JPH02220037A - Optical flip-flop and optical flip-flop array - Google Patents

Abstract

PURPOSE:To offer the optical flip-flop array which can process many signals at a time without converting a light signal into an electric signal by composing the optical flip-flop of two optical gates which have etalon type optical bistable elements. CONSTITUTION:The couple of optical bistable elements BOD1 and BOD2 are driven with holding light H, and reset light R and set light S to perform flip-flop operation. This optical fli-flop is provided with the two optical gates OG1 and OG2 which have the etalon type optical bistable elements. Namely, the etalon type optical bistable element BOD2 consists of a nonlinear medium layer NL and mirrors M on both sides and the optical bistable element BOD2 is arranged between rod lenses RL2a and RL2b to constitute the optical gate OG2 on the whole. The rod lens RL2a focuses parallel light on the optical bistable element BOD2 and the rod lens RL2b collimates the projection light from the optical bistable element BOD2 into parallel light.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an optical flip-flop and an optical flip-flop array that are driven and controlled by optical signals.

(Prior Art) In the prior art, there is no known device that performs an optical flip-flop operation without performing photoelectric conversion. A configuration shown in FIG. 2 can be considered as a configuration for performing an equivalent operation using conventional technology. That is, each of the optical set pulse S and the optical reset pulse R from the outside is detected by photodetectors DETI and DET2 such as photodiodes, and the respective output signals of these photodetectors DETI and DET2 are sent to signal amplifiers AMI and AM2. amplified by
RS flip-flop EFF composed of electronic circuit
to drive. Furthermore, driver circuits Di and D cause the output signals to cause light emitting elements Ll and L2 such as semiconductor lasers to emit light.
2 to perform an optical foot-flop operation.

Alternatively, as shown in FIG. 3, it is also possible to optically feed back the output to form an optical flip-flop. In the figure, PDa and PDb are photodiodes, L
la, Llb, L2a.

L2b is a light emitting element such as a semiconductor laser, and Rla.

Rlb, R2a, and R2b are adjustment resistors for operating as an optical flip-flop, and HMI to HM4 are half mirrors.

The anode of the photodiode PDa is the light emitting element Ll.
The anode of the light emitting element Lla is connected to one end of the resistor R1a, the cathode of the light emitting element Lla is connected to the DC power supply V-, and the other end of the resistor R1a is grounded. The cathode of the photodiode PDa is connected to the anode of the light emitting element L2g, and also to the DC power supply (+) via the resistor R2a, and the cathode of the light emitting element L2a is grounded. The anode of the photodiode PDb is connected to the anode of the light emitting element L1b and one end of the resistor R1b, and the cathode of the light emitting element Llb is connected to the DC current RV-, and the resistor R1b is connected to the anode of the photodiode PDb.
The other end of 1b is grounded.

The cathode of the photodiode PDb is connected to the anode of the light emitting element L2b, and also to the DC power supply V+ via the resistor R2b, and the cathode of the light emitting element L2b is grounded.

Further, the optical set pulse S is inputted to the photodiode PDb via the half mirror HM2, and the optical reset pulse R is inputted to the photodiode PDb via the half mirror HM4.
is incident on a. The light emitted from the light emitting element Lla is incident on the photodiode PDa, and the light emitted from the light emitting element Llb is incident on the photodiode PDb. The light emitted from the light emitting element L2a passes through the half mirror HMI and becomes a light output Q, and is input to the photodiode I'Db via the half mirror HMI and the half mirror HM2. The light emitted from the light emitting element L2b is transmitted through the half mirror HM3 to become a light output Q', and is also incident on the photodiode PDa via the half mirror HM3 and the half mirror I (M4).

When the optical set pulse S is input to the optical flip-flop having the above-mentioned configuration, the reverse bias current of the photodiode PDb increases, so the light emitting element L2b stops emitting light, and the optical output Q' becomes low level, and the photo Diode P
The intensity of light incident on Da decreases. As a result, the reverse bias current of the photodiode PDa decreases, so that the light emitting element L2a emits light and the optical output Q becomes high level. Since this configuration is symmetrical, the next time the optical reset pulse R is input, the optical output Q becomes low level and the optical output Q' becomes high level.

