JP2695740B2 - All-optical regenerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the processing of digital information in the form of optical signals applicable to fields such as fiber optic communication and information transmission systems, body optics and computer engineering circuits. More particularly, the present invention relates to an all-optical semiconductor device capable of reproducing, amplifying, and switching an optical signal.

[0002]

2. Description of the Related Art A clock circuit, a pulse reshuffling (pulse reshuff) without an electronic stage in the middle.
aping), elements for all optical elements that perform the same function as signal amplification have been increased. One method for realizing an all-optical regenerator is a system having a simple configuration in which only optical signals are present in all signal processing stages and high-speed execution is performed, and is preferably implemented using a semiconductor device. Is to configure. In the last decade, there has been a gradual development in this direction.

An example of such a conventional apparatus is disclosed in 1983, Appl. Phys. Lett, Vol. 43, No. 4, 339 by Tsang.
-Mode-locked Semiconductor on page 341
Lasers With Gateable Output and Electrically Contr
ollable Optical Absorber. This device consists of three coupled laser diodes for generating a mode-locked semiconductor laser. In this device, the first laser diode is used as a light source. The saturable abso together with the electrically controllable optical obsorber adopted
forming a laser that generates a mode-locked light pulse with ber). Since the third diode can be electrically controlled, it acts as an electronic shield to provide a mode-locked semiconductor laser that can code information into picosecond (ps) light pulse outputs. However, the problem of controlling the output hinders such an apparatus from performing completely opcal processing. Also, the utility of this device is questionable as it is essentially a laboratory device that uses external gratings for active modelocking.

[0004] Other devices that can select a clock frequency using a multi-electrode semiconductor laser are described by M. Jinno and others.
"All-Optical Timing Extraction Using a 1.59μm Se
LF-pulsating Multielectrode DFB LD ", which was proposed in EL, Left. Vol. 24, No. 23, pp. 1426-1427 (1988). The device described therein is optical injection-locking. ) Can synchronize the output light pulse to the clock frequency under the influence of the input pulse in a device that operates under the conditions described in item 2. However, this device also cannot amplify the signal and cannot reproduce the shape of the signal. It is not a pulse (signal) regenerator.

[0005] Other types of devices devised for use include those by M. Jinno and T. Nasumoto.
"All-Optical Timing Extraction Using Optical Tank
A ring resonator (vibrator) or Fabry-Perot (Fabry-Perot) for adjusting a constant frequency, as described in the 100'89 Tecnical Pigest Bulletin Vol.4, pages 96-97 under the title "Ci-rcuits" ) Including an interferometer, and the resonator takes one round trip time (roundtrip tran).
A pulse having a period corresponding to the sit time is generated.
However, such a device is not a resonator of an optical signal because the information signal cannot be reshaped with the shape and amplitude of the optical signal.

One of the more recent well-known systems is the use of two self-electro-optic devices.
It is based on ffect devices (SEED) and detects signals with 2dB optical gain, such as clock recovery, data timing (timing) and signal clocking (signal clocking). Although the SEED can perform various functions of optical signal processing, the SEED is grounded through a parallel LC circuit. "All-Optic-alRegenera" such as CRGiles
tor "(El, Left.) Vol. 24, No. 24, pp. 848-850 (1988), but from a practical point of view, such a device with such electrical elements and the like Such a device is not desirable as an all-optical heyday.
Furthermore, due to the low response speed of SEED itself, no improvement in the bit rate of recoverable data can be expected from such devices. In such devices, it has been warned that a data bit rate of about 5 kilobits / second has been achieved. Moreover, this device cannot generate an output signal having a desired shape and / or pulse width.

[0007] From a technical point of view, the prior art device closest to the present invention is disclosed in US Pat. No. 5,001,523 issued March 19, 1991, entitled "Optical Transistor". The "optical transistor" is used to control and amplify an optical signal as well as to select radiation of many frequencies depending on a channel or the like.

The advantages of such a device are that the device has a high amplification factor and can be designed to be compact if it can control optical signals. In addition, a resonator having a high quality factor can be used by using a resonance ring as an integrated optical device.

However, this device has defects. These defects have no elements for generating various clock frequencies, and do not synchronize the output optical signal with the clock frequency. Including that it cannot be played back.

