JPH11191015A - Optical device and method for processing digital light signal in free space in parallel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical device which processes digital light signals in a free space in parallel. SOLUTION: An optical device including input means 60 and 600 for a digital light signal 6, a means which can perform conversion to (n) digital light signals 1, 2, 3, and 4, a means which can convert beams of (n) digital light signals to beams of (n) digital light signals 111, 112, 113, and 114, and a means which can select previously selected bits out of one time series 7a in the free space in parallel is further equipped with a light means selected by a group including a means capable of correcting the form of a spatial image 7d and an output means for a processed digital light signal 900.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical device and a method for processing digital optical signals in parallel in free space.

[0002]

2. Description of the Related Art With respect to the widespread development of optical communication systems, it is possible to perform various operations on bits constituting digital information of an optical signal at a high speed, and to use recent methods of information transfer (eg, ATM). There is a need for advanced "supercomputers" and devices that are capable of creating network nodes.

[0003]

SUMMARY OF THE INVENTION The present invention has been designed to implement such means and processors.

The devices currently used for processing optical signals are inadequate to manage the ever-increasing transmission rates possible in fiber optic transmission systems. In practice, such devices consist of digital electronic devices that have a limited bandwidth compared to the available optical bandwidth in fiber optic transmission systems based on sequential information processing.

[0005] Furthermore, devices which allow the signal to be held in optical form, such as intensity modulators or phase modulators,
It processes signals under control of a unit stream and is subject to the inherent limitations of electronic devices.

As a result, there remains a great need to take advantage of all of the optical bandwidth available in fiber optic transmission systems and to process the signal purely with optical control signals, thereby overcoming the inherent limitations of electronic devices. is there.

US Pat. No. 5,589,967 is a method and apparatus for forwarding packets in an optical network implementing multiplexing with a synchronous time division system, wherein the packets are transmitted at a given rate. A method and apparatus are described wherein the transmission rate is determined by the line occupancy time.

[0008] European Patent 0 742 660 A
No. 1 describes a signal processor for processing digital signals in the physical domain (eg, light). The symbol flow is directed to different delay branches. The number of delay branches is such that at any given time, the symbols "1" and "0" are available in at least one branch. By controlling the opening and closing of the on / off switch, the symbol value can be changed. Furthermore, no extra light source is required and the processor is transparent, ie the output symbols of the processor have exactly the same physical properties as the input symbols of the processor. Processing of optical signals occurs in series and in guided propagation.

[0009] Boffi P. "Time / Space Optical Converter" (Optics Communication)
s, 123, 473-476, 1996) is 155
Free-propagation time / time to convert a time-coded binary word of an optical communication signal of 0 nm into a corresponding space-coded word /
A spatial complete optical converter is described. The conversion is performed by four optical gates, one for each of the four polarized optical signals. Each optical gate includes first and second indium-doped cadmium tellurium crystals (CdTe: In). One for the first four crystals,
And there are two light control beams, one for each of the second four crystals. In page 476, right column, lines 10-12, the authors request that such a time / space converter be able to constitute the input stage of a complete optical signal processor in free space, but that such a It does not show what devices can be used in the configuration.

[0010]

SUMMARY OF THE INVENTION Accordingly, a first object of the present invention is an optical device for processing digital optical signals in parallel in free space, comprising: a) at least one n-bit temporal signal; Means for guiding the propagation of digital optical signals comprising a sequence, b) said digital optical signals each comprising at least one
Means convertible into a beam of n signals in guided propagation, comprising two n-bit temporal sequences; c) n digital lights in guided propagation, each comprising at least one n-bit temporal sequence Means for converting said beam of signal into a beam of digital optical signal in free space; and d) converting said at least one n-bit temporal sequence into a spatial image contained in said at least one temporal sequence. Means capable of selecting pre-selected bits in free space in parallel from at least one n-bit temporal sequence of each of said n digital optical signals, e. At least one bit of the spatial image is modifiable in free space in parallel, and at least one bit can be removed by at least one bit. Further comprising: a light means selected in the group consisting of a means capable of inserting a bit and a means capable of modifying the form of at least one bit; and f) means for outputting at least one bit of said spatial image of n bits. An apparatus characterized in that:

In the description and in the claims, the term “propagation in free space” is used to indicate all propagation modes of an optical signal that are not guided by an optical fiber in a device according to the invention.

Typically, at least one of each n bits
Said means for converting said digital optical signal into a beam of n optical signals in guided propagation, comprising: a) converting said digital optical signal in said n digital optical signals in guided propagation, comprising: Means for cloning; b) a first n lines capable of time-aligning the digital optical signal in guided propagation according to a predetermined time interval; and c) the n digital optical signals in guided propagation. Means for controlling and, if necessary, changing the polarization state of

Preferably, the means capable of converting the beam of n digital optical signals in guided wave propagation into a beam of n digital optical signals in free space comprises:
A collimation (c) capable of guiding the n digital optical signals in free space in a predetermined direction and holding these digital optical signals in a predetermined horizontal dimension.
olization means.

[0014] To convert at least one temporal sequence of n bits into a spatial image of n bits containing the same information previously contained in the at least one temporal sequence, typically in parallel. In free space, the n
Means for selecting a preselected bit from the at least one temporal sequence of n bits of each of the plurality of digital optical signals: a) a first optical switching module; b) the first optical switch A second optical switching module arranged in series with respect to the switching module; c) a predetermined inter-relationship with respect to said first optical switching module and each with respect to said second optical switching module. Means for providing first and second pairs of beams of light control pulses having a time interval; d) first and second light control pulses in a collinear form with respect to the direction of propagation of said n digital light signals. A dichroic mirror capable of directing at least one pair of beams; e) light control pulses at a pre-fixed angle of the dichroic mirror; To be incident on the color, and a collimation means for guiding said at least one pair of first and second beams of light control pulses in free space.

Preferably, the first and second optical switching modules respectively change the plane of polarization of the n digital optical signals in free space with the at least one of the first and second pairs of optical control pulses. The first of which can be rotated by a predetermined angle under the action of the two beams
And the second element, the optical switching module also being capable of filtering the n digital optical signal outputs from the first element and the respective second element, respectively, along a predetermined plane of polarization. And first and second polarization analyzers.

The first and second elements are preferably made of first and second indium-doped cadmium tellurium single crystals (CdTe: In).

Typically, the first and second polarization analyzers are oriented substantially perpendicular to each other.

Typically, the output means includes light focusing means capable of guiding the n-bit spatial image in free space in the waveguide propagation means.

Preferably, the output means also includes a second n lines capable of timing the n bits of the spatial image according to a predetermined time interval.

[0020] More preferably, said output means also comprises means capable of converting n bits in said timed guided propagation into a processed digital optical signal comprising at least one temporal sequence of n bits. Including.

[0021] Typically, the means for removing the at least one bit of the n-bit spatial image comprises a third switching module and means for providing at least one light rejection signal.

Preferably, the third switching module is configured to change the polarization plane of at least one of the n digital optical signals output from the first interval timing line and the collimating means into the at least one polarization signal. An element that can be rotated by a predetermined angle under the action of two light removal signals, and said n output from said element.
Also included is a polarization analyzer capable of filtering the digital optical signals along a predetermined plane of polarization.

More preferably, said element is indium-doped cadmium tellurium single crystal (CdTe:
In).

According to a preferred solution, the at least one light rejection signal is collinear with and overlaps one of the n digital light signal outputs from the first interval timing line. .

In a preferred design, while the signal and control beams are applied at right angles to a plane 1100 of the crystal, an electric field is applied to this plane 1100 at right angles.

Preferably, said means for removing said at least one bit of said spatial image of n bits is transparent to a wavelength of said n digital optical signals downstream of said third switching module. And means for reflecting the wavelength of the at least one light removal signal.

[0027] Typically, the means capable of inserting at least one bit into the n-bit spatial image comprises means for supplying at least one optical insertion signal to the first and second optical switching modules. Including.

Preferably, the at least one optical insertion signal has the same wavelength and power as the optical signal constituting the n-bit spatial image.

Still further, the means for supplying the at least one optical add signal includes: {means that are transparent to half the power of the n digital optical signals and the at least one optical add signal; Means capable of reflecting the other half of the power.

A typical example of the transparent means is 5
Includes 0/50 light beam splitter.

Preferably, the 50/50 optical beam splitter is substantially 45 times in the direction of the n digital optical signals and the at least one optical add signal.
Angled by degrees, the direction of the digital optical signal is substantially perpendicular to the direction of the at least one optical add signal.

More preferably, said means for providing at least one optical add signal comprises:
Means for collimating said at least one optical insertion signal in free space so as to be incident on a / 50 light beam splitter and overlap one of said n digital optical signals. .

Typically, said means for providing said at least one optical add signal controls a polarization state of said signal,
Further, a means for changing the polarization state as necessary is also included.

Preferably, the means for modifying the form of the at least one bit of the spatial image of n bits comprises the first of the at least one pair of light control pulses of the first and second beams of light control pulses. And means capable of varying said time interval between the second beams.

