, and FIG.
FIG. 3 is an enlarged view of a star coupler portion of the optical signal processing device shown in FIG.

FIG. 16 is a diagram for explaining a fourth embodiment of the present invention, and is a diagram showing a pulse waveform of light incident on an optical signal processing device of the present embodiment.

FIG. 17 is a view for explaining a fourth embodiment of the present invention and is a diagram showing a pulse waveform of light emitted to an optical signal processing device of the present embodiment.

FIG. 18 is a view for explaining a fourth embodiment of the present invention and is a diagram showing a pulse waveform of light emitted to an optical signal processing device of the present embodiment.

FIG. 19 is a diagram showing the relationship between the respective light pulse widths to be handled and the maximum number of light pulses that can be processed when the device according to the fourth embodiment of the present invention and the conventional device are used.

FIG. 20 shows a fifth embodiment of the present invention, and is a configuration diagram of an optical signal processing device of the present invention.

FIG. 21A is an enlarged cross-sectional view of a Fresnel lens portion of an optical signal processing device according to a fifth embodiment of the present invention, and FIG. 21B is an optical signal processing device according to a fifth embodiment of the present invention. FIG. 2 is a plan view of a Fresnel lens.

FIG. 22 is a diagram illustrating pulse intensities of an incident optical signal and an output signal in the optical signal processing device according to the fifth embodiment of the present invention.

FIG. 23 is a diagram illustrating a relationship between an optical spectrum of an incident optical signal, a relative position of a phase filter, and an optical spectrum of an output optical signal in the optical signal processing device according to the fifth embodiment of the present invention.

FIG. 24A is an enlarged sectional view of a Fresnel lens part of a modification of the optical signal processing device according to the fifth embodiment of the present invention;
(B) is an enlarged sectional view of a Fresnel lens part of another modification of the optical signal processing device according to the fifth embodiment of the present invention, and (C).
Is an enlarged sectional view of a Fresnel lens part of still another modification of the optical signal processing device according to the fifth embodiment of the present invention, and (D).
FIG. 14E is an enlarged cross-sectional view of a Fresnel lens part of still another modification of the optical signal processing device according to the fifth embodiment of the present invention, and FIG.
FIG. 14 is an enlarged cross-sectional view of a Fresnel lens portion of still another modification of the optical signal processing device according to the fifth embodiment of the present invention.

FIG. 25 (A) shows a sixth embodiment of the present invention, and is a cross-sectional configuration view of a spatial filter portion composed of liquid crystal of the optical signal processing device of the present invention, and FIG. 25 (B) is a sixth embodiment of the present invention. FIG. 3 is a plan view of a transparent electrode constituting a spatial filter of the optical signal processing device according to the embodiment.

FIG. 26A shows a seventh embodiment of the present invention, and is a plan view of the vicinity of an exit of a slab waveguide of an optical signal processing device of the present invention, and FIG. 26B is a seventh embodiment of the present invention. FIG. 4 is a cross-sectional configuration diagram near an exit of a slab waveguide of the optical signal processing device according to the embodiment.

FIG. 27 is a configuration diagram of an optical signal processing device according to an eighth embodiment of the present invention.

FIG. 28 is an enlarged cross-sectional view near a spatial filter provided in a central portion of an optical signal processing device according to an eighth embodiment of the present invention.

FIG. 29A shows a modified example of the optical signal processing device according to the eighth embodiment of the present invention, and is an enlarged cross-sectional view near the spatial filter of the device, and FIG. FIG. 13 shows another modification of the optical signal processing device according to the embodiment of the present invention, in which an enlarged cross-sectional view near the spatial filter of the device is shown.
An optical signal processing apparatus according to another embodiment of the present invention is a modification of the embodiment, an enlarged cross-sectional view near the spatial filter of the apparatus,
(D) shows still another modified example of the optical signal processing device according to the eighth embodiment of the present invention, and is an enlarged sectional view near the spatial filter of the device.

FIG. 30 is a configuration diagram of an optical signal processing device according to a ninth embodiment of the present invention.

FIG. 31 is an enlarged configuration diagram of an arrayed waveguide of an optical signal processing device according to a ninth embodiment of the present invention.

FIG. 32 is a configuration diagram of an optical signal processing device according to a tenth embodiment of the present invention.

FIG. 33 is a configuration diagram of an optical signal processing device according to an eleventh embodiment of the present invention.

FIG. 34 is a configuration diagram of an optical signal processing device according to a twelfth embodiment of the present invention.

FIG. 35 is a configuration diagram of an optical signal processing device according to a thirteenth embodiment of the present invention.

FIG. 36 is a cross-sectional configuration diagram near a Fresnel lens of an optical signal processing device according to a thirteenth embodiment of the present invention.

FIG. 37 (A) is a top view of a spatial filter of the optical signal processing device according to the thirteenth embodiment of the present invention, and FIG. 37 (B) is a spatial filter of the optical signal processing device according to the thirteenth embodiment of the present invention; FIG.

38A is a longitudinal sectional view of a Fresnel lens of an optical signal processing device according to a thirteenth embodiment of the present invention, and FIG. 38B is a Fresnel lens of the optical signal processing device according to the thirteenth embodiment of the present invention. (C) is a cross-sectional view of a Fresnel lens of an optical signal processing device according to a thirteenth embodiment of the present invention.

FIG. 39 illustrates a P used in a spatial filter and a Fresnel lens of an optical signal processing device according to a thirteenth embodiment of the present invention.
FIG. 4 is a diagram showing the exposure dependency of the development depth of MGI.