[0010]

SUMMARY OF THE INVENTION Accordingly, it is a primary object of the present invention to provide a so-called all-optical regenerator in which optical signals are present in all optical processing stages, wherein the all-optical regenerator is provided with an input light. Performs various optical signal processing functions, such as generating an optical signal having predetermined parameters that define the shape and amplitude of the optical signal, and synchronize the output optical signal to a clock frequency. Let it.

[0011]

According to the present invention, there is provided at least one or more waveguides, a non-linear ring resonator and a directional coupler, wherein the one or more waveguides are respectively input and output optical contacts. Wherein the nonlinear ring resonator is coupled to each of the at least one waveguide, and each of the directional couplers is coupled to the nonlinear ring resonator and each of the at least one or more waveguides. And means for adjusting optical coupling therebetween, wherein the non-linear ring resonator comprises: a source laser acting as a source of optical radiation; a multi-source laser generating a clock frequency; Forming a cavity for the laser and the multi-section laser, each of the interfaces and the like between the two lasers and a portion of the nonlinear ring resonator adjacent to the laser and the like. A provided mirror; a plurality of phase modulators provided between the two lasers and the directional coupler for synchronizing an output optical signal to the clock frequency; and the source laser; An all-optical regenerator comprising a section laser and means for controlling the multi-phase modulator.

The apparatus of the present invention is disclosed in US Pat.
It exhibits special and significantly superior properties that are distinguished from any known prior art, including the device disclosed in U.S. Pat. Some examples for these properties are as follows.

(1) Generation of an output signal having a predetermined or desired pulse width and magnitude.

This is achieved according to the invention by the operation of a multi-section semiconductor laser and a phase modulator forming a single (common) resonator.

(2) Generation of clock frequency.

Such performance is due to a multi-section semiconductor laser operating with a saturable absorber in mode clocking conditions.

(3) Synchronization of the output optical signal with the clock frequency.

Such a result is obtained because, according to the invention, the light emission of the multisection semiconductor laser is coupled to a common (single) optical field of the ring resonator and controlled by this phase modulator. You.

(4) A tuning range of 6 to 10 nm (tunig ra)
nge) The generation and emission of a clock frequency optical signal at a fixed frequency.

Such flexibility is obtained by controlling the current flowing in the cells of the multi-section semiconductor laser.

The above and other advantages of the device according to the present invention are realized by using components constituting a regenerator and the like. In particular, directional couplers chose radiation from the channel (IEEE Journal of Quantum Elec
Rod C. Alferness's "Guided Wave Device for O" published in tronics, Vol. 17, No. 6, pp. 945-957 (1981).
ptical Comm-unication ") and have a bistable mode with positive feedback (" Bistable Op. "disclosed in French Patent No. 2464498 published on 1981.3.1).
The optical feedback of the device of the present invention is accomplished by using a non-linear ring resonator. Thus, the directional coupler is essentially a means of amplifying the optical signal where an optical bistable mode is inherent. Configure one stage (VMAnd-re
ev, VAVerbitsky, SALoneshevitch, "Optical Blsta
ble Swiching Divice ", Communication Equipment Seri
es: "Wire Communication Engineering, Vol. 6, 116-121
Page).

The directional coupler of the device is adjusted to minimize the coupling coefficient under normal conditions (no input optical signal). When an input signal is applied, such coupling forms a non-linear directional coupler with a band-shaped waveguide. It is amplified by the nonlinear characteristics of the nonlinear ring resonator.

The increase in light intensity in the nonlinear ring resonator relative to the directional coupler results in increased pumping in the bistable nonlinear ring resonator. That is, such a unique characteristic is the upper position shown in FIG.
Further, the transition of the switch-on state is further accelerated. In this case, optical coupling is amplified by changes in the refractive index (the refractive index in the coupling waveguide determines the coefficient and length of the coupling). The result is self supporting and is accelerated in the direction of increasing light intensity in the nonlinear ring resonator.

It is well known that injection semiconductor lasers act as a source of light radiation and can be used to increase the intensity of the optical signal generated through one of the mirrors of these resonators. (Optical and Qu
antum Electronics, 21, Special Ampli-fiers, pp S-S25,
1989).

The response of the nonlinear resonator is shifted such that the index of refraction n of the nonlinear phase modulator is converted and the nonlinear ring resonator approaches the resonance condition, thereby increasing the light emission intensity within the nonlinear ring resonator. It has the characteristic that the system is brought into a resonance condition by repeating the equation in which the refractive index of the phase modulator is increased.