According to one embodiment, the second n lines have at least a different amount of time with respect to the other bits of the spatial image of n bits than the bits at the output from the input means. At least one bit of the n-bit spatial image is timed by the time one bit is delayed at the output.

According to a variant, said optical means capable of modifying at least one bit of said n-bit spatial image in free space in parallel performs an algebraic operation on said n-bit spatial image. Means that can be used.

According to another variant, said optical means capable of modifying at least one bit of said n-bit spatial image in free space in parallel is symmetric with respect to said n-bit spatial image. Also includes means capable of performing operations.

Preferably, said means capable of performing said algebraic operation comprises: said n of said spatial image output from said first and second optical switching modules.
It includes at least one element capable of rotating the plane of polarization of the bit by a predetermined angle under the action of the light beam enabling the algebraic operation.

[0039] More preferably, said means capable of performing said algebraic operation also comprises at least one means transparent to said n-bit first predetermined plane of polarization of said spatial image. , Said transparent means also comprising a second plane substantially perpendicular to said first plane.
Can be deflected.

[0040] Still more preferably, said means capable of performing said algebraic operation also includes at least one mirror capable of reflecting said n bits of said spatial image.

Typically, said means capable of performing said symmetric operation comprises said n of said spatial image output from said first and second optical switching modules.
It comprises at least one element capable of rotating the plane of polarization of the bit by a predetermined angle under the action of the light beam enabling said symmetric operation.

Further, said means capable of performing said symmetric operation comprises at least one means transparent to said first predetermined polarization plane of said n bits of said spatial image. And said transparent means is also capable of deflecting a second plane of polarization substantially perpendicular to said first plane.

Further, said means capable of performing said symmetric operation also include means capable of reflecting said n bits of said spatial image.

Preferably, said means capable of performing said symmetric operation also include means capable of changing said n-bit polarization state of said spatial image.

A method for processing digital optical signals in parallel in free space constitutes a second object of the invention, comprising: a) sending a digital optical signal comprising at least one temporal sequence of n bits; B) converting the digital optical signal, each including at least one temporal sequence of n bits, into a beam of n digital optical signals in guided propagation; c) transforming the at least one temporal sequence of n bits. Converting said beams of n digital optical signals in guided propagation into beams of n digital optical signals in free space, respectively, including: d) said at least one temporal sequence of n bits in said at least one temporal sequence. The n digital images to be converted into the n-bit spatial image containing the same information as previously contained in one temporal sequence. Selecting a preselected bit in parallel and in free space from said at least one temporal sequence of n bits of each of said optical signals, at least one of said n bits of said spatial image.
Modifying in free space in parallel with the bits.

A third object of the present invention comprises an apparatus for modifying the duration of at least one bit of an n-bit temporal sequence which is converted into a corresponding n-bit spatial image, comprising: The n bits at the end
N where the bits are later derived in the form of an n-bit temporal sequence
光 n waveguides are separated from at least one of the other bits of the temporal sequence by a different time interval than that separated by the initial temporal sequence. And at least a portion of the optical waveguide having a length selected such that one bit passed at the input to the optical waveguide of the signal is separated from at least one of the other bits of the temporal sequence. .

A special feature of the optical device according to the invention consists in enabling the processing of digital optical signals and the holding of said signals in optical form under the control of optical control signals.

As mentioned above, this overcomes the band limiting of conventional electronic devices and the slow response times of electronically controlled optical devices (eg, liquid crystals and thermal light modulators). Make it possible.

A further advantage of the device according to the invention is that it allows the processing of signals in free space, thereby benefiting from the "space" resources provided by the optics, whereby conventional electronic processors and optical fibers It consists of enabling higher speed acquisitions as compared to the typical series processing in the system and also in the waveguide.

Further, the optical device according to the present invention has a wavelength, for example, about 1 which is typical of an optical fiber type transmission system.
Allows processing of signals with wavelengths of 300 nm and 1550 nm.

The features and advantages of the present invention will now be described with reference to the embodiments shown, by way of non-limiting example, in the accompanying drawings.

[0052]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiment of FIG. 1 shows an optical arrangement for the parallel processing in free space of 4 bits of a digital optical signal 6 comprising at least one temporal sequence 7a of 4 bits. .

The input means for generating the digital optical signal 6 comprises a DFB which emits at about 1550 nm and is modulated by the word generator 600 at a frequency of about 140 Mbit / s.
Includes laser 60 with (pigtailed) semiconductor.

The power of the digital optical signal 6 output from the laser 60 is about 1 mW. An optical amplifier (not shown), for example a fiber with erbium-doped and variable gain, applies approximately 15 mW of power to the input means 60 and 6 to compensate for losses from subsequent stages.
It is possible to have in the output from 00.

As described above, the optical fiber 1 × 4 coupler 16
Are four identical copies 1 of a 4-bit temporal sequence 7a,
The amplified digital optical signal 6 is cloned to obtain 2, 3, and 4.

The four lines (line portions) have different lengths of optical fibers 110, 120, 130,.
140, the four digital optical signals 1,
2, 3, and 4 are about 149 Mbits / sec, four times the bit time of about 7.12 ns. Since the speed of light in the glass is about 2 × 10 ⁸ m / sec, the path needs to be increased by 1.428 m to work with a 7.12 ns delay. The line portion 110 of the optical fiber from which the first bit is taken out is lengthened by 4.284 m, the portion 120 corresponding to the second bit is lengthened by 2.856 m, and the portion 130 corresponding to the third bit is 1.428 m. But the line portion 140 of the optical fiber associated with the fourth bit is not lengthened. The optical fiber portions 110, 1
20, 130, 140 are wound on a reel having a diameter large enough to avoid loss due to excessive curvature.

First, the digital optical signal 1 is converted to the bit time 3
Thus, the second digital optical signal 2 is delayed by a time corresponding to twice the bit time, and the third digital optical signal 3 is delayed by a time corresponding to one time the bit time. However, since the fourth digital optical signal 4 is not delayed, the output from the four fiber optic line sections 110, 120, 130, 140 is output from the four fiber optic line sections 110, 120, 130, 140.
, The first, second, third and fourth bits of the temporal sequence 7a are simultaneously found in a transformed state (FIG. 7).

FIG. 7 shows a 4-bit temporal sequence (four).
(bit temporal series) 7a to 7a
4-bit spatial image (four bit) that selects the same information as
2 shows the conversion to spatial figure 7b.

This procedure requires the following:ク ロ ー ン cloning in four identical temporal sequences, shown together in temporal sequence 7a 7b, 遅 延 delay lines 110, 120, 130, in temporal sequence 7b
140 to generate a temporal / spatial image 7c by delaying each other by a multiple of the bit time, {appropriate switching modules 2000, 4000
To properly select the image 7d from the temporal / spatial image 7c.

As shown in FIG.
1, 102, 103, and 104 control the polarization state of the four optical signals 1, 2, 3, and 4 output from the four optical fiber line sections 110, 120, 130, and 140, if necessary. To change.

In a preferred embodiment, said means 101, 102, 103, 104 for controlling the polarization state of said four signals 1, 2, 3, 4 and changing them if necessary.
Consists of four polarization controllers, which further comprise, for example, four pairs of fiber optic polarization rotators (rot
ator). Desirably, each pair of polarization rotators comprises, for example, two disks made of a suitable diameter metal and / or plastic on which the fiber optic coil is wound. The windings produce birefringence in the orthogonal plane of the optical fiber in the direction of propagation of the signals 1,2,3,4. By appropriately selecting the diameter size of the coil, it is possible to generate a λ / 4 surface with one turn of the optical fiber wire and a λ / 2 surface with two turns. If an arbitrary polarization state can be obtained by rotating the λ / 2 plane and the λ / 4 plane using the means 101, 102, 103, and 104, the polarization of each of the four signals 1, 2, 3, and 4 is obtained. It is possible to adjust the state with high accuracy.

The means 101, which can control the polarization state of the signals 1, 2, 3, 4 and change it at any time,
The collimating means 5 disposed downstream of 102, 103, and 104 comprises:
Serves as a boundary between the first switching module 2000 and the portion in free space (about 20 cm) where the second switching module 4000 is located.

The means 5 can convert the four digital optical signals 1, 2, 3, and 4 during guided wave propagation into four digital optical signals 111, 112, 113, and 114 in free space. Furthermore, said means 5 comprises said digital optical signal 111, for all parts in free space.
112, 113, 114 can be collimated,
These signals can be kept in parallel and within the lateral dimensions of the first optical switching module 2000 and the second optical switching module 4000.

As shown in FIG. 2, the means 1 can control the polarization state and change it if necessary.
The four optical fibers 11, 12, 13, 14 at the output from 01, 102, 103, 104 are arranged in a linear shape with substantially minimum dimensions. Such a linear shape corresponds to the four optical fibers 11, 12, 13, and 14.
From plastic clad
dding) and thereby the clad stripped optical fibers can be obtained by gluing them close together on a glass mount.