FIG. 40 is a sectional view of a Fresnel lens formed by etching a quartz substrate using PMGI as a mask in the optical signal processing device according to the thirteenth embodiment of the present invention.

FIG. 41 is a diagram illustrating filter characteristics (positive dispersion) of the optical signal processing device according to the thirteenth embodiment of the present invention.

FIG. 42 is a diagram illustrating filter characteristics (negative dispersion) of the optical signal processing device according to the thirteenth embodiment of the present invention.

FIG. 43 is a configuration diagram of an optical signal processing device according to a fifteenth embodiment of the present invention.

FIG. 44 shows a sixteenth embodiment of the present invention.
1 is a block diagram of an optical signal processing device in a broad sense according to the present invention.

FIG. 45 is a time waveform of the output light intensity of the modulator of the optical signal processing device according to the sixteenth embodiment of the present invention, and the output waveform after transmission through the optical signal processing device which is one of the components of the device. FIG.

FIG. 46 is a diagram illustrating characteristics of a phase filter (using a third-order or higher-order term) in a case where the device of the thirteenth embodiment is used as an optical signal processing device of a component in the sixteenth embodiment of the present invention. It is.

FIG. 47 is a diagram illustrating characteristics of a phase filter (a completely random phase change) when the device of the thirteenth embodiment is used as an optical signal processing device of a component in the sixteenth embodiment of the present invention. .

FIG. 48 is a diagram illustrating characteristics of an intensity filter in a case where a filter that reduces only the vicinity of the center frequency is used as an intensity filter of the optical signal processing device on the receiving side of the components in the sixteenth embodiment of the present invention. is there.

FIG. 49A is a diagram showing characteristics of a phase filter of an optical signal processing device according to a seventeenth embodiment of the present invention in the case of a reflection type configuration, and FIG. 49B is a diagram showing a seventeenth embodiment of the present invention; FIG. 4 is a diagram illustrating characteristics of a phase filter of the optical signal processing device of the reflection type configuration.

FIG. 50A is a diagram showing a frequency spectrum amplitude of an intensity modulation signal in a seventeenth embodiment of the present invention;
(B) is a figure which shows the frequency spectrum amplitude of an angle modulation signal in the 17th Embodiment of this invention.

FIG. 51 is a configuration diagram of an optical signal processing device according to an eighteenth embodiment of the present invention.

FIG. 52 is a diagram showing an average light intensity distribution on a filter plane in an eighteenth embodiment of the present invention.

FIG. 53 is a diagram illustrating a modulated signal, a signal after phase modulation, and a demodulated signal after reproduction according to an eighteenth embodiment of the present invention.
It is a figure showing each waveform.

FIG. 54 is a configuration diagram of an optical signal processing device according to a nineteenth embodiment of the present invention.

FIG. 55 is a configuration diagram of an optical signal processing device (short pulse light source) according to a twentieth embodiment of the present invention.

FIG. 56 shows the frequency of light incident on the slab waveguide 72 and the slab waveguide 7 in the twentieth embodiment of the present invention.
FIG. 4 is a diagram illustrating a relationship of an imaging position x on a focal plane No. 4;

FIG. 57 is a diagram showing a reflection spectrum when the interval Δx between the output waveguides 75 is 50 μm and the core width is 10 μm in the twentieth embodiment of the present invention.

FIG. 58 is a diagram showing an oscillation wavelength spectrum of the optical signal processing device according to the twentieth embodiment of the present invention.

FIG. 59 is a diagram showing the oscillation pulse wavelength of the optical signal processing device according to the twentieth embodiment of the present invention.

FIG. 60 is a diagram showing an example of an oscillation wavelength spectrum that can be realized by the optical signal processing device according to the twentieth embodiment of the present invention.

FIG. 61 is an enlarged view of a main part of an optical signal processing device (short pulse light source) according to a twenty-first embodiment of the present invention.

FIG. 62A is an enlarged view of a main part of an optical signal processing device (short pulse light source) according to a twenty-second embodiment of the present invention, and FIG. 62B is an optical signal according to the twenty-second embodiment of the present invention; FIG. 3 is a configuration diagram near a phase filter used for performing dispersion compensation in a resonator in a processing device (short pulse light source).

FIG. 63 is an enlarged view of a main part of an optical signal processing device (short pulse light source) according to a twenty-third embodiment of the present invention.

FIG. 64 is an enlarged view of a main part of an optical signal processing device (short pulse light source) according to a twenty-fourth embodiment of the present invention.

FIG. 65 is a configuration diagram of an optical signal processing device (short pulse light source) according to a twenty-fifth embodiment of the present invention.

FIG. 66 is an enlarged view of a main part of the device shown in FIG. 65.

FIG. 67 is an enlarged view of a main part of an optical signal processing device (short pulse light source) according to a twenty-sixth embodiment of the present invention.

FIG. 68A is an enlarged view of a main part of an optical signal processing device (short pulse light source) according to a twenty-seventh embodiment of the present invention, and FIG. 68B is a cross section taken along line AA ′ of FIG. FIG.

FIG. 69 is a sectional view showing an optical signal processing device (short pulse light source) according to a twenty-eighth embodiment of the present invention.

FIG. 70 is a configuration diagram of an optical signal processing device according to a twenty-ninth embodiment of the present invention.

FIG. 71 (A) is a plan view of a high reflection mirror of an optical signal processing device according to a twenty-ninth embodiment of the present invention, and FIG. 71 (B) is an optical signal processing device according to a twenty-ninth embodiment of the present invention. FIG. 3 is a cross-sectional configuration diagram of a high reflection mirror portion.