(Problem to be Solved by the Invention) However, in optical flip-flops according to the prior art, the operating time is determined by the upper limit of the operating speed of the electronic circuit, so the high speed that is the inherent characteristic of light cannot be fully utilized. , it requires optical-to-electrical or electrical-to-optical conversion processing, and has drawbacks such as difficulty in processing a large number of signals at the same time.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide an optical flip-flop that takes advantage of the high-speed nature of light and an optical flip-flop array that can simultaneously process a large number of signals.

(Means for Solving the Problems) In order to achieve the above object, the present invention in claim 1) drives a pair of optical bistable elements with a hold light, a reset light, and a set light to perform a flip-flop operation. In an optical flip-flop, a first optical gate has an etalon-type optical bistable element into which a hold light and a reset light are input, and the state of output light changes depending on the input state of the reset light; Enter the output light of the light gate,
An optical flip-flop was constructed, including a second optical gate having an etalon-type optical bistable element in which the states of transmitted light and reflected light change depending on the incident state of the set light and the emitted light.

Further, in claim (2), an optical flip-flop array consisting of a plurality of optical flip-flops having optical bistable elements includes a plurality of optical gates having etalon-type optical bistable elements; A first method in which a plurality of hold lights and a plurality of reset lights corresponding to each of the plurality of hold lights and a plurality of reset lights are inputted, and the state of the light emitted from the light gate corresponding to the plurality of reset lights changes depending on the incident state of each of the plurality of reset lights. It consists of an optical gate array and a plurality of optical gates each having an etalon-type optical bistable element, and receives a plurality of set lights corresponding to each of the plurality of optical gates and a plurality of output lights of the first optical gate array. , a second optical gate array in which states of transmitted light and reflected light of the optical gate corresponding to the set light or the emitted light change depending on the incident state of the set light and the emitted light. was configured.

(Function) According to claim (1) of the present invention, for example, when the hold light is always input to the first light gate and the reset light is input to the first light gate, the reset light is input to the first light gate. The light incident on the optical bistable element of the first optical gate will be at a high level, and the light transmittance of the optical bistable element will increase. Thereby, in the first optical gate, the hold light passes through the optical bistable element without being attenuated, so that the reflected light of the hold light by the optical bistable element is attenuated. Furthermore, when the reset light is no longer incident, the light transmittance of the optical bistable element decreases, and the hold light is reflected by the optical bistable element.

Here, if the reflected light of the hold light emitted from the first light gate is incident on the second light gate, when the reset light is incident on the first light gate, the second light gate The incident light on the optical bistable element becomes low level, and the light reflectance of the optical bistable element increases. Furthermore, even after the input of the reset light to the first optical gate is cut off, the optical reflectance of the optical bistable element of the second optical gate is maintained in an increased state. The reflected light of the hold light emitted from the first light gate is reflected by the optical bistable element of the second light gate, and this state is maintained.

After this, when the set light is incident on the second optical gate, the incident light on the optical bistable element of the second optical gate becomes high level, and the optical reflectance of the optical bistable element decreases. , the reflected light of the hold light emitted from the first optical gate enters the optical bistable element, passes through the optical bistable element of the second optical gate without attenuation, and is set. This state is maintained even after the incidence of light is cut off. This results in a free-knob flop operation.

According to claim (2), when the hold light corresponding to the plurality of optical gates of the first optical gate array is always incident on each of the plurality of optical gates, for example, the first
When the reset light corresponding to the first optical gate of the optical gate array is incident on the first optical gate array, the incident light on the optical bistable element of the first optical gate becomes high level,
The light transmittance of the optically bistable element increases. Thereby, in the first optical gate of the first optical gate array into which the reset light is incident, the hold light is transmitted through the optical bistable element with almost no attenuation, so that the hold light is transmitted by the optical bistable element. The reflected light of is attenuated. In addition, the first
When the reset light is no longer incident on the optical gate, the light transmittance of the optical bistable element decreases, and the hold light is reflected by the optical bistable element.