Since the outer diameter of the 1550 nm cladding of a single mode optical fiber is about 125 μm, the overall dimensions of the array of optical fibers 1000 thus formed is:
It is about 500 μm. Thus, the spacing between the outermost signals 1 and 4 at the output from the set 1000 is
It is about 375 μm.

For example, a grin type lens 1001 having a pitch corresponding to 0.25 is used to generate four digital optical signals 11 output from the array 1000.
1, 112, 113 and 114 are collimated. The function of the grin lens 1001 is based on a radial change in the refractive index rather than on the lateral curvature as in conventional lenses. The green lens 1001 is:
The optical fibers 11, 12, 1 of the array 1000
3 and 14, so that the signals 111, 112, 113, 114 output from the array 1000 before the signals 111, 112, 113, 114 are excessively divergent.
It is more desirable than a conventional lens because it allows all of 112, 113, 114 to be collected.

In the embodiment shown in FIG. 2, a convex lens 1010 having a focal point of about 80 nm is arranged at a distance of about 8 cm from the green lens 1001, and the four lenses output from the green lens 1001. Signal 1
The divergence of 11, 112, 113 and 114 is corrected. The four signals 1 input to the green lens 1001
11, 112, 113, 114 are, in fact, displaced with respect to the axis of the Glin lens 1001, so that when output from this lens, they produce optimal collimation, but considerable divergence.

According to the modified example, the collimating means 5 described above can be used as described below with reference to FIG.
One digital light signal 1, 2, 3, 4 can be generated using a set of microlenses, one for each.

At the output from the collimating means 5, the four signals 111, 112, 113, 114 are substantially well collimated in parallel over the entire part of the free space. In particular, the two outermost signals of signals 111 and 114 are separated by about 3.8 mm.

As shown in FIG. 3, the first optical switching module 2000 includes a first indium.
Cadmium telluride single crystal (CdTe: I
n) 200 and the first polarization analyzer 20.

The first member having a size of about 5 × 5 × 15 mm
Of the signal 111, 112, 113,
Electrodes for applying a voltage corresponding to the input / output surface 114 are disposed on a plexiglass mount provided with an opening provided therein.

In this embodiment, the signal propagates at right angles to the applied electric field.

The first polarization analyzer 20 is preferably composed of a polarization division cube.

The first optical switching module 2
000, the optical signals 111, 112, 11
The state of polarization shown in FIG. 3 at 3, 114 is adjusted by the means 101, 102, 103, 104, as described above, which can control the state of polarization and change it if necessary. . This adjustment is based on the optical signals 111, 1
It is done so that 12, 113, 114 are polarized in a linear form at 45 ° with respect to the birefringence axis occurring in the first single crystal 200. The birefringence is caused by the electro-optic effect such that the plane of polarization 1 of the signals 111, 112, 113, 114 at an angle of 90 ° is obtained such that a plane of polarization perpendicular to the plane of incidence 10 is obtained as indicated by arrow 100.
It is induced by applying a voltage to the first single crystal 200 capable of rotating 0.

In FIG. 3a, the first polarization analyzer 20 is oriented to shield the signals 111, 112, 113, 114 output from the first single crystal 200. Under such a condition (off condition), the first optical switching module 2000 is closed and does not allow transmission of the signals 111, 112, 113, 114.

The first light control beam 320 of 1064 nm (CdTe: In is a wavelength at which In shows a photoconductive peak value) is used for the first light control beam 320.
When the single crystal 200 is irradiated, the reverse electric field generated by the carrier wave generated by the light inhibits the electro-optic effect.
As a result, in the first single crystal 200, the polarization plane 10 of the signals 111, 112, 113, 114 is not further rotated, and the polarization analyzer 20 passes the signals as shown in FIG. 3b. (ON condition).

The first single crystal 200 is characterized by the following two response times. The time t associated with the generation of the carrier light and the generation of the reverse electric field.
_on , _{on the} other hand, the time t _{of f} for the process of charge regeneration and recovery of the initial conditions.

Experiments have shown that a sufficiently high power density (pow
er density) (when having about 10 ⁵ W / cm ^2), the time t _on is very fast (typically, a few ns), tendency that exactly matches the rise time of the first optical control pulse 320 It was shown that there is. On the other hand, time t
_off is significantly slower (typically a few microseconds) and is closely related to the spatial distribution of the first light control pulse 320. As a result, a device having a response speed in the order of nanoseconds cannot be generated only by the first single crystal 200.

The important features of the first single crystal 200 are as follows.
The fact is that for wavelengths above about 1250 nm, it is substantially transparent (having an absorption coefficient substantially lower than 0.2 cm ^-1 ). Therefore, the optical device according to the present invention can be used in an optical communication system in the second and third windows.

The description and comments made with respect to the first optical switching module 2000 are described in the second optical switching module 2000.
The present invention is also applicable to the second optical switching module 4000 including the single crystal 400 and the second polarization analyzer 40.

As shown in FIG. 4, the first switching module 2000 and the second switching module 4000 are configured in series, and each of the polarization analyzers 20 and 40 is crossed, and these analyzers are mutually connected. First light control pulse 3 delayed by a predetermined time
20 and the second light control pulse 340.

First, when the planes of polarization of the signals 111, 112, 113, and 114 input to the first single crystal 200 are rotated by the electro-optic effect and output from the single crystal, the signals 111 and 112 are output. , 113, 114 are shielded by the first polarization analyzer 20 (the first module is in the off condition). When the first light control pulse 320 arrives, the electro-optic effect of the first single crystal 200 is blocked (the first module is in the ON condition). Therefore, the signals 111, 112, 113, 11
4 passes through the first polarization analyzer 20 and enters the second single crystal 400, where the plane of polarization undergoes a 90 ° rotation due to the electro-optic effect. Since the second polarization analyzer 40 is oriented at right angles to the first polarization analyzer 20 of the first optical switching module 2000, the second optical switching module 40
00 is off when the signals 111, 112, 113, 1
14 are transmitted through a response time corresponding to t _{on and} are emitted from the modules 2000 and 4000. The optical switching module remains in such a condition, that is, opens for the entire deenergization time t _off of the first single crystal 200.

[0083] To obtain a full open passage time of said at small temporal sequence than t _off the first and second modules 2000 and 4000, a small predetermined time after interval t _w than t _off, suitable waveguide means 30 The second control pulse 310 is sent to the second single crystal 400. The second optical switching module 4000 is then energized (the second module is in an on condition) and the signal 11
1, 112, 113, 114 do not cause any further rotation of the plane of polarization and are therefore blocked by the second polarization analyzer 40 with a response time t _off .

The first optical switching module 2000 and the second optical switching module 40 in series
00 fully open passage time can be adjusted by selecting a delay t _w between the first optical control pulse 320 second optical control pulse 310. This delay t _w typically should not be greater than the quenching time t _off of the single crystals 200 and 400. Further, this delay must not be less than t _on to allow the first single crystal 200 to respond to the first light control pulse 320.

In FIGS. 3 and 4, the single crystals 200 and 4 by the light control pulses 320 and 310 are shown.
Irradiation of the signals 111, 112, 113, 114
FIG. 5 shows a case where the first light control pulse 320 and the second light control pulse 310 intersect with each other.
Indicate that the signals 111, 112, 113, and 114 arrive at the single crystals 200 and 400 in a collinear manner.

As shown in FIG. 5, the dichroic
A mirror 50 disposed between the first module 2000 and the second module 4000, the mirror being transparent to the wavelengths of the signals 111, 112, 113, 114; Beam 320
And the wavelength of the second light control beam 310 is reflected. Typically, the wavelength of the signals 111, 112, 113, 114 is about 1550 nm and the wavelength of the first and second light control beams is about 1064 nm.

The digital optical signals 111, 112, 1
In the case where the wavelengths of the first and second light control pulses 320 and 310 are substantially the same as those of the first light control pulse 320 and the second light control pulse 310 (not shown), the dichroic mirror 5
0, for example, the digital optical signals 111, 112, 1
13, 114 and a beam splitter capable of transmitting substantially half of the power of the first light control beam 320 and the second light control beam 310 and reflecting the other approximately half thereof. Can be replaced.

The dichroic mirror 50 controls the optical signals 111, 112, 113, 114 and the first
The light control beam 320 and the second light control beam 310 are substantially inclined at an angle of 45 ° with respect to the propagation direction (FIG. 5). The first light control beam 320 from a direction substantially perpendicular to the direction of the signals 111, 112, 113, 114 is reflected by the dichroic mirror 50 after the signals 111, 112, 113, 114 Is incident on the first single crystal 200 in a direction that is collinear but opposite to the direction (irradiation propagating in the opposite direction).

Furthermore, the second light control beam 310, also from a direction substantially perpendicular to the directions of the signals 1, 2, 3, 4, is reflected by the dichroic mirror 50 after the signal 111, 112, 113, 11
The second single crystal 400 is incident on the second single crystal 400 in the same direction as that of the second single crystal 4 (the same propagation irradiation).

Both illumination modes, propagation in the opposite direction and propagation in the same direction, are equally effective for switching purposes.