FIG. 72 is a diagram showing an arrangement near a high reflection mirror of an optical signal processing device according to a twenty-ninth embodiment of the present invention.

73A is a configuration diagram of an optical signal processing device according to a thirtieth embodiment of the present invention, and FIG. 73B is a configuration diagram of a modification of the optical signal processing device according to the thirtieth embodiment of the present invention; (C) is an enlarged view of a main part of the configuration shown in (B), and (D) is a configuration diagram of a photodetector diode array used in the optical signal processing device according to the thirtieth embodiment of the present invention.

FIG. 74 is a configuration diagram of an optical signal processing device according to a thirty-first embodiment of the present invention.

[Explanation of symbols]

1 Quartz Waveguide 2, 10, 14, 25, 36, 42, 57 Star Coupler 3, 11, 15, 24, 32, 43, 58 Waveguide Array 4, 12, 16, 23, 34, 35, 59 Slab Conductor Wave path 5, 17, 109 Spatial filter 6, 52 Optical connector 7 Optical fiber 8 Quartz optical circuit 9, 13, 22, 26, 33, 37, 41, 56 Optical waveguide 18 Half-wave plate 19, 53, 120, 122, 502 , 1017,10
19, 1021, 1032, 1039 Optical amplifier 20 Spatial filter control device 21 Reflection type computer hologram (CGH) 31 Transmission type computer hologram 51 Optical recording medium 54 Optical coupler 55 Quartz optical circuit 60 Optical modulator 61 Reference waveguide 101 , 111 quartz substrate 102 optical circulator 103 optical fiber 104, 507, 804, 902 optical waveguide 105, 504, 211, 3102 first slab waveguide 106, 601, 802, 3103, 3106 array waveguide 107, 506, 2113 3107 Second slab waveguide 108 Fresnel lens 109a, 116 Phase filter 109b Intensity filter 110, 402, 2035 Mirror 101A First quartz substrate 101B Second quartz substrate 112 Low reflection filter 113 Holding substrate 1 4 Pattern mirror 115, 2114, 3202 Lens 121, 906 Optical filter 200 Array waveguide diffraction grating 200A First array waveguide diffraction grating 200B Second array waveguide diffraction grating 301a, 301b Transparent electrode 302 Alignment film 303 Spacer 304 Nematic Liquid crystal 305 Quarter wave plate 401 Optical waveguide core 403 Diagonal (7-8 degree) end face groove 501 Heat sink 503 Filter control device 505 Second array waveguide 602 Heating electrode 603 Wiring 604 Control device 605 In waveguide Provided groove 606 Waveguide taper structure for reducing connection loss 607 波長 wavelength plate 701 Reference light input waveguide 702 Slab waveguide 703 as second distribution means 703 Second array waveguide 704 Optical recording medium 801 Second imaging means Slab waveguide 803 Slab waveguide 901 which is a multiplexing means 901 Monochromatic CW light source 903 Slab waveguide 904 Optical receiver array 905 Parallel-serial conversion circuit 1001 Light source 1002, 2011 Optical modulator 1003 Optical modulation signal generation circuit 1004 From thirteenth Any one of the optical signal processing devices 1005, 1020, and 1040 shown in the fifteenth embodiment 1006 One of the optical signal processing devices shown in the thirteenth to fifteenth embodiments 1007 Optical receivers 1011 and 1031 Short Pulse light sources 1013, 1022, 1033, 1041 Optical wavelength filters 1014, 1023, 1034, 1042 Optical branching elements 1015, 1035 n optical modulation circuits 1016, 1024 n optical circulators 1017 n input waveguides 1018 optical coupling Wave element 1025 n units 1036, 1037, 109, 1044, 1045, 1
049 Transmission optical signal processing device 1038 Optical multiplexing element 1046 n optical receiving circuits 2012 Drive circuit 2013, 2103 Optical amplification medium 2014 Excitation circuit 2015, 2032, 2109 Array waveguide diffraction grating 2016, 2017 Optical coupling means 2018, 2020, 2028, 2038, 2049
Low reflection coating 2019, 2021, 2048, 2115 High reflection mirror 2020 Distributed index lens 2023 Polarizing plate 2024 Holding substrate 2024-1, 2024-2 Glass substrate 2025 Transparent electrode 2026 Alignment film 2027 Twisted nematic liquid crystal 2029 Reflection coating 2030, 2033 , 3201 diffraction grating 2031 optical multiplexer 2034 groove perpendicular to substrate 2036 polyimide film 2039 light absorption film 2040 n-InP substrate 2041 MQW layer for light modulation 2042 i-InP etch stop layer 2043 MQW layer for laser 2044 n-InP Layer 2045 n-InGaAsP layer 2046 AuZnNi electrode 2047 AuGeNi electrode 2102 Modulator drive circuit 2104 Amplification medium excitation circuit 2105 4 terminals Type optical circulator 2106 Non-reflection terminator 2107 Optical coupler 2108 Polarization-maintaining optical fiber 2110 Optical waveguide 2112 Waveguide array 2116,2116 Fine adjustment table 2117 Quartz substrate 2118 Point reflection coating 2119 High reflection mirror such as Au / Cr 2120 Lens substrate 2115 , 2119 Mirror 3000 Dispersion Compensation Phase Filter 3101 Signal Light Incident Waveguide for Injecting Signal Light 3104 Reference Light Incident Waveguide for Injecting Reference Light 3105 First Slab Waveguide for Reference Light 3108, 3203 Photodetector diode (PD) array 3109, 3206 Optical signal restoration circuit for restoring input signal light from electric field intensity distribution of Fourier transform hologram detected by PD array 3110 Second slab waveguide for reference light 311 Half mirror 3114 charge integrator 3115 CMOS shift register 3204 incident signal light 3205 incident reference beam