Here, the first light emitted from the first light gate array
When the reflected light of the hold light by the light gate is incident on the first light gate of the corresponding second light gate array, the reset light is applied to the first light gate of the first light gate array. When incident, the incident light on the optical bistable element of the first optical gate of the corresponding second optical gate array will be at a low level, and the optical reflectance of the optical bistable element will increase. Furthermore, even after the input of the reset light to the first optical gate of the first optical gate array is cut off, the light of the optical bistable element of the first optical gate of the corresponding second optical gate array is Since the reflectance is maintained in an increased state, the reflected light of the hold light by the first light gate, which is emitted from the first light gate array and can enter the optical bistable element, is reflected by the corresponding second light. It is reflected by the optical bistable element of the first optical gate of the gate array and this state is maintained.

After this, when the set light is incident on the first optical gate of the second optical gate array, the incident light on the optical bistable element of the first optical gate becomes high level, and the optical bistable element The light reflectance of the light reflected by the first light gate of the first light gate array, which is emitted from the first light gate array and enters the optical bistable element, is greatly reduced. The set light is transmitted through the optical bistable element of the first light gate of the corresponding second light gate array without attenuation, and the incidence of the set light to the first light gate of the second light gate array is cut off. This state is maintained even after This allows multiple flip-flop operations to be performed independently.

(Embodiment) FIG. 1 is a block diagram showing a first embodiment of the present invention. In the figure, F is a single mode optical fiber (hereinafter simply referred to as an optical fiber), FCMI a-FCMld is a fiber collimator, and HMI and HM2 are half mirrors. In addition, PBSI to PBS3 are polarizing beam splitters that transmit linearly polarized light with a horizontal polarization plane, QPLI and QPL2 are quarter-wave plates, RLI, RL2a, RL2b, and RL3 are rod 1/ns, and BODI and BOD2 are optical bistable. Motoko, OG
1 and OG2 are optical gates, sp is a light shielding plate, and LA is a semiconductor laser. The input lights are a set light S, a reset light R, and a steady hold light H. The set light S and the reset light R are non-polarized, and the hold light H is connected to the semiconductor laser LA so that its polarization plane is horizontal. is generated by

The reset light R is made to enter the polarizing beam splitter PBSI via the optical fiber F1 fiber collimator FCM1a. Furthermore, hold light H emitted from the semiconductor laser LA is incident on the light incidence side of the polarization beam splitter PBSI orthogonal to the reset light R via a rod lens RL3. The combined light of the reset light R and the hold light H emitted from the polarizing beam splitter PBSI is reflected by the half mirror HMI and enters the optical bistable element BODI via the rod lens RLI of the optical gate OGI.

In addition, the light that enters the half mirror HMI from the side of the optical gate OG1 and passes through the half mirror HMI passes through the polarizing beam splitter PBS2 and the quarter-wave plate QPLI and enters one end side of the optical gate OG2. , and further enters the optical bistable element BOD2 via the rod lens RL2a. The light emitted from the other end of the optical gate OG2 is sent to the polarizing beam splitter P via the quarter-wave plate QPL2.
The light incident on BS3 and reflected by the polarizing beam splitter PBS3 is output as optical output Q to the optical fiber F via the fiber collimator FCM1d.

A quarter wavelength plate Q is attached to the polarizing beam splitter PBS2.
incident from the PLI side, and the polarizing beam splitter P
The light reflected by BS2 in a direction perpendicular to the incident direction is sent to a polarizing beam splitter PBSI and a light shielding plate SP.
The light is incident on the half mirror HM2 which is arranged in parallel.

Half mirror H from the polarizing beam splitter PBS2 side
The light incident on M2 and reflected by half mirror HM2 is emitted to optical fiber F as optical output Q' via fiber collimator FCM1c. Also, set light S
is incident on the optical gate OG2 via the optical fiber F5 fiber collimator FCM1b, the half mirror HM2, the polarizing beam splitter PBS2, and the quarter-wave plate QPL1.