As shown in FIG. 6, the first and second optical pulse control beams 320 and 310 having a wavelength of about 1064 nm are preferably generated by a Nd: YAG Q-switched laser 300. . The FWHM period of the pulse is about 5 ns. The light control beam 3000 output from the laser is split into two equal parts by a beam splitter 33 and a first multimode optical power fiber having a core diameter of about 600 μm.
fiber 32) and a second multimode power optical fiber 31. The lengths of the first and second optical fibers 32 and 31 are such that the first and second light pulses 320 and 310 are applied to the first single crystal 200 and the second single crystal 400 at different time intervals. They are different from each other so as to be incident. The delay t between the first and second light control pulses 320 and 310
_w determines the total open time of the first and second series of optical switching modules 2000 and 4000, as described above.

In this case, the full open time is equal to the bit time, but the interval between two adjacent parts is equal to the duration of the series of bits being transformed, which in the case shown in FIG. Is four times the bit time.

Two plano-convex lenses 1 having a focal point of 30 mm
The first and second optical control elements 5 and 25 output from the first and second optical fibers 32 and 31 so that the diameter of the beam incident on the single crystals 200 and 400 is about 7 mm. The beams 320 and 310 are collimated. Thus, the first and second light control beams 320 and 310 completely illuminate the input surfaces of the single crystals 200 and 400, which are approximately 5 × 5 mm. Further, the plano-convex lenses 15 and 25 are provided with the first
And the second light control beams 320 and 310 are approximately 45
The light control beams are directed in free space so as to be incident on the dichroic mirror 50 at an angle of °. .

In the illustrated embodiment, the single crystal 2
The energy of the first and second light control pulses 320 and 310 incident on 00 and 400 is about 1 mJ. At this level of energy, the times t _on of the single crystals 200 and 400 are equal to the rise times of the first and second control pulses (about 3 ns) (about 10 minutes of the maximum intensity value).
% Corresponding to the time required for the pulse to increase from about 90% to about 90%).

In the case of CdTe: In single crystal, the first
The first and second light control pulses 320 and 310 have an energy of 3 to switch the second and second switching modules 2000 and 4000 in series.
It has been observed in experiments that it should be greater than or equal to 50 μJ.

First and second optical switching modules 2000 and 400 forming said spatial image 7d
The four bits output from 0 are ready to produce subsequent processing operations in parallel in free space.

[0097] The subsequent processing operation includes means 7000, 71, for removing one bit of the 4-bit spatial image 7d.
72, 73, 74 and means 81, 82, 83, 84, 80, 8 for inserting one bit into the spatial image 7d.

In particular, FIG. 1 shows an alternative where the third bit is removed and the second bit is inserted.

The means for removing the third bit of the spatial image 7d comprises the downstream side of the collimating means 5 and the first and second optical switching modules 2
A third optical switching module 7000 located upstream of 000 and 4000, and means (not shown) for providing a third signal 73 of the four optical rejection signals 71, 72, 73, 74. .

The first optical switching module 2
000 is described in a third indium-doped cadmium tellurium single crystal (CdT
e: In) 700 and the third optical switching module 7000 including the third polarization analyzer 70.

In the embodiment as shown in FIG. 1, the third polarization analyzer 70 outputs the third cancellation signal 7.
The optical signals 111, 112, 113, 114 output from the third single crystal 700 pass when 1, 72, 73, 74 are not present (the third module is in the off condition); and Light removal signals 71, 72, 7
3, 74 are oriented to allow the light signal to be interrupted when illuminating the third single crystal 700 (the third module is in an on condition).

The third digital optical signal 113 for the third bit to be removed is thus shielded,
The third digital optical signal 113 illuminates an area of the third single crystal 700 that is propagated by the third optical removal signal 73.

The CdTe: In single crystal is irradiated, and the power density of the removal signals 71, 72, 73, 74 is about 0.5 m.
If it is smaller than W / mm ² , the removal signals 71, 7
When 2, 73, 74 are placed more than about 0.5 mm from the third digital optical signal 113, the spatial image 7
d removal of the third bit corresponds to other digital optical signals 111, 112,.
It was found that it did not hinder the propagation of 114.

The dimensions of the third single crystal 700, ie, 5
× 5 × 15 mm is a dimension such that the optical signals 111, 112, 113, 114 can be completely included at a distance of at least 0.5 mm from each other.

The third light removal signal 73 is approximately 1064
A laser (not shown) having a wavelength of nm and made from neodymium-doped fiber is pumped by an approximately 810 nm laser diode that emits a continuous signal.

In a preferred embodiment, four on / off switches (not shown) are used to control the spatial image 7d.
The four light removal signals 71, 72, 73, and 74 are selected according to the bits removed in. The on / off switch is controlled electrically, for example by using a common integrated electro-optic modulator, or optically, for example by using an optical switching module similar to that described above. Can be.

The signals 111, 112, 113 and 114 relating to the four bits of the spatial image 7d are about 1550n.
In order to combine the first signal of m with the second signal of about 1064 nm, it is fiber coupled by means of four 2 × 2 fusing couplers before said collimating means 5 described above.

The signals 71, 72, 73, and 74 are output from the same fibers 11, 12, 13, and 14 as the optical signals 111, 112, 113, and 114, respectively, and undergo the same collimation process. The digital optical signals 111, 112, 113, 114
Is perfectly aligned with and overlaps.

The elimination signals 71, 72, 73, 74 and the digital optical signals 111, 112, 113, 11
In the embodiment shown in FIG. 1 in which the third optical switching module 7000 is coupled in a guided wave propagation before the collimating means 5, the third optical switching module 7000 is located downstream of the collimating means 5 as previously described. And upstream of the first and second switching modules 2000 and 4000.

In another embodiment in which the coupling between the cancellation signals 71, 72, 73, 74 and the digital optical signals 111, 112, 113, 114 is performed in a different way, for example in a free space, 3 switching module 7000 may also be located downstream of the first optical switching module 2000 and the second switching module 4000, with the removal at any given sub-point in free space. Signal 71,
72, 73, 74 can be inserted. These two solutions are completely equivalent.

An interference filter (not shown) is arranged downstream of the third module 700 and upstream of the first module 2000, and the interference filter (not shown)
11, 112, 113, 114, which are transparent to the wavelength of about 1550 nm,
The wavelengths of about 1064 nm of 72, 73 and 74 are reflected.
The interference filter is thus capable of providing the rejection signal 7 for the third optical switching module 7000.
1, 72, 73, 74 and the first counter-propagating first light control beam 320 for the first light switching module 2000 are prevented from reaching modules not associated therewith.

Using the optical device shown in FIG. 1, an experimental operation for removing the second bit of the temporal sequence “1111” of the bit of about 140 Mbit / sec input to the device in the RZ format is performed. Was done. In FIG. 11, a temporal sequence “1111” (FIG.
a) and a modified temporal sequence "1011" (FIG. 11b) output from a device obtained with an oscilloscope having a suitable photodetector and a passband of about 1 GHz.

The means for inserting the second bit into the spatial image 7d comprises four insertion optical signals 81, 82, 83, 8
4, a device (not shown) for supplying a second signal 82, means 80 for collimating the inserted signals 81, 82, 83, 84, and a beam splitter 8.

Four optical insertion signals 81, 82, 83, 84
Said means for providing a second signal 82 of about 1550n
A laser diode DFB (not shown) that provides a continuous signal with a wavelength of m and a fiber output power of about 1 mW
It is desirable to include

For example, the insertion signals 81, 82, 83,
The collimation means 80 of 84 collimates the signals 81, 82, 83, 84 in free space and converts these signals at an angle of about 45 ° to the beam splitter 8.
And then the digital optical signals 111 and 11
2, 113, 114, in other words, the digital optical signals 111,
A Glin lens that guides these signals to overlap one of 112, 113, 114 is included.

The beam splitter 8 transmits substantially half of the power of the digital optical signals 111, 112, 113, 114 and the insertion signals 81, 82, 83, 84, and transmits the other approximately signals. Half can be reflected.

The third optical switching module 7
000 and the beam splitter 8 arranged on the upstream side of the first optical switching module 2000, the digital optical signals 111, 112, 11
3, 114 and the insertion signals 81, 82, 83, 8
4, and the direction of the digital optical signals 111, 112, 113, 114 is substantially perpendicular to the direction of the insertion signals 81, 82, 83, 84. .

For example, as described above, a means (not shown) such as a pair of polarization rotators disposed upstream of the collimating means 5 is operated by the applied voltage to generate the first and second signals. 2 switching modules 2000
And control the polarization state of the second insertion signal 82 to be polarized at 45 ° in a linear fashion with respect to the birefringence axis induced at 4000 and change it if necessary.

In the embodiment according to FIG. 1, the first and second optical switching modules 2000 and 4
000 sequentially selects predetermined bits from each of said digital optical signals 111, 112, 113, 114 in parallel free space, and consequently said switching module converts said 4 bit temporal sequence 7a to At the moment of conversion to the spatial image 7d, an asynchronous insertion of the second bit into the spatial image 7d occurs. As a result, the synchronization of the insertion is synchronized with the first and second switching modules 2 in series with respect to the four digital optical signals 111, 112, 113, 114.
Guaranteed by synchronization of 000 and 4000.