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03H 1/02 G03H 1/02 G06E 3/00 G06E 3/00 G11C 13/04 G11C 13/04 Z (31) Claim number of priority Patent application Hei 9-58877 (32) Priority date Hei 9 (1997) March 13 (33) Priority claiming country Japan (JP) (31) Priority claim number Patent application Hei 9-179469 (32) Priority date 9 (1997) July 4 (33) Priority claim country Japan (JP) (31) Priority claim number Japanese Patent Application No. 9-199704 (32) Priority date Hei 9 (1997) July 25 (33) Priority Claiming country Japan (JP) (72) Inventor Kazunori Naganuma 3-19-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Within Japan Telegraph and Telephone Corporation (72) Inventor Hirokazu Takenouchi 3-192 Nishi-Shinjuku, Shinjuku-ku, Tokyo No. Nippon Telegraph and Telephone Corporation (72) Inventor Tetsuyoshi Ishii Nishi-Shinjuku, Shinjuku-ku, Tokyo Eye # 19 No. 2, Nippon Telegraph and Telephone Corporation in the

Claims (88)

[Claims] 1. An optical waveguide comprising: an optical waveguide; first means for equally dividing output light of the optical waveguide; and an assembly of optical waveguides whose optical path lengths change at regular intervals. A waveguide array; second means for imaging the optical output of the waveguide array; and a mirror for receiving the light imaged by the second means and reflecting the incident light. Optical signal processing device. 2. An optical waveguide comprising: an optical waveguide; first means for equally dividing the output light of the optical waveguide; and an aggregate of optical waveguides whose optical path lengths change at regular intervals. A waveguide array; second means for imaging the optical output of the waveguide array; receiving the light imaged by the second means, distributing the incident light on a straight line, and An optical signal processing device comprising: a spatial filter that modulates and reflects a desired intensity or phase according to the position of the light. 3. An assembly of a first optical waveguide, first means for equally dividing output light of the first optical waveguide, and an optical waveguide whose optical path length changes at regular intervals, A first waveguide array that splits output light, a second unit that forms an image of the optical output of the first waveguide array, and an incident light that receives the light that is imaged by the second unit. A spatial filter that distributes light on a straight line and modulates and transmits the light to a desired intensity according to the position on the straight line, and a set of optical waveguides whose optical path lengths are changed at regular intervals by the light modulated by the spatial filter. A third means for entering a second waveguide array made of a body, the second waveguide array, and a fourth means for converging output light of the second waveguide array to one point.
And a second optical waveguide into which the output light of the fourth means is incident. 4. An optical signal input to an optical signal processing device having a waveguide array grating and a spatial filter converts the optical signal into a frequency spectrum image. And modulating the frequency spectrum image to a single point to obtain a new optical signal. 5. The optical signal processing method according to claim 4, wherein the optical signal processing device is the optical signal processing device according to claim 2 or 3. 6. A reflection type spatial filter, a waveguide array comprising an aggregate of optical waveguides whose optical path lengths change at regular intervals, and a coherent light input to the reflection type spatial filter and the reflection type spatial filter. An optical signal comprising: first means for inputting the coherent light modulated by a spatial filter into the waveguide array; and second means for converging output light from the waveguide array to one point. Processing equipment. 7. A transmission type spatial filter, a waveguide array including an aggregate of optical waveguides whose optical path lengths change at regular intervals, a first means for inputting coherent light to the transmission type spatial filter, A second means for injecting the coherent light modulated by the transmission type spatial filter into the waveguide array; and a third means for converging output light from the waveguide array to one point. Optical signal processing device. 8. Coherent light is input to an optical signal processing device having a waveguide array grating and a spatial filter on which a hologram image corresponding to a frequency spectrum of a desired optical signal is written, so that an optical signal is input. An optical signal processing method characterized by generating the signal. 9. The optical signal processing method according to claim 4, wherein the optical signal processing device is the optical signal processing device according to claim 6. 10. An optical signal processing apparatus according to claim 2, wherein first and second optical waveguides are used in place of the optical waveguide, and an optical recording medium is used in place of said spatial filter. Signal processing device. 11. An optical signal processing apparatus, wherein an optical recording medium is used in place of the spatial filter of the optical signal processing apparatus according to claim 3. 12. The optical recording medium according to claim 10, wherein the optical recording medium is a photorefractive element or a photosensitive film.
Or the optical signal processing device according to 11. 13. An optical signal processing device according to claim 10, wherein an optical signal is input to a first optical waveguide of the device, and is referred to a second optical waveguide of the device. An optical signal processing method, wherein the optical signal is recorded by inputting light. 14. An optical signal processing apparatus according to claim 2, wherein an optical sensor array is used in place of the spatial filter of the optical signal processing apparatus according to claim 2. 15. An optical signal processing method using the optical signal processing device according to claim 14, wherein an optical signal is input to an optical waveguide of the device and an output of the optical sensor array is measured. 16. The method according to claim 2, wherein the diffraction order of the optical waveguide array grating is m, and the value of m is 2 or more. Optical signal processing device. 17. The optical signal processing device according to claim 1, wherein the light that modulates the oscillation light in the optical resonator at the input side of the optical waveguide at a frequency substantially equal to the resonance mode interval or an integer multiple thereof. A modulating unit and an optical amplifying unit are provided; the modulating unit, the amplifying unit, and the optical waveguide are sequentially coupled by an optical coupling unit; and a light reflection mirror is provided on an end surface of the optical modulator that does not face the coupling unit. Provided that the mirror formed on the end face of the second means is of a high reflection type, a resonator is formed between these high reflection mirrors, and short pulse light can be generated. An optical signal processing device. 18. The optical signal processing device according to claim 17, wherein a plurality of output waveguides are provided at a predetermined interval between a focal plane of one slab waveguide of the arrayed waveguide grating and the high reflection mirror. An optical signal processing device, wherein a wave path is arranged. 19. The optical signal processing device according to claim 18, wherein the plurality of output waveguides are arranged at equal intervals. 20. The optical signal processing device according to claim 18, wherein the reflectance of the high reflection mirror corresponding to each output waveguide is different. 21. The optical signal processing device according to claim 18, wherein a predetermined waveguide length difference for compensating dispersion in the optical resonator is set in the plurality of output waveguides. An optical signal processing device characterized by the above-mentioned. 22. The optical signal processing device according to claim 18, wherein the high-reflection mirror is replaced with a high-reflection mirror.