FIG. 4 is an enlarged view of the optical gate OG2 in the configuration example of FIG. 1. M is a mirror, NL is a nonlinear medium layer, and the nonlinear medium layer NL and the mirrors M on both sides constitute an etalon type optical bistable element BOD2, and the rod lenses RL2a, RL2
An optical bistable element BOD2 is placed between the two sides of the optical gate OG2, thereby configuring the optical gate OG2 as a whole. Rod lens RL2a
is such that parallel light is focused on the optical bistable element BOD2, and the rod lens RL2b is the optical bistable element BOD2.
Each type uses one in which the light emitted from it becomes parallel light.

Next, a method for creating this optical gate OG2 will be explained.

First, A and QGa were placed on a separately prepared GaAs substrate.
As was added for 0.2 μms, then 75AO, 330, 87A, 17GaAs layer and 75A GaAs layer.
100 layers of 0.33 and 0.87 are stacked alternately. This GaAs and Ap
The part where GaAs is alternately laminated is 0.33
0.87 So-called M Q W (Multfpfe Quantu
m Well), the nonlinear medium layer NL in this configuration is
becomes. Then, 97A Tie” layer and 150A S
Eight iO layers are alternately stacked to form a mirror M with a reflectance of 98% on one side. The mirror M on one side and the nonlinear medium layer N
Place the stacked GaAs substrate L on the rod lens RL2a with the side with the mirror M facing down! do.

Next, the excess GaAs substrate is etched, and the Ail GaAs layer with a thickness of 0.2 μm, which is a protective layer, is exposed.
．． 33 0.87 Let it come out. On top of this, eight 97A T l 02 layers and 150A S I O2 layers are alternately laminated to form the mirror M on the opposite side. Furthermore, the rod lens RL2a is glued to another prepared rod lens RL2b so that its optical axis is aligned with the rod lens RL2b, thereby completing the optical game OG2. The operating wavelength in this case is 0.87 μm. light gate OG1
The manufacturing method is also similar.

The optical gate OG2 produced in this way. An optical flip-flop can be constructed by bonding each optical component as shown in FIG. 1 before and after OG1 so that their optical axes coincide.

In addition, in the example of Mizui 1, the mirror M is TiO2/S
Although it was constructed using an iO2 dielectric multilayer mirror, it is not limited to this, and Zn5e/NaF
・Dielectric multilayer mirror such as a combination of 3A, 9 F3 or Cr, Aj7. Needless to say, it can be constructed using metals such as Au and Ag, or composite films thereof. In addition, although the nonlinear medium layer NL is formed of GaAs/AJ2GaAs-based material, it is not limited to this.
MQW, GaA, combinations of InAs/A, QInAs, etc.
■-V group compound semiconductors such as s, InP, InSb, InAs, ■-■ group compound semiconductors such as Zn5e, ZnS, CdS, CdTe, Te, CdHgTe, CuC,
Semiconductors such as 17, CdS Se etc. 1-x
Semiconductor-doped glass, polydiacetylene, made by dispersing fine particles of X semiconductor with a diameter of about 100A in glass;
It goes without saying that it can be constructed using an organic material with a large nonlinear constant, such as 2-methylene or 4-nitroaniline.

Figure 5 shows the incident light intensity vs. reflected light intensity characteristics of the optical bistable element BODI, Figure 6 (a) shows the incident light intensity vs. transmitted light intensity characteristics of the optical bistable element BOD2, and Figure 6 (b) shows the incident light intensity vs. reflected light intensity characteristics of the optical bistable element BODI. The incident light intensity-return light intensity characteristics of the optical bistable element BOD2 are shown, as well as the setting ratio of the incident light intensity for operation as an optical flip-flop.