Due to such resonance conditions, the optical system that changes in the order described above gradually goes to the upper position (K
h, Gibbs, Opticl Bistability, translated from Englis
Ed. By FVKarpus-hko, 1988.).

In the initial detuning state of the resonator,
Differential amplification of the generated optical signal is realized. The amplification coefficient is determined by the slope of the characteristic curve 2 shown in FIG. The amplification factor is 10 ⁴ for a bistable system as shown experimentally (F. Tooley atal., "High Gain Signa
l Amplification in an InSb Transphasor at 77K ", App
1, Phys. Lett. 43, No. 9, pp. 807-809. (1983)). The difference amplification which characterizes the present apparatus is performed three times as follows. (1) By applying a signal to the nonlinear ring resonator,
A directional coupler bistable device with optical feedback through the non-linear ring resonator; (2) coupling radiation of the input signal with the clock frequency in the modulator and resonance adjustment of the non-linear ring resonator
and (3) when a signal is output from the nonlinear ring resonator,
Further, it is performed by a directional coupler.

The nonlinear ring resonator has a resonance characteristic with respect to the wavelength λ, and λ can be determined by the following equation.

L = k (λ / 2) (where k is a constant; L is the length of the resonator) Such a resonator that provides the optical feedback of the laser is the resonator of the entire system and is shown in FIG. It is controlled and readjusted with the aid of a phase modulator formed in a non-linear ring resonator waveguide provided below the control electrode 6 shown.

Therefore, the coupling between the radiation from the source laser and the multi-section semiconductor laser and the functional elements of the overall system and the directional coupler is controlled by the nonlinear ring resonator and the parameters of the phase modulator. It can be changed and controlled. This control is performed through the electrode 6 located on the nonlinear ring resonator.

A multi-section semiconductor laser operating in mode-locked state with a saturable absorber is periodic, with a pulse width of a fraction of a PS to hundreds of PS, And a continuous light pulse is obtained. Such an analogy is given by ISGoldobin in 1985 Qantum Electronics, Vol. 12, No. 5,
"Control of Generation" published on pages 983-985
Spiking Mode of Two-component Heterolaser "and H. Kawa
guchi et al., 1987 Electron Lett, Vol. 23,
"Tunable Optical Wavel" on pages 1088-1090
length Conversion Using a Multi-electrode DFB LB wi
th Saturable Absorber. The reciprocation time of a light pulse generated by a multiple semiconductor laser is determined by the formula 2L ₁ / c.

(L ₁ : resonator length of semiconductor laser. C)
Is gigahertz applicable to semiconductor lasers
Accordingly, the integration of a multi-section semiconductor laser and a directional coupler into a single-signal (shared) self-aligned system involves the radiation of the input signal and the radiation of the semiconductor laser. It is assumed that the light emission of the conventional and multi-section semiconductor lasers can be spatially coupled to a single element, namely the resonant ring of a non-linear ring resonator. In this resonator, light radiation is output and transmitted to light output contacts III and IX, for example, as shown in FIG.

In this case, the output optical signal or the like is generated at a preset or desired amplitude and pulse width, and the amplification is generated by an optical bistable effect.

The synchronization of the output optical signal with the clock frequency is performed by a phase modulator, which is activated only when the input and the clock frequency signal are supplied in a synchronized manner.

The nonlinear ring resonator is an external resonator for the source laser and the multi-section semiconductor laser, and can further set a single frequency mode for generating an output optical signal. "Guided-Wave O" edited by T.Tamir
ptoeiectronics, Springer-Velag, Vol. 26, 270-272
See "Mode-controlled Semiconductor Lasers" by IPKaminov, RSTucker, page 1988.

Electrodes that change the refractive index of the photoelectric medium by changing the voltage are widely used with the Δβ key. 1979 "Theory and Experiment on Coupled-wave by K. Tada and others
Gude Optical Modulators with Schottky Contacts ",
Japan J. Appl. Phys. Vol. 18, No. 1, pp. 393-398 (1979).

In the device of the present invention, the electrodes provided on the non-linear ring resonator perform re-tuning of the clock frequency, and as a result, tune the frequency of the output light.

The electrodes of the directional coupler perform the function of adjusting the degree of optical coupling between the linear waveguide and the nonlinear ring resonator.

[0039]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings.

The all-optical regenerator for optical signals according to the present invention is shown in FIG.
This all-optical regenerator includes a non-linear ring resonator 1, a pair of linear waveguides 2 located on both sides of the non-linear resonator, a source semiconductor 3 operating as an optical signal amplifier and a light source, and A multi-section semiconductor 4 is included.