An optical signal processing device comprising: a plurality of lens arrays arranged at predetermined intervals; and a liquid crystal spatial modulator having a high reflection mirror on one surface. 23. The optical signal processing apparatus according to claim 18, wherein a diffraction grating is formed at a predetermined position on each of the plurality of output waveguides instead of the high reflection mirror. Processing equipment. 24. The optical signal processing device according to claim 23, further comprising an optical multiplexer for multiplexing a part or all of the plurality of output waveguides. 25. The optical signal processing apparatus according to claim 23, wherein diffraction efficiencies of diffraction gratings formed in the respective output waveguides are different from each other. 26. The optical signal processing device according to claim 17, wherein a plurality of high reflection mirrors are arranged at predetermined intervals on a focal plane of one slab waveguide of the arrayed waveguide diffraction grating. Optical signal processing device. 27. The optical signal processing device according to claim 26, wherein a plurality of high reflection mirrors are arranged at equal intervals. 28. The optical signal processing device according to claim 26, wherein the plurality of high reflection mirrors have different reflectivities. 29. The optical signal processing apparatus according to claim 26, wherein a plurality of diffraction gratings are formed at predetermined intervals in a focal plane of the slab waveguide instead of the high reflection mirror. Signal processing device. 30. The optical signal processing device according to claim 29, wherein a plurality of diffraction gratings are arranged at equal intervals. 31. The optical signal processing device according to claim 29, wherein a plurality of diffraction gratings have different diffraction efficiencies. 32. The optical signal processing device according to claim 29, wherein each position of the plurality of diffraction gratings is formed by being displaced in a direction normal to a focal plane of the slab waveguide. Optical signal processing device. 33. The optical signal processing device according to claim 26, wherein a groove is formed in the focal plane of the slab waveguide instead of the high reflection mirror, and a plurality of mirrors are stacked at a predetermined interval in the groove. An optical signal processing device comprising a film arranged thereon. 34. The optical signal processing device according to claim 17, wherein the optical signal processing device has a configuration in which an optical modulation unit and an optical amplification unit are integrated. 35. The optical signal processing device according to claim 17, wherein a part of each component is connected by an optical fiber. 36. The optical signal processing device according to claim 17, wherein the position of the high reflection mirror can be controlled by a fine movement mechanism. 37. The optical signal processing device according to claim 17, wherein an interval between the high reflection mirrors changes in a normal direction of the slab waveguide. 38. An optical waveguide, an array waveguide composed of a plurality of optical waveguides having sequentially increasing waveguide lengths, distribution means for distributing output light of the optical waveguide to the array waveguide, and the array waveguide Image forming means for forming an image of the output light, a spatial filter disposed near a focal plane of the image forming means for modulating an image of light, a reflecting means for reflecting light modulated by the spatial filter, An optical signal processing device comprising: a light branching unit for extracting reflected light from the reflection unit in the optical waveguide. 39. A first optical waveguide comprising: a first optical waveguide; and a plurality of optical waveguides whose waveguide lengths are sequentially increased.
An array waveguide, distribution means for distributing the output light of the first optical waveguide to the first array waveguide, and first imaging means for imaging the output light of the first array waveguide A spatial filter arranged near the focal plane of the first imaging means for modulating an image of light, and a second array waveguide composed of a plurality of optical waveguides whose waveguide lengths are sequentially increased. A second imaging means for imaging the light modulated by the spatial filter on the second arrayed waveguide; a second optical waveguide; and multiplexing the output light of the second arrayed waveguide. And a multiplexing means coupled to the second optical waveguide. 40. A first optical waveguide comprising: a first optical waveguide; and a plurality of optical waveguides whose waveguide lengths are sequentially increased.
An array waveguide, distribution means for distributing output light of the first optical waveguide to the first array waveguide, a reference light incident optical waveguide, and a plurality of optical waveguides whose waveguide lengths are sequentially increased. The second consisting of
An array waveguide, a second distribution unit that distributes output light of the reference light incidence optical waveguide to the second array waveguide, and output light of the first array waveguide and the second array. Imaging means for imaging the output light of the waveguide; an optical recording medium arranged near the focal plane of the imaging means; and a light branching means for extracting the reflected light from the first optical waveguide. An optical signal processing device comprising: 41. A first optical waveguide comprising: a first optical waveguide; and a plurality of optical waveguides whose waveguide lengths are sequentially increased.
An array waveguide, first distribution means for distributing the output light of the first optical waveguide to the first array waveguide, a reference light incidence optical waveguide, and a plurality of waveguides whose waveguide lengths are sequentially increased. Of the third optical waveguide