In FIG. 5, the horizontal axis represents the incident light intensity Pin, and the vertical axis represents the reflected light intensity Pr. In addition, PO is the bistable threshold of the optical bistable element BOD1, H is the optical intensity of the steady hold light, T1 is the optical intensity of the reset light, and Prhl is the reflection of the optical bistable element BOD1 against the hold light in a high reflection state. The light intensity Pr, 91 is the reflected light intensity of the optical bistable element BODI in a low reflection state with respect to the combined light of the hold light and reset light. The optical bistable element BODI enters a low reflection state when the incident light intensity exceeds its bistable threshold PO, and enters a high reflection state when it is lower than the bistable threshold PO.

In FIG. 6(a), the horizontal axis represents the incident light intensity Pin, and the vertical axis represents the transmitted light intensity Pt.

In FIG. 6(b), the horizontal axis represents the incident light intensity P1n, and the vertical axis represents the reflected light intensity P''.
) and FIG. 6(b), P3. P4 is the bistable threshold of the optical bistable element BOD2, PrR1 is the reflected light intensity for the combined light of the hold light and reset light when the optical bistable element BODI is in a low reflection state as described above, and Prh
1 is the reflected light intensity with respect to the hold light when the optical bistable element BOD1 is in a high reflection state. In addition, T2 is the light intensity of the set light, Pth2 is the transmitted light intensity in the optical bistable element BOD2 when the incident light has light intensity Prhl in the high transmission state (-low reflection state), and pth2'' is the light intensity in the high transmission state. The transmitted light intensity for the set photon reflected light intensity Prhl of the optical bistable element BOD2, Ptj!2 is the light intensity Prhl of the incident light in the low transmission state (-high reflection state).
The transmitted light intensity when Pt,I)2- is the transmitted light intensity when the incident light in the low transmission state has a light intensity PrfIl. Further, Pr h2 is the reflected light intensity when the incident light in the high reflection state has the light intensity Prhl, and Prh2- is the reflected light intensity when the incident light in the high reflection state has the light intensity Pr.
11, PrfI2 is the reflected light intensity when the incident light in the low reflection state has a light intensity Prh of 1, PrJ72- is the set photon reflected light intensity Prhl of the optical bistable element BOD2 in the low reflection state. is the reflected light intensity for

The optical bistable element BOD2 enters a low reflection state when the incident light intensity P1n exceeds its bistable threshold P4, and enters a high reflection state when it is lower than the bistable threshold P3.

In the embodiment of Section 1, the sum of the light intensity H of the hold light and the light intensity T1 of the reset light is greater than the bistable threshold PO, and the light intensity H of the hold light is smaller than the bistable threshold PO. , Furthermore, the sum of the reflected light intensity Prhl and the light intensity T2 of the set light is larger than the bistable threshold P4, and the reflected light intensity Prhl is smaller than the bistable threshold P4, and the bistable threshold Each incident light intensity is set so that the reflected light intensity Prj71 becomes larger than P3 and the reflected light intensity Prj71 becomes smaller than the bistable threshold P3.

Next, the operation of the first embodiment having the above-described configuration will be explained based on FIGS. 7(a) and 7(b). In the figure, P
1nl and P ln2 are optical bistable elements B, respectively.
Indicates the light intensity incident on ODI and BOD2, Pout
l is transmitted through the optical bistable element BOD2, and the quarter-wave plate Q
PL2 shows the light intensity emitted to the optical fiber F via the polarizing beam splitter PBS3 and the fiber collimator FCM1d, Pout2 is reflected by the optical bistable element BOD2, and is reflected by the quarter-wave plate QPLI, the polarizing beam splitter PBS2, and the half mirror. -The intensity of light emitted to the optical fiber F via HM2 and the fiber collimator FCM1c is shown.

For example, assume that the initial state is that Pout 1 (Q) is at high level and Pout 2 (Q-) is at low level. Here, when the reset light R is incident with light intensity T1, the linearly polarized component of the reset light R whose polarization plane is perpendicular is combined with the hold light H by the polarizing beam splitter PBS1, and this combined light is incident on the half mirror HMI. The light is reflected by the half mirror HMI and enters the optical bistable element BODI. As a result, the optical bistable element BODI changes from a high reflection state to a low reflection state after the switching time has elapsed, and the intensity of light P 1n2 incident on the optical bistable element BOD2 decreases accordingly. This value is the bistable threshold P3
After the switching time has elapsed, the optical bistable element BOD2 changes to a high reflection state.