The electrode 5 controls the optical coupling between the waveguide 2 and the ring resonator ₁ by the voltage V _1, and controls the directional coupler 10.
To form

The nonlinear ring resonator 1 tunes and adjusts the characteristics of the output signal by the voltage V ₂ on the electrode 5. Said voltage V ₂ is applied to four separate sections constituting the phase modulator 8. Reference numeral 9 indicates a mirror of the laser 3 and the multi-section semiconductor 4.

Referring to FIG. 2, the output characteristics of the all-optical regenerator described in FIG. 1 are shown with coordinates i representing the light emission in the phase modulator 8 and I representing the output light emission. The characteristics of the bistable optical device are shown by the dotted lines. Curve 1
Shows the characteristic of the differential amplification, and curve 2 shows the characteristic of the optical transistor employed in the present invention.

The optical bistability is evident from the fact that the medium has a critical value of the light emission In (incident light emission), so that the light intensity in the medium increases due to the effects of ternary feedback.

The characteristic of output light-input light, that is, Iout = f
(Iin) (Iin: intensity of light radiation at the input end, Iou
t: the intensity of light emission at the output end)
Or has unstable conditions, and this property is due to the interaction of the light-emitting electromagnetic field with, for example, the atoms of the employed semiconductor medium (D. Miller et al., "Optical Bistability in Sequencing").
miconductors ", IEEE Journal of Quantom Electronic
s, Vol. 17, No. 3, pp. 312-317, (1981)).

At the experimental level, the possibilities and conditions for obtaining a bistable system, etc., have been studied theoretically and experimentally and have two stable "lowers" and "upper". Position value and triode
Mode signal characteristics, that is, optical signal amplification for various materials having non-linearity as exemplified by curve I in FIG. 2, have also been studied (A, Miller, D. Miller, S. Smith).
By "Dynamic Nonlinear Optical Processes in S
emiconductors, Advances in Physics Vol. 30, No. 6
Issue, pages 690-800, (1981)).

Ultra short pulses (eg, sub-ps) of a semiconductor sample can be obtained by mode-locking, ie, by maintaining a constant repetition rate of the laser with a saturable absorber. One of the cells or the like of the multi-section semiconductor laser 4 can act as such an absorber according to a preferred embodiment of the present invention.

Thus, the apparatus may be adapted to generate short, constant and continuous pulses having an adjusted laser pulse width and laser frequency. The pulse width and frequency may be affected by other factors such as the material used, the geometric size, the electrical signal and the voltage applied to the saturable absorber and the radio waves in the active part of the multi-section semiconductor laser. Is done.

The specific method of operating the device shown in FIG. 1 will now be described.

When there is no external input optical signal, the current of the multi-section semiconductor laser 4 or the like is applied to the first section acting as a saturable absorber (I ′ ₂ <0) and the injection of the other two sections. current has further a larger value than the critical value, i.e., I _"2 and I"_2> made of I _th (Figure 1), so that these two sections is active sections operating in emission mode Selected. The current value of the source laser 3 is smaller than the critical value.
That is, I ₁ <I _th .

As described above, the intensity of light emission of the phase modulator 8 is adjusted to be equal to or less than the critical value at which the nonlinear effect starts to appear. That is, the nonlinear ring resonator is out of the resonance condition,
Such a condition is shown as the "lower" position on curve 1 of FIG.

When the intensity of the light radiation from the phase mode modulator 8 is greater than the critical value (I _th ), the light radiation increases sharply and the nonlinear ring resonator 1 is tuned to resonate.

In fact, the refractive index of the substance used in the phase modulator is n = n0 + nIr (n0 is the refractive index when there is no light emission, and n2 is the medium nonlinearity coefficient). When dependent on the intensity Ir, the nonlinear ring resonator will have the effect of optical bistability when the intensity of the light emission reaches a threshold and the refractive index changes from a value corresponding to the "low" state,
It will be placed in the "up" position or state (illustrated by curve 1 in FIG. 2). This change is affected by the increase in light intensity resulting from feedback and laser switching. It occurs abruptly due to the clearly defined nature of the ring resonator.

Light emission in the resonator changes the light length nL of the resonator in the direction of resonance. Increasing the optical field inside the resonator will proceed until the resonance has occurred, further shifting the resonance frequency to the frequency of the input magnetic field.