An array waveguide, a second distribution unit that distributes output light of the reference light incident optical waveguide to the third array waveguide, and output light of the first array waveguide and the third array waveguide. A first imaging means for imaging the output light of the wave path; an optical recording medium disposed near a focal plane of the first imaging means; and a plurality of optical waveguides whose waveguide lengths are sequentially increased. Second
An array waveguide, a second imaging unit that images light modulated by the optical recording medium on the second array waveguide, a second optical waveguide, and an output of the second array waveguide. Multiplexing means for multiplexing light and coupling the multiplexed light to the second optical waveguide. 42. A first optical waveguide comprising: a first optical waveguide; and a plurality of optical waveguides whose waveguide lengths are sequentially increased.
An array waveguide, first distribution means for distributing the output light of the first optical waveguide to the first array waveguide, a first reference light incidence optical waveguide, and a waveguide having a sequentially longer length. The second consisting of a plurality of optical waveguides
An array waveguide, a second distribution unit that distributes output light of the first reference light incident optical waveguide to the second array waveguide, a second reference light incident optical waveguide, A first imaging means for imaging the output light of the first array waveguide, the output light of the second array waveguide, and the output light of the second reference light incidence optical waveguide; An optical recording medium arranged near the focal plane of the imaging means; a second imaging means for imaging light modulated by the optical recording medium; and an optical recording medium arranged near the focal plane of the second imaging means. An optical signal processing device comprising: a light receiving array; 43. An optical signal processing apparatus according to claim 38, wherein said imaging means is a slab waveguide having a circumferential end face. 44. An optical signal processing apparatus according to claim 38, wherein said image forming means comprises a slab waveguide and a phase spatial modulation element. apparatus. 45. The optical signal processing device according to claim 38, wherein the spatial filter is a phase filter. 46. The optical signal processing device according to claim 38, wherein the spatial filter is an intensity filter. 47. The optical signal processing device according to claim 38, wherein the spatial filter is a spatial filter in which an intensity filter and a phase filter are connected in multiple stages. 48. The optical signal processing device according to claim 43, wherein a focal length of said phase spatial modulation element is equal to a focal length of a slab waveguide of said coupling means. 49. The optical signal processing apparatus according to claim 38, wherein the spatial filter and the reflection means are combined to form a pattern mirror composed of a number of partial mirrors. 50. The optical signal processing device according to claim 38, wherein the spatial filter is a spatial filter that also functions as a phase spatial modulation element. 51. The optical signal processing device according to claim 38, wherein said image forming means is a lens. 52. The optical signal processing apparatus according to claim 38, wherein the imaging means is a slab waveguide on a focal plane, and a phase adjustment array waveguide is provided at an end of the slab waveguide. An optical signal processing device, wherein a wave path end is connected to the spatial filter. 53. The optical signal processing apparatus according to claim 52, wherein the imaging means is a slab waveguide on a focal plane, and a phase adjustment array waveguide is provided at an end of the slab waveguide. An optical signal processing device comprising an optical modulator array. 54. The optical signal processing device according to claim 52, wherein a phase difference between the waveguides of the phase adjustment array waveguide is an integral multiple of 2π. 55. The optical signal processing device according to claim 38, wherein said optical branching means is an optical circulator. 56. The optical signal processing device according to claim 38, wherein the imaging means is a slab waveguide, and a light bending means for bending light in a direction perpendicular to the waveguide at an end of the slab waveguide. An optical signal processing device comprising: 57. The optical signal processing device according to claim 38, wherein the spatial filter is a glass substrate,
An optical signal processing device comprising a liquid crystal spatial modulator comprising a transparent electrode, a liquid crystal, and a liquid crystal alignment film. 58. The optical signal processing apparatus according to claim 57, further comprising a quarter-wave plate in the liquid crystal spatial modulator. 59. The optical signal processing device according to claim 57, wherein the liquid crystal of the liquid crystal spatial modulator is a twisted nematic type. 60. An optical signal processing method using the optical signal processing device according to claim 38, wherein a time-series optical signal is input to the optical waveguide, whereby the time-series optical signal is input to the optical waveguide. Converting the optical signal into a frequency spectrum image, applying a desired phase and / or intensity modulation to the frequency spectrum image by the spatial filter, and combining the modulated light to obtain a new time-series optical signal. Optical signal processing method. 61. An optical signal processing method using the optical signal processing device according to claim 38, wherein a filter characteristic of the spatial filter corresponds to a frequency spectrum of a desired time-series optical signal. An optical signal processing method, wherein a desired optical signal is generated by inputting coherent pulsed light to the optical waveguide, which is a hologram image of a pattern to be formed. 62. Claims 40, 43, 44, 51, 5
57. An optical signal processing method using the optical signal processing device according to any one of items 5 and 56, wherein the signal light is incident on the optical waveguide, and the reference light of coherent pulse light is incident on the reference light input waveguide. A hologram recording, a reference light of another coherent pulse light is incident on the reference light input waveguide, and a phase conjugate light of the signal light is output. 63. An optical signal processing method using the optical signal processing device according to claim 40, wherein signal light is incident on the optical waveguide and coherently incident on the reference light input waveguide. Pulse light reference light is incident, hologram recording is performed on the recording medium, another coherent pulse light reference light is incident on the reference light input waveguide, and signal light or correlation light between the signal light and the reference light is output. An optical signal processing method. 64. An optical signal processing method by the optical signal processing device according to claim 42, wherein the signal light is incident on the optical waveguide, and the first reference light input guide is provided. The reference light of coherent pulse light is incident on the waveguide, the reference light of monochromatic light is incident on the second reference light input waveguide, and a spatial image of the signal light waveform is formed on the photodetector array, and the pulse waveform is observed. An optical signal processing method. 65. A first optical amplifier comprising: a first optical amplifier; an optical wavelength filter; a first optical waveguide; and a plurality of optical waveguides whose waveguide lengths are sequentially increased.