According to another embodiment, the insertion of the second bit is such that the digital optical signals 111, 112, 113, 11 constituting the spatial image 7d of four bits.
4 can be implemented by inserting the bits into the correct spatial location synchronously with all four. However, in comparison with the latter embodiment, the embodiment shown in FIG. 1 has the digital optical signals 111, 112, 113, 1
There is no need for timing between 14 and the inserted bits. Furthermore, for the insertion of the bits, it is possible to use the same first and second switching modules 2000 and 4000 in series which convert the temporal sequence of the four bits into the spatial image 7d of four bits. Therefore, the embodiment shown in FIG. 1 is much simpler to manufacture.

The duration of the second insertion bit is equal to the total open time of the first and second switching modules 2000 and 4000. In order to prevent the spatial overlap of the 4 bits in the subsequent conversion of the spatial image 7d into a 4 bit temporal sequence 7e of the processed digital optical signal 900 output from the device,
Preferably, the duration is equal to or shorter than the bit time.

The inserting means for the second bit is also capable of shielding or transmitting the inserted signals 81, 82, 83 and 84 according to the bit inserted in the spatial image 7d. It is desirable to include a system of two on / off switches (not shown). The on / off switch may be controlled electrically, for example by using a common integrated electro-optic modulator, or optically using an optical switching device similar to that shown above. Can be.

The optical device shown in FIG. 1 performs an experimental operation on the RZ format of the third bit in the time sequence “1101” of the bit input to the device and the asynchronous insertion at approximately 140 Mbit / sec. Was done.
In FIG. 12, the temporal sequence "1101" (FIG. 12a) input to the device and the modified temporal sequence "output from the device" obtained by an oscilloscope having a suitable photodetector and a passband of about 1 GHz. 1111 "
The record of (FIG. 12b) is reported.

In this case, it has been found that the third insertion bit is lower and wider than the other bits. The relatively narrow amplitude is such that the insertion of the third bit has a lower power (about 1 mW) than the power of the digital optical signal output from the optical amplifier after the beam splitter 8 and the third bit after the beam splitter 8 About 1.5 mW each due to poor matching of the third optical insertion signal to the spatial position
Due to the fact that it was performed by a continuous laser signal with a power of On the other hand, the greater width of the third insertion bit compared to the other bits has a rise time of about 3 ns, which is the total open time of the first and second optical switching modules 2000 and 4000, and Due to the fact that the light control beams 320 and 310 were larger than the physical duration of the bits in RZ format at about 140 Mbit / s.

Nevertheless, these deficiencies are clearly due to the use of a continuous 1.5 mW laser signal that correctly aligns the optical insertion signal with respect to the spatial position with respect to the third bit, and that the first And the total open circuit time of the second optical switching modules 2000 and 4000 can be corrected by using a control beam having a rise time equal to the physical duration of the bit.

The embodiment shown in FIG. 1 may also include means for changing the form of the four bits of the spatial image 7d.

The means converts the “non-return-to-zero (NRZ)” coded bits of the spatial image 7d into “return-to-zero (RZ)” coded bits.

According to a preferred embodiment, said means comprises said digital optical signals 111, 11 corresponding to one bit.
The ratio (duty cycle) between the physical duration of 2, 113, 114 and the bit time is halved. Thus, in the NRZ format, since the ratio is about 1, the means make it possible to obtain a ratio of about 0.5.

The halving is accomplished by adjusting the total open time of the first and second optical switching modules 2000 and 4000 in series to remain open for a time equal to about half the bit time. Will be

By adjusting the total open time in this way, the first and second optical switching modules 2000 and 4000 allow the conversion of the 4-bit temporal sequence 7a into the spatial image 7d. And modifying the duty cycle of the bits of the spatial image 7d.

The determination of the total open time must be done very carefully, as this determination determines the form that the selected bit will take. Thus, as mentioned above, the first and second light in series are the same as the rise times of the first and second light control beams 320 and 310 (about 3 ns in the illustrated embodiment). Switching
It is necessary to consider the total response time during opening and closing of modules 2000 and 4000, ie, t _on .

Thus, the first and second optical switching modules 2000 and 4000 of the embodiment shown in FIG. 1 cannot remain open for a total time of less than about 6 ns.

Therefore, the conversion is performed, for example, on the temporal sequence 7
a, can be implemented at a bit rate of 70 Mbit / s, and this bit rate can therefore be reduced by the first and second optical switching modules 2000 in series.
And 4000 requires a total open circuit time of about 7.14 ns.

The total open circuit time is determined by the first and second optical switching modules 2000 and 4 in series.
000 can be adjusted by changing the length of the first and second optical fibers 32 and 31 to take into account the total response time t _on during opening and closing of the 000.

For example, in the case of the bit rate of 70 Mbit / s described above, about 7.14 of the first and second optical switching modules 2000 and 4000 are used.
ns, to obtain a total open time of ns.
Of the first and second optical switching modules 20 with a delay of about 4 ns.
The lengths of the first and second optical fibers 32 and 31 are selected to be incident on 00 and 4000.
This delay is about 80 for the first optical fiber 32.
It is obtained by lengthening the second optical fiber 31 by cm.

In such a case, the duty ratio of about 0.5
The operation of transforming the temporal sequence of four bits "1111" input to the device at about 70 Mbit / s and coded NRZ to four corresponding RZ coded bits with cycles was performed in the experiment. Was done. In FIG. 13, the NRZ-coded input temporal sequence “111”
For "1" (FIG. 13a) and the corresponding temporal sequence output from the device (FIG. 13b), recordings obtained with a suitable photodetector and oscilloscope with a passband of about 1 GHz are reported.

[0137] The device shown in FIG.
Using the same optical switching modules 2000 and 4000 for both the conversion of the temporal sequence 7a of bits into the second bit and the insertion of the second bits and the modification of the form of the bits of the spatial image 7d Enable. Thus, this allows the creation of a device with a very simple and compact architecture that benefits from the full power of parallel optical structures in free space.

As shown in FIG. 1, the output means converts the 4-bit spatial image 7d to be processed, if necessary, into a temporal sequence 7e of a processed digital optical output signal 900.

The second output means is connected to the line 910,
Four optical fiber lines (portions) 910, 920, 9 for transmitting the bits output from 920, 930, 940 to the processed digital optical output signal 900.
The optical means 9 focuses the four bits in free space at 30, 940 and combiner 90.

As shown in FIG. 2, it is desirable that the light means 9 for focusing the four bits of the spatial image has a symmetrical structure with respect to the collimation means 5. As described above, the light means 9 is provided with the first lens 901.
The 4th output from the first and second optical switching modules 2000 and 4000 at the input plane of the green lens 9001 located at the 0 focal plane.
It includes said first lens 9010 having a focal point of about 80 mm for focusing said digital optical signals 111, 112, 113, 114 in free space corresponding to bits.

The digital optical signals 111, 112, 113, 114 coming out of the green lens 9001
Has a high degree of convergence, so that the four optical fiber lines 910, 920, 9 arranged in a linear shape similar to that described above for the collimating means 5
The waveguides 30 and 940 facilitate the guided wave propagation.

Such a linear shape can be easily reproduced with very high accuracy. The fiber array 1
The precision with which 000 and 9000 must be formed is
It depends on the core diameter of the single mode fiber, which is about 9 μm at about 1500 nm. Therefore, the output array 900
0 of one of the optical fiber lines 910, 920, 930, 940 corresponds to the fiber 1
If it is offset by more than the dimension with respect to 1, 12, 13 or 14, the bits propagated in the fiber will be incorrectly combined, so that information about one of these bits may be lost.

The accuracy of the linear shape as shown in FIG. 2 is solely due to the maximum diameter of the cladding of a 1550 nm single mode fiber, which is about 125 μm with a tolerance of less than about 1 μm. This ensures optimal coupling of the second digital optical signal 111, 112, 113, 114 in the fiber.

According to the modified example, the above-mentioned 4 input to the device is performed.
Optical fibers 11, 12, 13, 14 and optical fiber lines 910, 920, 930, 940 output from the device.
Means that in the case of eight digital optical signals, they can be arranged in a two-dimensional shape similar to that shown in FIG.

The four optical fiber lines 9 of different lengths
10, 920, 930, 940 delay the second four bits of the second spatial image 7d from each other by an amount several times the bit time which is about 7.12 ns at about 140 Mbit / s. Let it. That is, the optical fiber line 91
The length of 0, 920, 930, 940 is about 7.12 ns
Approximately 1.428m, which is the length needed to handle the delay of
Differ from each other by several times the amount of

If it is necessary to process the temporal sequence 7a input to the device according to the present invention, to construct the 4-bit output temporal sequence,
The bits are delayed back with respect to the input bits. For example,
The first bit that is delayed at the input by three times the bit time is not delayed at the output, but the fourth bit that is not delayed at the input is delayed at the output by three times the bit time.