As the light intensity inside the cavity 1 increases, the light field in the semiconductor laser 3 also increases due to light injection, the charge density decreases, and the refractive index in the laser active region increases. Thus, the source laser 3 is switched to the stimulated emission mode, which further increases the intensity of the light field in the system and causes the point of action of the resonator 1 to become a resonance point as shown by the curve in FIG. Conversion
Will be. This corresponds to a typical phototransistor mode (Yu, L. Bystrov. SALomashevitch, Y
1992 "Optical Transistor New" by uVSvetikov
Fuctional Element of Engineering ", Electrical Comm
unication, Vol. 1, pp. 22-25) Therefore, the increase in the optical field strength and the change in the refractive index in the resonator, as shown in FIG. With a critical region and few critical values.

The normal state of the resonator is located in the “bottom”, which will be put in the switched-on state. In this case, the intensity exceeds the critical value inside the resonator only when the clock frequency pulse generated from the multi-section semiconductor laser 4 and the input optical pulse act simultaneously.

FIG. 5 illustrates the path of an input optical signal through inputs I and II. Reference numerals 1, 2, and 10 represent a link resonator, a linear waveguide, and a directional coupler, and are the same as those shown in FIG.

An external input signal i is applied simultaneously to the inputs I and II of the device, for example, using a divider. The optical signal passing through the input I is applied to the nonlinear ring resonator (FIG. 5) through the directional coupler 10,
The mirror 9 (FIG. 1) is applied to the semiconductor laser 3 which is converted into a laser emission mode under the influence of the optical signal.

In order for the device to operate reliably, it is necessary to synchronize an external input pulse with a clock frequency pulse generated by the multi-section semiconductor laser 4.

Accordingly, an input optical signal or the like is also applied to the mirror 9 of the multi-section semiconductor laser 4 through the input II and via the directional coupling 8 to additionally increase the light intensity of the saturable absorber, As shown in FIG. 4c,
Optical mode synchronization is performed by the panel flow applied to the multi-section semiconductor laser 4. FIGS. 4a, 4b and 4c show the process of synchronizing the clock frequency pulse i _T to the sequence (11001) of the input pulse i.

As a result of the synchronization between the clock frequency pulse and the input pulse, the pulse is simultaneously applied to the phase modulator. The cavity of the nonlinear ring resonator will be switched on by the light field if the light radiation intensity applied to the phase modulator exceeds a critical value. Exceeding the critical value occurs when the synchronization condition between the clock frequency pulse and the input pulse is satisfied, that is, when two consecutive pulses are synchronized and applied to the phase modulator 8. In this case, the output pulse generation mode in FIG. 3 corresponds to "Unity" (1). FIG. 3 also illustrates the generation of the output optical signal of the sequence (11001), where I ₀ is optical pumping, i is the input pulse intensity, and i _T
Represents the intensity of the clock frequency pulse.

FIG. 6 illustrates the path of the output optical signal through the output optical contacts III and IV. The remaining reference numerals and the like are the same as those shown in FIG. The optical signal is transmitted from the nonlinear ring resonator 1 through the directional coupler to the output optical contacts II and IV.

The width of the output pulse is the same as the pulse width of the multi-section semiconductor laser. That is, the width of the output pulse is in the range from a fraction of ps to hundreds of ps depending on the non-uniformity of the power supply injected from the cells of the multi-section semiconductor laser 4 and the material and design parameters. Therefore, the selection of the size and material of the semiconductor laser 4 is made strategically in order to obtain the required pulse width of the regenerated output pulse.

The magnitude of the output optical signal I is shown in FIGS.
Is amplified to a value determined by the slope of the linear portion of curve 2 of the phototransistor shown in FIG. The slope of curve 2 is adjusted by the material and design parameters and is preset at the time of manufacture of this device, or by applying a voltage to the phase modulator 8 or by the dependence of the refractive index on the amount of injected charge. The degree can be changed by controlling the radio waves applied to the multi-section semiconductor laser 4 and the source laser 3 (FIG. 1). Therefore, the synchronized input light pulse i and clock frequency pulse i _T (FIG. 3)
Is applied to the phase modulator 8 so that the nonlinear ring resonator 1 causes an avalanche change in the medium in the phase modulator 8 so that the nonlinear resonator 1 has sufficient light intensity to disclose the above-described process. Changes in the optical length and resonant conditions in the medium, resulting in a change in the resonance tuning of the nonlinear ring resonator, a sharp increase in light emission intensity, and a transition of the entire system to the upper condition position.