An array waveguide, distribution means for distributing the first optical waveguide output light to the array waveguide, first imaging means for forming an image of the first array waveguide output light, and the first A spatial filter disposed near the focal plane of the imaging means for modulating an image of light, a reflecting means for reflecting the light modulated by the spatial filter, and for extracting the reflected light from the first optical waveguide An optical signal processing apparatus comprising: an optical branching unit of (1) and a second optical amplifier. 66. A first optical amplifier comprising: a first optical amplifier; an optical wavelength filter; a first optical waveguide; and a plurality of optical waveguides whose waveguide lengths are sequentially increased.
An array waveguide, distribution means for distributing the first optical waveguide output light to the array waveguide, first imaging means for forming an image of the first array waveguide output light, and the first A second spatial filter disposed in the vicinity of the focal plane of the imaging means and configured to modulate a light image; and a plurality of optical waveguides whose waveguide lengths are sequentially increased.
An array waveguide, a second imaging means for imaging the light modulated by the spatial filter on the second array waveguide, a second optical waveguide, and the second array waveguide output light An optical signal processing device, comprising: a multiplexing means for multiplexing the second optical waveguide and coupling to the second optical waveguide; and a second optical amplifier. 67. An optical signal processing device comprising: the optical signal processing device according to claim 65; a light source; an optical modulator; and an optical modulation signal generation circuit. 68. An optical signal processing device comprising: the optical signal processing device according to claim 65; and an optical receiver. 69. An optical signal transmission circuit comprising: the optical signal processing device according to claim 65 or 66; a light source; an optical modulator; and an optical modulation signal generation circuit. An optical signal processing device according to
An optical signal processing device comprising: an optical receiver; an optical signal receiving circuit including the optical receiver; and an optical transmission line. 70. The optical signal processing device according to claim 65, wherein the spatial filter is a phase filter, and the relative phase φ is relative to a position (x) on the spatial filter, φ (x) = Mod [ax ² , Π] (a: a constant). 71. The optical signal processing device according to claim 66, wherein the spatial filter is a phase filter, and a relative phase φ is a position (x) on the spatial filter, and φ (x) = Mod [ax ² , 2π] (a: constant). 72. The optical signal processing device according to claim 65, wherein the spatial filter is a phase filter, and the relative phase φ is relative to the position (x) on the spatial filter, φ (x) = π / 2 ( x> 0) and φ (x) = 0 (x <
0) or φ (x) = 0 (x> 0) and φ (x) = π / 2 (x <
An optical signal processing device which performs intensity modulation-angle modulation conversion having characteristics approximating 0). 73. The optical signal processing device according to claim 66, wherein the spatial filter is a phase filter, and the relative phase φ is relative to a position (x) on the spatial filter, φ (x) = π (x> 0) and φ (x) = 0 (x <0),
Alternatively, an optical signal processing apparatus that performs intensity modulation-angle modulation conversion having characteristics approximating φ (x) = 0 (x> 0) and φ (x) = π (x <0). 74. The optical signal processing device according to claim 65, wherein the spatial filter comprises a phase filter and an intensity filter. 75. The optical signal processing device according to claim 65, wherein the spatial filter is a liquid crystal spatial modulator including a glass substrate, a transparent electrode, a liquid crystal, and a liquid crystal alignment film. Optical signal processing device. 76. The optical signal processing device according to claim 69, wherein the frequency spectrum phase of the optical signal generated by the optical signal transmission circuit is modulated, and the dispersion in the optical fiber is performed by the optical reception circuit. And compensating frequency spectrum phase modulation by the optical signal transmission circuit. 77. The optical signal processing device according to claim 69, wherein the frequency spectrum intensity of the optical signal generated by the optical signal transmission circuit is modulated, and the dispersion in the optical fiber is modulated by the optical reception circuit. And compensating frequency spectrum intensity modulation by the optical signal transmission circuit. 78. The optical signal processing apparatus according to claim 69, wherein a frequency spectrum phase and a frequency spectrum intensity of an optical signal generated by the optical signal transmitting circuit are modulated, and the optical fiber is transmitted to the optical receiving circuit. An optical signal processing method comprising compensating for dispersion in the medium and frequency spectrum phase modulation and frequency spectrum intensity modulation by the optical signal transmission circuit. 79. A short-pulse light source, a first optical amplifier, a first optical wavelength filter, and a first branch for branching output light of the first optical wavelength filter into n (integer) light beams. Means, a first n optical modulation circuits, a first n input / output optical waveguides, and a first optical waveguide comprising a plurality of optical waveguides whose waveguide lengths are sequentially increased.
An array waveguide, first distribution means for distributing the optical waveguide output light of the first n input / output optical waveguides to the first array waveguide, and the first array waveguide output light First imaging means for imaging light, a first spatial filter arranged near the focal plane of the first imaging means for modulating an image of light, and modulated by the first spatial filter. The first that reflects the light
Reflection means; second light branching means for extracting the reflected light from the first n input / output optical waveguides; and multiplexing the reflected lights from the n second light branching means. A first optical signal processing device comprising: a first optical multiplexing unit, a second optical amplifier, an optical transmission line, a third optical amplifier, a second optical wavelength filter, Third branching means for branching the output light of the second optical wavelength filter into n (integer) light beams, second n input / output optical waveguides, and a plurality of waveguides whose waveguide lengths are sequentially increased. A second optical waveguide