As a result, the fiber portion 910 from which the first bit is extracted is not extended, and the fiber portion 920 corresponding to the second bit is extended by 1.428 m, and the third
The fiber portion 930 corresponding to the bits of 2.856 m
And the part corresponding to the fourth bit is 4.28
It is extended by 4m.

The optical fiber lines 910, 920, 93
0,940 is also wound onto a reel having a diameter large enough to avoid causing losses due to too large a curvature.

The 4 × 1 coupler 90 is connected to a single optical fiber 990, possibly to the input temporal sequence 7a.
Convey the four bits emerging from the fiber optic lines 910, 920, 930, 940 to obtain the digital optical output signal 900 including the temporal sequence 7e of bits processed with respect to.

On the upstream side of the green lens 9001, the digital optical signal 1 corresponding to the 4 bits
A different filter (not shown) is disposed that is transparent to the wavelength of about 1550 nm of 11, 112, 113, 114 and reflects the wavelength of about 1064 nm of the second co-propagating light control beam 310. It is desirable. In this way, the filter is configured to
Optical control beam 310 is coupled in the fiber to prevent overlapping with the four bits of the spatial image.

According to another embodiment, the fiber optic lines 910, 920, 930, 940 are used to change the duration of the four bits of the spatial image 7d, and hence the bit rate, to change the bit rate. Digital optical signal 1
11, 112, 113, 114 can be delayed from each other by an amount several times longer or shorter than the bit time.

Further, the optical fiber lines 910, 92
The dimensions of 0, 930, 940 can be adjusted according to the required new bit time.

For example, to increase from a bit time of about 7.14 ns to a time of about 9.64 ns, a dimension of about 1
A multiple of 50 cm of fiber optic pieces suitable for operation at 40 Mbit / s are provided on the fiber optic lines 910, 920,
930 and 940. Thus, the line 940 corresponding to the fourth bit of the temporal sequence 7e to be reconstructed
Is extended by about 150 cm (50 cm × 3), and thus is increased from about 4.284 m to about 5.748 m, and the line corresponding to the third bit is extended by about 100 cm and from about 2.856 m to about 3 .856m, the second
The line corresponding to the first bit is extended by about 50 cm, increasing this from about 1.428 m to about 1.928 m, and the line corresponding to the first bit does not need to add any delay.

The temporal sequence 7e output from the device according to the invention is in this case approximately 103.7 Mbits / sec (approximately 9.64n) smaller than the bit rate at the input.
s (the reciprocal of the new bit time of s).

In such a case, the duration of the bit experiment may be from about 7.14 ns to about 9.6 in the case of the temporal sequence "1111" in the 4-bit RZ format.
Experimental operation was performed to change to 4n and at a duty cycle of about 0.5 during the input of the device.

FIG. 14 shows the temporal sequence (FIG. 14a) input to the device at about 140 Mbit / s and about 103.7.
FIG. 14 shows a record for a corresponding temporal sequence output from the device at M bits / sec (FIG. 14b), which record is approximately 1 GH
Obtained with a suitable photodetector and oscilloscope with a passband of z. The duration of the bit time output from the device was changed, but the physical duration of the bit remained unchanged, and thus the duty cycle of the bit output from the device was reduced (about 0.37).

Other experiments have shown that the fiber optic lines 910, 920, 930, 9 so that the bit rate of the bits of the spatial image 7d can be changed continuously.
The possibility of continuously changing the length of 40 was shown.

This can be done by the elasticity of the optical fiber, which can be extended by at least about 4% in elastic conditions.

A 10 m optical fiber is rolled, for example, 2
By means of a device capable of extending the optical fiber consisting of a train of pulleys and an electric pulse motor, the optical fiber lines 910, 920, 930, 940 can be extended as much as about 40 cm, whereby the spatial image There is an extra delay of up to about 2 ns between the 7d bits. By using three devices of this type placed in series with respect to the fiber optic lines 910, 920, 930, 940 (the line 910 corresponding to the first bit need not introduce extra delay), a 4-bit It is possible to extend the bit time of the word by no more than about 2/3 ns (thus, the maximum delay corresponding to the fourth bit is about 2 ns). This amount is not significant at low bit rates, but becomes significant at high bit rates. Indeed, for a bit time of about 1 ns (equivalent to a bit rate of about 1 Gbit / s), the device can increase the bit time to about 1.67 ms (about 600 Mbit / s).
(Equivalent to a bit rate of seconds).

In a preferred embodiment, the device according to the invention also comprises means for performing algebraic operations (FIG. 8).

In this case, for example, the fourth CdTe: In
Means (the first and second optical switching modules 2000, 2) capable of converting the 4-bit temporal sequence 7a into the spatial image 7d.
4000), and the four digital optical signals 111, 112, 11 corresponding to the four bits of the spatial image 7d indicated by arrows in FIG.
By optically controlling the polarization state of 3,114, such CdTe: In single crystal 1200 enables algebraic operation.

The above description and comments regarding the first single crystal 200 described above also apply to the fourth single crystal 1200.

It is actually under the action of a continuous voltage V _p ,
And when there is no first light beam that enables the algebraic operation, the fourth single crystal 1200 rotates the polarization plane of the four digital optical signals 111, 112, 113, 114 by about 90 °. Or when illuminated by the first enabling beam, this polarization plane remains unchanged.

The first polarization separator 1210 is arranged downstream of the fourth single crystal 1200. The first polarization splitter 1210 is capable of performing the algebraic operation.
When no light beam is present, the splitter is transparent to the four digital light signals 111, 112, 113, 114 and the first enabling beam is the fourth single crystal 1200. Is illuminated such that the digital optical signal is deflected substantially perpendicular to the direction of incidence.

Thus, as shown in FIG. 8, when there is no optically enabled beam, that is, when no operation needs to be performed, the output from the fourth single crystal 1200 is output. The four digital optical signals 111, 112,
113 and 114 continue their propagation direction. On the other hand, the digital optical signals 111, 112, 113, 114
Means that the first enabling beam is the fourth single crystal 120
When illuminating a zero, ie when an algebraic operation has to be performed, it is deflected in a direction substantially perpendicular to the direction of propagation.

The fifth single crystal 1400 divides the digital optical signals 111, 112, 113, 114 which are deflected by the first polarization separator 1210 by the operation to be performed.
To communicate.

The fifth single crystal 1400 is also actually under the action of the continuous voltage V _p when there is no second light beam enabling the algebraic operation, the four digital light signals 111 , 112, 113, 114 by about 90 °, leaving the plane of polarization unchanged when illuminated by the second enabling beam.

Downstream of the fifth single crystal 1400, a second polarization splitter 1230 is disposed, and when the second enabling beam does not exist, the fourth digital optical signal is output. 111, 112, 11
3, 114 and the second enabling beam is the fifth single crystal 1400
Is oriented so as to be deflected in a direction substantially perpendicular to the incident direction.

Thus, in the embodiment according to FIG. 8, when the second enabling beam is not present, the first mirror 1410 and the second mirror 1420 are output from the second polarization splitter 1230. The digital optical signals 111, 112, 113 and 114 are reflected and these digital optical signals are reflected by a 50/50 beam splitter 115.
Performing a 2 multiplication as represented by 77 in FIG. 8 by leading to 0 and deflecting the 4-bit spatial image 7d to the left. On the other hand, when the second enabling beam illuminates the fifth single crystal 1400, the third mirror 1
430 is the digital optical signal 111, 112, 113, 114 output from the second polarization splitter 1230.
Is reflected to the third polarization splitter 1220. The third polarization separator 1220 further directs the digital optical signals 111, 112, 113, 114 to the 50/50 beam splitter 1150 to deflect the fourth spatial image 7d to the right. Performs the division by two as indicated by 777 in FIG.

After processing, as described above, the spatial image 7d at the output is converted to the processed digital optical signal 9d.
It is reconverted into a temporal sequence 7e of 00 bits.

In another embodiment, the device according to the invention comprises eight optical fibers 11, 12, 13, 14, 15,.
A means (FIG. 9) for performing a symmetric operation on a circular 8-bit spatial image obtained by the collimating means 5 shown in FIG. 10, for example, of the eight digital optical signals output from 16, 17, 18 is included.

Of course, according to a modification not shown, the symmetric operation can also be performed on a spatial image of bits having a linear shape similar to that shown in FIG. 2, for example.

The collimating means 5 comprises a circular set 47 (FIG. 10) of eight collimators 48 (FIG. 10a).
b), wherein the circular set 47 has a maximum diameter of, for example, about 3.6 mm and the collimator 48
Have a diameter of about 1 mm.

At one end of each of the collimators 48, there is a spherical collimation lens 46 having a diameter of about 600 μm.

The coupling between each of the eight optical fibers and each of the spherical collimation lenses 46 has an outer diameter of 1 mm and an inner hole of 126 μm (1 μm larger than the diameter of the cladding of a 1550 nm single mode optical fiber). ) And two wide conical sections at the ends.
It is desirable to be performed by: The two widened cones are connected at one end to one of the eight optical fibers.
At the other end to accommodate and adhere the spherical collimation lens 46 (FIG. 10a).