After that, when the incidence of the reset light R is cut off, the optical bistable element B
OD1 changes to a high reflection state after the switching time has elapsed. As a result, the hold light H is reflected by the optical bistable element BODI, passes through the half mirror HMl, the polarizing beam splitter PBS2, and the quarter-wave plate QPLI, and enters the optical bistable element BOD2. The incident light at this time is circularly polarized by the quarter wavelength plate QPL1.

Further, since the light intensity Prhl of the light incident on the optical bistable element BOD2 at this time is between the bistable thresholds P3 and P4, the optical bistable element BOD2 maintains a high reflection state. As a result, the reflected light intensity Pou by the optical bistable element BOD2
t 2 (Q ”) becomes a high level, and the transmitted light intensity Pout 1 (Q) of the optical bistable element BOD2 becomes a low level. In this state, the set light S is changed to a light intensity T
2, the set light S passes through the half mirror HM2 and enters the polarizing beam splitter PBS2. Furthermore, the polarizing beam splitter PB82 combines the reflected light from the optical bistable element BODI, and the quarter-wave plate QPL
The light is incident on I, is circularly polarized by the quarter-wave plate QPLI, and is incident on the optical bistable element BOD2. As a result, the optical bistable element BOD2 changes from the high reflection state to the low reflection state after the switching time has elapsed, and the optical bistable element BOD
The transmitted light intensity Pout 1 (Q) of 2 becomes a high level, and the reflected light intensity Pout 2 (Q −) becomes a low level. Here, the optical output Q from the fiber collimator FCM1d is the quarter-wave plate QPL1. QPL2 and polarizing beam splitter PBS2. Due to the PBS3, only the hold light H component is present. After this, when the incidence of the set light S is cut off, the intensity of the light incident on the optical bistable element BOD2 decreases, but since this incident light has a light intensity Prhl greater than the bistable threshold P3, Stable element BOD2 maintains a low reflection state.

The input/output relationship described above is the same as that of an RS flip-flop in an electric circuit.

FIG. 8 is a block diagram showing a second embodiment of the present invention. In the figure, F is a single mode optical fiber, F CM
1 a = F CM 1 e is a fiber collimator, MPI is a composite prism having reflective mirrors Mla and Mlb inside, MP2 is a composite prism having a reflective mirror M2a inside, and OGI and OG2 are optical gates.

The optical gates OGI and OG2 are created in the same manner as in the first embodiment described above. Here, the rod lenses RL1a, R
L1b, RL2a, and RL2b have a squared refractive index distribution in the radial direction, and have end faces perpendicular to the optical axis. In addition, the optical bistable element BODI of the optical gates OGI and OG2.

BOD2 has the same characteristics as the first embodiment. The input lights are a set light S, a reset light R, and a steady hold light H. 7 The difference between the second embodiment and the first embodiment is that the hold light H and the reset light R are respectively incident on opposite sides of the optical bistable element BOD1, and the hold light H by the optical bistable element BOD1 is The reflected light and the set light S are respectively incident on opposite sides of the optical bistable element BOD2, and the respective light components are separated by shifting the axis of the optical system. This axis-shifting optical system includes rod lenses RL1a and RL1b having a squared refractive index distribution.
, RL2a, RL2b, and the rod lens RL1a parallel to the axis.

All the light incident on the end faces on one end side of RLlb, RL2a, and RL2b is condensed at the center (-axis center) of the end face on the other end side. That is, guiding the optical fiber F,
The reset light R made into parallel light by the fiber collimator FCM1a is sent to the optical bistable element B by the rod lens RL1a.
The light is focused at the center of one side of the ODI. In addition, the hold light H guided through the optical fiber F and made into parallel light by the fiber collimator FCM1b is transmitted through the composite prism MPI,
The rod lens RL1b focuses the light onto the center of the other surface of the optical bistable element BOD1. Furthermore, the optical bistable element BO
The hold light H reflected by the DI passes through the composite prism MP
After being reflected by the reflecting mirrors Mla and Mlb of the optical system OG2, the light is focused onto the center of one surface of the optical bistable element BOD2 by the rod lens RL2a of the optical game OG2. At this time,
When the hold light H is reflected by one surface of the optical bistable element BOD2, this hold light H is transmitted through the composite prism MP1 and is emitted to the optical fiber F as a light output Q' via the fiber collimator FCM1c. .