An array waveguide, a second distribution unit that distributes the optical waveguide output light of the second input / output optical waveguide to the second array waveguide, and forms an image of the second array waveguide output light. A second image forming means, a second spatial filter arranged near the focal plane of the second image forming means for modulating an image of light, and a light modulated by the second spatial filter. Reflective second
Reflecting means; n fourth optical branching means for extracting the reflected light from the second input / output optical waveguide; and receiving reflected light from the n fourth optical branching means. n
An optical signal processing device comprising: two optical receivers; and a second optical signal processing device comprising: 80. A short-pulse light source, a first optical amplifier, a first optical wavelength filter, and a first branch for branching output light of the first optical wavelength filter into n (integer) light beams. Means, a first n optical modulation circuits, a first n input / output optical waveguides, and a first optical waveguide comprising a plurality of optical waveguides whose waveguide lengths are sequentially increased.
An array waveguide, a first distribution unit that distributes the optical waveguide output light of the first input / output optical waveguide to the first array waveguide, and forms an image of the first array waveguide output light. A first image forming means, a first spatial filter arranged near a focal plane of the first image forming means for modulating a light image, and a plurality of optical waveguides having a sequentially increased waveguide length The second consisting of
An array waveguide, a second imaging unit that images light modulated by the first spatial filter on the second array waveguide, a first n output optical waveguides, The output light of the second array waveguide is multiplexed to form the first n
A first optical multiplexing means for coupling to the output optical waveguides, a second optical multiplexing means for multiplexing the outputs of the first n output optical waveguides, and a second optical amplifier. A first optical signal processing device, an optical transmission line, a third optical amplifier, a second optical wavelength filter, and output light of the second optical wavelength filter is converted into n (integer) lights. A third branching means for branching; a second n input / output optical waveguides; and a third optical waveguide comprising a plurality of optical waveguides whose waveguide lengths are sequentially increased.
An array waveguide, a second distribution unit that distributes the optical waveguide output light of the second input / output optical waveguide to the third array waveguide, and forms an image of the third array waveguide output light. A third spatial filter arranged in the vicinity of the focal plane of the third imaging means, for modulating a light image, and a plurality of optical waveguides whose waveguide lengths are sequentially increased. The fourth consisting of
An array waveguide, a fourth imaging means for imaging light modulated by the second spatial filter on the fourth array waveguide, a second n output optical waveguides, The output light of the fourth array waveguide is multiplexed to form the second n
A second optical signal processing device comprising: third optical coupling means coupled to the output optical waveguide; and n optical receivers for receiving output light from the second output optical waveguide. An optical signal processing device comprising: 81. First time-space conversion means for converting a time-series optical signal of signal light into spatial signal light, and second time-space conversion for converting a time-series optical signal of reference light into spatial signal light Means, imaging means for forming spatial signal lights respectively output from the first time-space conversion means and the second time-space conversion means and causing them to interfere with each other, and a focal point of the imaging means A light receiving unit that is arranged near a surface and receives an interference light image of a plurality of optical signals incident on the imaging unit; and an optical signal restoration circuit that restores a time-series signal of the signal light from a detection signal of the light receiving unit. An optical signal processing device comprising: 82. The optical signal processing device according to claim 81, wherein said first and second time-space conversion means are constituted by an arrayed waveguide grating, and said imaging means is a Fourier transform of said space signal light. An optical signal processing device comprising a slab waveguide having a function of performing 83. The optical signal processing apparatus according to claim 81, wherein said first and second time-space converting means are constituted by diffraction gratings, and said image forming means performs a Fourier transform of said spatial signal light. An optical signal processing device comprising: 84. The optical signal processing device according to claim 81, wherein said light receiving means comprises a photodiode array. 85. The optical signal processing device according to any one of claims 81 to 84, wherein the optical signal restoring circuit calculates the intensity of the incident signal light from an electric field intensity distribution of a Fourier transform hologram detected by the light receiving unit. An optical signal processing device for restoring an electric field distribution of an optical pulse by arithmetic processing. 86. A step of converting a time-series optical signal of an unknown signal light into a spatial signal light; a step of converting a time-series optical signal of a known reference light into a spatial signal light; Forming a hologram image of a pattern corresponding to a frequency spectrum of a time-series signal on a focal plane by forming spatial signals of the reference light and causing the spatial signals to interfere with each other; An optical signal processing method, comprising: converting the signal light into a signal; and restoring the unknown signal light from the hologram image converted into the electric signal using a predetermined arithmetic expression. 87. The optical signal processing method according to claim 86, wherein the step of restoring the unknown signal light from the hologram image includes an electric field distribution of a reference light known in the hologram image formed on the focal plane. 1. An optical signal processing method comprising: a mathematical operation for multiplying an electric field distribution of a reproduction light mathematically derived from a mathematical operation, followed by a Fourier transform operation and a space-time transform operation. 88. The optical signal processing method according to claim 87, wherein the electric field distribution of the reproduction light on the focal plane multiplied by the hologram image is the amplitude of the electric field distribution of the input known reference light on the focal plane. An optical signal processing method comprising a factor divided by a square of an absolute value of a distribution.