When the limiting conditions for the non-tuning θ ₀ (non-tuning phase angle of the nonlinear ring resonator 1) and θ ₁ (non-tuning phase angle of the directional coupler 10 in the optical bistability mode) parameters are satisfied, , An optical transistor, ie,
The differential amplification characteristics of the nonlinear ring resonator are realized. (FIG. 3).

During operation in the optical signal amplification mode with the currents I ₁ and I ₂ (ie, I ₂ ′, I ₂ ″ and I ₂ ″ ″) shown in FIG. 1, the intensity I defined in connection with FIG. ₀
Is adjusted corresponding to the operating point of the characteristic curve I = f (i).

The amplified and regenerated pulses of the optical signal are output from the output optical contacts III and IV (FIG. 6) in a narrow spectral region (high resonance sensitivity at the resonance point of the nonlinear ring resonator) in accordance with the clock frequency. To facilitate this process).

III made of three elements (for example, GaAlAs) or four elements (for example, InGaAsP)
-V compound semiconductors and the like are used for manufacturing the device according to the present invention, and the composition of the device is selected according to the wavelength of light. Semiconductor structures such as those described above include liquid epitaxy, gas epitaxy, and molecular beam epitaxy (M
It is grown using epitaxial techniques such as BE) and metal organic chemical vapor deposition (MOCVD). Such techniques and the like are described in the literature and are known to those skilled in the art.

The design and structure of the active cell, etc., of the regenerator can be embodied in any of the ways described above, which cells are inserted into the corresponding etched wells, etc., in the nonlinear ring resonator. You. This insertion is performed by using an indium adhesive.

The following structure and the like are preferably used for manufacturing the present invention.

1. The double heterostructure is used in the source laser 3 and the multisection semiconductor laser 4.

2. A simple structure is achieved by combining a distributed active layer over the entire ring resonator. The formation of such an active layer is performed by growing a heterostructure along a vertical direction. FIG. 7a shows a plan view of the ring resonator, and FIG. 7b shows a cross section along line (AA) of FIG. 7a. Reference numeral 11 shown in FIG. 7a represents a metal contact. FIG. 7b illustrates a band-shaped structure comprising a metal contact 11, a separation layer 12, a buffer layer 13, a waveguide layer 14, an active layer 15, another waveguide layer 16 and a lower contact 17. The definition of the active layer on the plane consists of the ring-shaped contacts of FIG. 7a and the band-shaped structure as shown in FIG. 7b.

Making a narrow active layer in a buried heterostructure as shown in FIG. 8 represents another way to limit the active layer. FIG. 8 shows an n-GaAs connection layer 21 and an n-
AlGaAs protective layer 22, AlGaAs active layer 23, p
-AlGaAs protective layer 24, n-AlGaAs buried layer 2
5, n-GaAs connection layer 26 ohmic contact 27, base layer 2
8 and the Zn diffusion region 29 are shown. These are possible structures without using the mirror 9 of FIG.

3. Realization of ultra-high-speed information transmission is possible through optical communication through an electromagnetic field between active cells and the like. In order to manufacture a device capable of generating an optical signal at a very high speed, it is required to provide a laser mirror or the like in an integrated optical device.

FIG. 9 shows a second structure consisting of an InGaAsP system that can operate in the wavelength range of 1.5 to 1.6 μm. Arrows indicate the direction of light emission, and indicate the base layer 31, the waveguide layer 32, the active layer 33, the other waveguide layer 34, the limiting layer 35, the ohmic contact 36, the separation layer 37, the other ohmic contact 38, And a Bragg grid 39 are shown. Techniques such as liquid epitaxy, MBE, MOCVD, wet etching and holographic lithography are used to make such structures.

Usually, the following parameters are desirably used.

Active area: 60 μm to 250 μm Band-shaped contact width: 2 μm to 5 μm Active layer thickness: 0.3 μm to 0.7 μm Distributed Bragg mirrors are desirably arranged in the space between the active areas. And the size is limited to 300 to 400 μm.

The above-described design can be realized by, for example, the quantum well structure shown in FIG. FIG.
Indicates the structure of a typical quantum well, such as a semiconductor, used in this device, and represents the typical composition, charge density, and thickness of the layers, etc. within that structure.