Further, when the hold light H passes through the optical bistable element BOD2, this transmitted light is incident on the reflecting mirror M2 of the composite prism MP2 by the rod lens RL2b, and after being reflected by the reflecting mirror M2, the fiber collimator FCM1
The light is emitted to the optical fiber F as a light output Q via the light source d.

Furthermore, the optical fiber F is guided, and the fiber collimator FC
The set light S made into parallel light by M1e is a composite prism MP
2, and is focused by the rod lens RL2b onto the center of the other surface of the optical bistable element BOD2.

In addition, each of the above-mentioned components includes the optical path of the reset light R that has passed through the optical bistable element BODI, the optical path of the hold light H that is incident on the optical bistable element BODI, and the optical path of the optical bistable element BODI.
so that the optical path of the hold light H reflected by the optical bistable element BOD2 does not match, and the optical path of the set light S transmitted through the optical bistable element BOD2 does not match the optical path corresponding to the optical output Q'.
Furthermore, the arrangement is such that the optical path of the set light S reflected by the optical bistable element BOD2 and the optical path corresponding to the optical output Q do not coincide.

The operation of the embodiment of this section 2 with the above-mentioned configuration is similar to that of the first embodiment, but since the above-mentioned axis-shifting optical system is configured, polarizing beam splitters, quarter-wave plates, etc. This eliminates the need for a configuration with less loss. In addition, the degree of freedom in setting the optical system increases, that is, it becomes possible to easily adjust the position and attach the fiber collimator.
Flip-flop operation can be easily performed.

Incidentally, as in the first embodiment, a semiconductor laser that generates the hold light H may be incorporated.

FIG. 9 is a configuration diagram showing a third embodiment of the present invention. In the figures, the same components as those in the first embodiment are represented by the same reference numerals. That is, PBS 1 to PBS 3 are polarizing beam splitters that transmit linearly polarized light with a horizontal polarization plane, HMI,
HM2 is a half mirror QPLl, QPL2 is a quarter wavelength plate, MLAl, MLA2a, MLA2b are microlens arrays, and BODI and BOD2 are optical bistable elements.

The microlens array MLAI and the optical bistable element BO
D1 constitutes an optical gate array 0G10, and microlens arrays MLA2a, MLA2b and light stabilizing element BOD2 constitute an optical gate array 0G20.

The reset light R and hold light H corresponding to each optical gate of the optical gate array 0GIO are sent to the polarization beam splitter PB.
They are incident on the SI so as to be orthogonal to each other. Further, after being combined by a polarizing beam splitter PBSI, it is reflected by a half mirror HMI and is incident on each optical gate of the optical game h'7 ray 0GIO. In addition, the light reflected by each optical gate of the optical gate array 0GI0 and transmitted through the half mirror HMI is sent to the polarizing beam splitter PBS.
The light passes through the wavelength plate QPLI and the quarter-wave plate QPLI, and enters one end of the optical gate of the corresponding optical gate array 0G20. The light emitted from the other end of each optical gate of the optical gate array 0G20 is incident on the polarizing beam splitter PBS3 via the quarter-wave plate QPL2, and the light reflected by the polarizing beam splitter PBS3 is transmitted to each optical gate. It is emitted as an optical output Q corresponding to .