The focal point of the spherical collimating lens 46 is such that the eight optical fibers can be inserted and glued in contact with the spherical lens 46 without requiring special measures to determine the optimum point of collimation. It is desirable to be placed on a spherical surface.

The eight collimators 48 thus formed are then pre-set, one inside the circular set 47 and the other outside, so as to obtain a substantially regular and symmetrical configuration. It is inserted into a circle between two metal tubes having a defined diameter.

In this case, a suitable device (not shown) capable of converting an 8-bit temporal sequence into a spatial image
The symmetric operation can be performed by the sixth single crystal 1300 arranged downstream of the first single crystal.

As shown in FIG. 9, the sixth single crystal 13
00, under the action of a continuous voltage V _p , said 8 when the light beam 1500 enabling said symmetric operation is not present.
Digital optical signals (corresponding to the 8 bits)
Is rotated by about 90 ° (indicated by the arrow in FIG. 9) and remains unchanged when illuminated by the enabling beam 1500.

The sixth CdTe: In single crystal 1300
A fourth polarization separator 1310 is arranged on the downstream side of
The polarization plane of the digital optical signal is the sixth single crystal 13
When rotated by about 90 ° by 00, ie, when the beam 1500 that enables the symmetric operation is not present, it is oriented to be transparent to the eight digital optical signals. On the other hand, when the plane of polarization is not rotated, that is, when the enabling beam 1500 illuminates the sixth single crystal 1300, the fourth polarization separator 1310 substantially shifts the beam in the direction of incidence. In a direction perpendicular to

Thus, when the beam 1500 enabling the symmetric operation is absent, the eight signals remain unchanged. On the other hand, the enabling beam 15
When the 00 illuminates the sixth single crystal 1300, the λ / 2 plate 1390 performs a required symmetric operation (FIG. 9), eg, symmetric with respect to the bit form axis.
, A prism 1350, a λ / 4 plate 1370,
The mirror 1330 processes the 8-bit circular image.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of an optical device according to the present invention.

FIG. 2 shows the collimation and focusing means of the device shown in FIG.

FIG. 3 illustrates the operation of the optical switching module of the device shown in FIG.

FIG. 4 shows two optical switching devices of the device shown in FIG.
It is a figure showing the operation mode of a module.

FIG. 5 shows an operating mode of a dichroic mirror inserted between two basic modules of the device shown in FIG.

6 shows a means of the optical device shown in FIG. 1 capable of converting an n-bit temporal sequence into a corresponding spatial image.

FIG. 7 is a diagram showing a logical operation of the means shown in FIG. 6;

FIG. 8 is a diagram showing an embodiment of an algebraic operation execution means according to the present invention which can be inserted into an optical device.

FIG. 9 is a diagram showing an embodiment of a symmetric operation execution unit according to the present invention which can be inserted into an optical device.

FIG. 10 is a diagram showing an embodiment of a collimation device for eight digital optical signals of the optical device according to the present invention.

11a shows a graphical representation of a 4-bit signal at the input after a 1-bit removal operation in the device as shown in FIG. 1; FIG. 2b shows a graphical representation of a 4-bit signal in the output after the operation of removing one bit in the device as shown in FIG.

12A is a diagram showing a graphic display of a 4-bit signal at the input after a 1-bit insertion operation in the device shown in FIG. 1; FIG. FIG. 2B is a diagram showing a graphic representation of a 4-bit signal in the output after the 1-bit insertion operation in the device shown in FIG.

13a is a diagram showing a graphical representation of a 4-bit signal at the input after a 4-bit modification operation in the device shown in FIG. 1; FIG. b is a diagram showing a graphical representation of a 4-bit signal in the output after the modification operation in the form of 4-bits in the device shown in FIG. 1;

FIG. 14a shows a graphical representation of a 4-bit signal at the input after a 4-bit bit rate correction operation in the device shown in FIG. 1; FIG. 2b shows a graphical representation of a 4-bit signal at the output after a 4-bit bit rate correction operation in the device shown in FIG.

[Explanation of symbols]

1, 2, 3, 4 Copy of temporal sequence 7 5 Collimating means 6 Digital optical signal 7a, 7b, 7c, 7e Temporal sequence 7d Spatial image 8 Beam splitter 9 Optical means 10 Polarization plane 11, 12, 13, Reference Signs List 14 optical fiber 15, 16, 17, 18 plano-convex lens 20 first polarization analyzer 25 plano-convex lens 31 second multi-mode power optical fiber 32 first multi-mode power optical fiber 33 beam splitter 40 second polarization Analyzer 46 Spherical collimation lens 47 Circular set 48 Collimator 50 Dichroic mirror 60 Laser 70 Third polarization analyzer 71, 72, 73, 74 Light removal signal 80 Collimation means 81, 82, 83, 84 Light insertion signal 90 4 × Between one coupler 101, 102, 103, 104 Triangulation time line 110, 120, 130, 140 Optical fiber 111, 112, 113, 114 Digital optical signal 200 First indium-doped cadmium
Tellurium single crystal (CdTe: In) 310 second light control pulse 320 first light control pulse 321 second light control pulse 400 second indium-doped cadmium
Tellurium single crystal (CdTe: In) 600 word generator 700 polarization plane rotation element 900 processed digital optical signal 910, 920, 930, 940 optical fiber line 1200 polarization plane rotation element 1210, 1220, 1230, 1230 transparent means 1310 transparent Means 1330, 1350 Reflecting means 1400 Polarization plane rotating element 1410, 1420, 1430 Mirror 1500 Light beam 2000 First light switching module 4000 Second light switching module 7000 Third light switching module

 ──────────────────────────────────────────────────の Continuation of front page (71) Applicant 591011856 Pirelli Cavies System e. p. A (72) Inventor Mario Martinelli Milan, Italy, 20097 Sud do Nato Milanese, Via Agadir 16 Bi (72) Inventor Diego Mottarrella Italy 20146 Via Donati, Milan, 2014 14 (72) Inventor David Pickinin Pavia, Italy, 27046 S. Giuletta, Via Case Paradiso 1

Claims (39)