[0079]

According to the present invention, various advantages are obtained. Some of the advantages are summarized as follows.

1. 1. Reproduction of an optical signal whose duration is prolonged due to distortion in the process of passing along the optical fiber path; 3. Generation of clock frequency pulses and the like and synchronization of the clock signal and the sequence of information signals; 3.6 Ability to operate in a light generator mode within the tuning range of 6-10 nm wavelength; The ability to select the operating mode in the phototransistor mode and to distribute or select the output signal between optical channels and the like.

[Brief description of the drawings]

FIG. 1 is a plan view of an all-optical regenerator according to a preferred embodiment of the present invention.

FIG. 2 is a diagram illustrating a bistability feature of the all-optical regenerator of FIG. 1;

FIG. 3 is a diagram illustrating an operation of signal amplification of the apparatus when an input pulse (11001) and a clock frequency pulse (1111) coincide with each other.

FIG. 4 is a diagram illustrating a procedure for synchronizing a clock frequency pulse with a reclock in accordance with an input optical signal.

FIG. 5: Through a directional coupler shown as a rectangle by a dotted line,
5 is a diagram showing a path of an input optical signal from a waveguide into a nonlinear resonator.

FIG. 6 is a diagram showing a path of an output optical signal generated from a nonlinear ring resonator to optical contacts III and IV of the waveguide 2.

FIG. 7a is an electrical connection wiring diagram for a uniformly distributed active medium. b: sectional view of a typical semiconductor structure used in the present invention.

FIG. 8 shows a double hetero structure of AlGaAs.
(erostructure) FIG.

FIG. 9 is a view showing an integrated optical structure of a main device element provided with a distributed Bregg mirror.

FIG. 10 shows data related to the structure of a quantum well of a typical semiconductor used in the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Non-linear ring resonator 2 A pair of linear waveguides 3 Source laser 4 Multiple section semiconductor laser 5, 6 Electrode 8 Phase modulator 9 Mirror 10 Directional coupler

Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location H04B 10/04 H04B 9/00 L 10/06 10/142 10/152

Claims (10)

(57) [Claims] The invention further comprises at least one waveguide, a non-linear ring resonator, and a directional coupler, the one or more waveguides each having an input and an output optical contact for an optical signal; A ring resonator is coupled to each of the at least one waveguide, and each of the directional couplers is located between the non-linear ring resonator and each of the at least one or more waveguides. Means for adjusting the optical coupling therebetween, the nonlinear ring resonator comprising: a source laser acting as a light radiation source; a mass section laser generating a clock frequency; the source laser and the multi-section laser. , And each is provided with an interface or the like between the two lasers and a portion adjacent to the laser or the like in the nonlinear ring resonator. A plurality of phase modulators provided between the two lasers and the directional coupler for synchronizing an output optical signal to the clock frequency; the source laser, the multi-section laser, and Means for controlling the multi-phase modulator, the all-optical regenerator. 2. The mirrors of the two lasers,
Distributed feedback (dist) formed from a Bragg mirror shape or a Bragg grid shape
2. The all-optical regenerator according to claim 1, wherein the all-optical regenerator is replaced by a ributed feedback) structure. 3. The all-optical device according to claim 1, wherein the means for controlling the source laser, the multi-section laser, and the multi-phase modulator includes means for adjusting current and voltage. Regenerator. 4. The all-optical regenerator according to claim 3, wherein the phase modulator is a non-linear phase modulator. 5. The all-optical regenerator according to claim 4, wherein the two lasers are manufactured from the same or different semiconductor materials. 6. The all-optical regenerator according to claim 5, wherein the multi-section laser has a section acting as a saturable absorber. 7. The all-optical reproduction according to claim 6, wherein two linear waveguides located outside the non-linear ring resonator are provided as a radially opposed relationship of the ring resonator. vessel. 8. The all-optical regenerator according to claim 7, wherein said adjusting means included in said directional coupler includes means for adjusting a power supply and a voltage. 9. The amplification of an optical signal is performed in the directional coupler by optical feedback through the nonlinear ring resonator when the optical signal enters the nonlinear ring resonator, and the optical signal is amplified by the nonlinear ring resonator. 9. The directional coupler according to claim 8, wherein the directional coupler is performed when the optical signal comes out of the non-linear ring resonator when in the resonator. All-optical regenerator as described. 10. The all-optical regenerator according to claim 5, wherein the two lasers have a plurality of quantum well active layers.