[Claims] 1. An optical device for processing digital optical signals in free space in parallel, comprising: a) an input in guided propagation of a digital optical signal (6) comprising at least one temporal sequence (7a) of n bits. Means (60, 600); and b) at least one temporal sequence (7a) of said digital optical signal (6) each of n bits during guided propagation.
Means for converting into a beam of n digital optical signals (1, 2, 3, 4) comprising: c) in guided propagation said at least one temporal sequence (7a) each of n bits ) Into n beams of digital optical signals (111, 112, 113, 114) into beams of n digital optical signals in free space. D) comprising at least one temporal sequence (7a) of n bits comprising the same information as previously contained in said at least one temporal sequence (7a). The n-bit spatial image (7
d) converting preselected bits from said at least one temporal sequence (7a) of n bits of each of said n digital optical signals (111, 112, 113, 114) in parallel for conversion to d) Means that are selectable in space; e) at least one bit of said spatial image (7d) of n bits can be modified in free space in parallel, at least 1 Optical means selected by a group comprising: means capable of removing bits; means capable of inserting one bit; means capable of modifying the form of at least one bit; f. An output device for the at least one bit of the spatial image (7d) of n bits. 2. The method according to claim 1, wherein the at least one temporal sequence (7a) of n bits is converted to the at least one temporal sequence (7a).
a) each of said n digital optical signals (111, 112, 113, 114) for conversion to said n-bit spatial image (7d) containing the same information previously contained in a) the at least one temporal sequence of n bits (7
a) said optical device capable of selecting preselected bits in parallel in free space from a): a) a first optical switching module (2000);
B) said first optical switching module (200);
0) a second optical switching element arranged in series with respect to
A module (4000); c) said first optical switching module 2000;
And each second optical switching module 40
Means for providing at least one pair of first and second light control pulse beams (320, 320) having a predetermined time interval between each other; d) said at least one pair of first and second light control pulse beams. A dichroic mirror () capable of guiding the first and second optical control pulse beams (320, 321) in a collinear mode with respect to the propagation direction of the n digital optical signals (111, 112, 113, 114) E) the at least one pair of first dichroic mirrors so as to be incident on the dichroic mirror at a pre-established angle.
And a second light control pulse beam (320, 310) for directing collimation means (15, 2
The optical device according to claim 1, further comprising: (5). 3. The first and second optical switching devices.
A module modifies the plane of polarization of the n digital optical signals (111, 112, 113, 114) in free space with the action of the at least one pair of first and second light control pulse beams (320, 310). A first element 200 that can be rotated by a predetermined angle below, and a second element 400 each, and along the respective predetermined plane of polarization, the first element (200) and , And the n digital optical signals (111, 112, 113, 11) output from the second element (400), respectively.
3. The method according to claim 2, further comprising first and second polarization analyzers (20, 40) capable of filtering (4).
An optical device as described. 4. The first and second elements (200, 4).
4. An optical device according to claim 3, wherein (00) comprises first and second indium-doped cadmium tellurium (CdTe: In) single crystals. 5. An optical device according to claim 3, wherein the first and second polarization analyzers (20, 40) are oriented substantially at right angles to each other. 6. The output means comprises a light focusing means (9) capable of guiding the n-bit spatial image (7d) in free space in the waveguide propagation means. The optical device according to any one of 1 to 5. 7. The n output lines (910, 920, 930, 94) capable of timing the n bits of the spatial image (7d) at predetermined time intervals.
The optical device according to any one of claims 1 to 6, wherein the optical device includes (0). 8. An output means for transmitting said n bits to a processed digital optical signal (900) comprising at least one time sequence (7e) of n bits in a timed and guided wave propagation. Optical device according to claim 7, characterized in that it also comprises possible means (90). 9. The n-bit spatial image (7d), wherein the at least one bit of the removing means comprises a third optical switching module (7000) and at least one optical removing signal (71, 72, 73, The optical device according to any one of claims 1 to 8, further comprising means for supplying (74). 10. The system of claim 3, wherein the third optical switching module comprises n number of timed lines (110, 120, 130,
140) and the n digital optical signals (111, 112, 113, 1
An element (700) capable of rotating at least one polarization plane of (14) by a predetermined angle under the action of at least one light removal signal (71, 72, 73, 74);
And the third optical switching module is configured to move the element (70) along a predetermined plane of polarization.
0) output from the n digital optical signals (11
10. Optical device according to claim 9, further comprising a polarization analyzer (70) capable of filtering (1, 112, 113, 114). 11. The method according to claim 11, wherein said element (700) is indium.
The optical device according to claim 10, wherein the optical device is made of a doped cadmium tellurium (CdTe: In) single crystal. 12. The at least one light removal signal (7)
1, 72, 73, 74) output the n digital optical signals (111, 112, 113,...) Output from the n interval timing lines (101, 102, 103, 104).
The optical device according to any one of claims 9 to 11, characterized in that it is collinear with and overlaps only one of the optical devices. 13. The light removal means of the at least one bit of the spatial image (7d) of n bits, downstream of the third optical switching module (7000),
The n digital optical signals (111, 112, 11)
3, 114) and transparent to the at least one light rejection signal (71, 72, 7).
13. The optical device according to claim 9, further comprising a unit capable of reflecting the wavelength of (3, 74). 14. The means capable of inserting at least one bit into the n-bit spatial image (7d) comprises:
At least one optical insertion signal (81, 82, 83, 8
The optical device according to any one of claims 1 to 13, further comprising means for supplying (4) to the first and second optical switching modules (2000, 4000). 15. The at least one optical add signal (8)
15. The optical device according to claim 14, wherein (1, 82, 83, 84) has the same wavelength and power as the optical signal constituting the n-bit spatial image (7d). 16. At least one optical insertion signal (81,
82, 83, 84): {the n digital optical signals (111, 112, 11);
3, 114) and the at least one optical insertion signal (8
15. The method as claimed in claim 14, further comprising means (8) that is transparent to half of the power with (1, 82, 83, 84) and is capable of reflecting the other half of the power. Fifteen
The optical device according to any one of the above. 17. The transparent means (8)
17. The optical device according to claim 16, comprising a 50/50 light beam splitter. 18. The 50/50 optical beam splitter (8), wherein said n digital optical signals (111, 11)
2, 113, 114) and the direction of the at least one optical insertion signal (81, 82, 83, 84) are substantially tilted at an angle of 45 °, and the n digital optical signals (111 , 112, 113, 114) is directed to the at least one optical insertion signal (81, 82, 8).
18. Optical device according to claim 17, characterized in that it is substantially perpendicular to the direction of (3,84). 19. The at least one optical add signal (8)
1, 82, 83, 84),
About 45 ° to 0/50 light beam splitter (8)
And the n digital optical signals (11
1, 112, 113, 114) also comprising means (80) capable of collimating said at least one optical insertion signal (81, 82, 83, 84) in free space so as to overlap one of the ones. 18. The method of claim 17, wherein
19. The optical device according to any one of items 18. 20. At least one optical add signal (81,
20. Light according to any one of claims 14 to 19, wherein the means for supplying (82, 83, 84) also include means for controlling and, if necessary, changing the state of polarization. apparatus. 21. The means for modifying the at least one bit form of the n-bit spatial image (7d) comprises a first and a second beam (320, 310) of the at least one pair of light control pulses. 21. A device as claimed in any one of the preceding claims, comprising means capable of changing the time interval between the first and second beams (320, 310) of the light control pulses of the invention. Light equipment. 22. The n lines (910, 920, 9
30, 940) input at least one bit of the n-bit spatial image (7d) and the at least one output bit is input with respect to the other bits of the n-bit spatial image (7d). 8. The optical device according to claim 7, wherein the time is adjusted by time so that the time is delayed by an amount different from the bit time of (60, 600). 23. The optical device according to claim 1, further comprising means capable of performing an algebraic operation on the n-bit spatial image (7d). 24. The optical device according to claim 1, further comprising means capable of performing a symmetric operation on the n-bit spatial image (7d). . 25. The n bits of the spatial image (7d) output from the first and second optical switching modules (2000, 4000), wherein the means capable of performing the algebraic operation comprises: At least one element (12) capable of rotating the plane of polarization by a predetermined angle under the action of a light laser enabling said algebraic operation.
24. The optical device according to claim 23, further comprising: (00, 1400). 26. The means for performing the operation, comprising: at least one transparent means for at least one first predetermined plane of polarization of the n bits of the spatial image (7d). 1210, 1220, 1230,
26. The method according to claim 23, wherein the transparent means is also capable of deflecting a second plane of polarization substantially perpendicular to the first plane. An optical device according to claim 1. 27. The means for performing the algebraic operation comprises: at least one mirror (141) capable of reflecting the n bits of the spatial image (7d).
The optical device according to any one of claims 23, 25, and 26, further comprising (0, 1420, 1430). 28. The apparatus of claim 28, wherein the means capable of performing the symmetric operation comprises:
The n-bit polarization plane of the spatial image (7d) output from the module (2000, 4000) is transformed under the action of the light beam (1500) enabling the symmetric operation,
The optical device according to claim 24, comprising at least one element (1300) that can be rotated by a predetermined angle. 29. The means capable of performing the symmetric operation comprises at least one of the n bits of the spatial image (7d) being transparent to at least one first predetermined polarization plane. 39. The method of claim 24 or claim 38, further comprising means (1310), wherein said transparent means is also capable of deflecting a second plane of polarization substantially perpendicular to said first plane. The optical device according to any one of the above. 30. The means capable of performing the symmetric operation also comprises means (1330, 1350) capable of reflecting the n bits of the spatial image (7d). The optical device according to any one of claims 24, 28, and 29. 31. The device (1370, 1), wherein said means capable of performing said symmetric operation comprises changing said n-bit polarization state of said spatial image (7d).
390).
0. The optical device according to any one of 0. 32. A method for processing digital optical signals in free space in parallel, comprising: a) sending a digital optical signal (6) comprising at least one temporal sequence (7a) of n bits; b) Converting the digital optical signal (6) into n digital optical signals (1, 2,...), Each of which includes at least one temporal sequence (7a) of n bits in guided propagation;
C) converting the n digital optical signals (1,2,3,4) in guided propagation including said at least one temporal sequence (7a) of n bits each; The beam is converted into n digital optical signals (111, 112, 11) in free space.
3, 114) into a beam; d) the at least one temporal sequence (7) of n bits;
a) into said n-bit spatial image (7d) containing the same information previously contained in said at least one temporal sequence (7a). 112, 113, 114) from said at least one temporal sequence (7a) of n bits in parallel, selecting predetermined bits in free space in said free space. Modifying the at least one bit of the image (7d) in free space in parallel. 33. The method of claim 32, wherein the step of modifying the spatial image (7d) comprises removing at least one bit. 34. The method according to claim 32, wherein the step of modifying the spatial image (7d) comprises inserting at least one bit. 35. A method as claimed in claim 32, wherein the step of modifying the spatial image (7d) comprises modifying a form of at least one bit. 36. The step of modifying the spatial image (7d) comprises moving at least one bit from one location to another in the spatial image (7d). Item 36. The method according to any one of Items 32 to 35. 37. The n-bit spatial image (7d) in a modified free space is reconverted into at least one n-bit temporal sequence (7e) and guided at an output. The method according to any one of 32 to 36. 38. The method according to claim 37, wherein the duration of at least one bit of the n-bit temporal sequence (7e) derived at the output is modified. 39. An optical device for modifying the duration of at least one bit of an n-bit temporal sequence to be converted into a corresponding spatial image (7d), wherein: the n bits of the spatial image (7d) are Guided by a beam of n light guides (910, 920, 930, 940), at the end of which the n bits are further conducted in one light guide (990) in the form of an n-bit time sequence. Waved and ─n light guides (910, 920, 930, 940)
Of the light guides (910, 920, 930, 94) at the input to one light guide (990).
0), wherein one bit moved along the portion of 0) is separated from at least one of the other bits of the temporal sequence by a different time interval than that separated in the initial temporal sequence. Light guide (9
10, 920, 930, 940).