The reflected light from each optical gate of the light incident on one end side of each optical gate of the optical gate array 0G20 is reflected by the polarizing beam splitter PBS2, and is reflected by the half mirror HM2.
It is further reflected by the half mirror HM2, and is emitted as an optical output Q' corresponding to each optical gate of the optical gate array 0G20. In addition, optical gate array 0G
The set light S corresponding to each of the 20 light gates is a half mirror.
After passing through HM2, it is reflected by polarizing beam splitter PBS2, passes through quarter-wave plate QPL2, and enters one end of each optical gate of optical gate array 0G20.

Figure 10 is an enlarged view of the part marked ■ in Figure 9, with ML2
a and ML2b each indicate one microlens.

The above configuration is equivalent to a plurality of optical bistable elements arranged two-dimensionally in parallel, and a plurality of optical flip-flops are spatially integrated. The operation of each optical flip-flop is the same as in the first embodiment described above.

(Effect of the invention) As explained above, according to claims (1) and (2), since the optical signal is controlled by the optical signal without converting the optical signal into an electrical signal, It becomes possible to take full advantage of a certain high speed.

Moreover, by integrating the optical parts and making it modular, there are advantages such as ease of handling and easy integration into other devices.

Further, by applying the optical flip-flop and optical flip-flop array according to each claim, 1. a counter;
It is also expected that electronic circuits such as comparators can be constructed from optical circuits.

Furthermore, according to claim (2), in addition to the above effects, it becomes possible to simultaneously and independently process a plurality of optical signals by utilizing the two-dimensionality of the Fabry-Perot structure.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a first embodiment of the present invention, FIG. 2 is a diagram showing a first conventional example, FIG. 3 is a diagram showing a second conventional example, and FIG. 4 is a diagram similar to that shown in FIG. Fig. 5 is an incident light intensity-transmitted light intensity characteristic diagram of the optical bistable element, Fig. 6(a) is an incident light intensity-transmitted light intensity characteristic diagram of the optical bistable element, Fig. 6 (b
) is an incident light intensity-reflected light intensity characteristic diagram of an optical bistable element, FIGS. 7(a) and 7(b) are explanatory diagrams of flip-flop operation in the embodiment, and FIG. FIG. 9 is a block diagram showing a third embodiment of the present invention, and FIG. 10 is a partially enlarged view of the third embodiment. HMI, HM2...half mirror-PBSI, PBS2
．． PBS3...Polarizing beam splitter, F...Single mode optical fiber, FCMI a-FCMle...
・Fiber collimator, LA...semiconductor laser, QP
LI, QPL2...quarter wave plate, OGl. OG 2-...Optical gate, RLI, RL2a, RL2b
. RL3...Rod lens, BODI, BOD2...
Light, - bistable element, 0GIO, 0G20... optical gate array, MLA1, MLA2a,
M L A 2 b-v Micro Lens Array, NL・
...Nonlinear medium, M...Mirror MPI, MP2...
Composite prism. Patent applicant Nippon Telegraph and Telephone Corporation

Claims (2)

[Claims] (1) In an optical flip-flop that performs flip-flop operation by driving a pair of optical bistable elements with a hold light, a reset light, and a set light, the hold light and the reset light are input, and the output light changes depending on the incident state of the reset light. A first light gate having an etalon-type optical bistable element that changes the state of the set light and the output light of the first light gate is input, and depending on the incident state of the set light and the output light, transmitted light and 1. An optical flip-flop comprising: a second optical gate having an etalon-type optical bistable element that changes the state of reflected light. (2) In an optical flip-flop array consisting of a plurality of optical flip-flops having an optical bistable element, the array comprises a plurality of optical gates having an etalon-type optical bistable element, and a plurality of optical gates corresponding to each of the plurality of optical gates a first optical gate array into which a hold light and a plurality of reset lights are incident, and a state of output light from a light gate corresponding to the plurality of reset lights changes depending on an incident state of each of the plurality of reset lights; and an etalon; It is made up of a plurality of light gates each having a type optical bistable element, and a plurality of set lights corresponding to each of the plurality of light gates and a plurality of output lights of the first light gate array are input, and the set light and the light emitted from the first light gate array are input. an optical flip-flop array comprising: a second optical gate array in which states of transmitted light and reflected light of the optical gate corresponding to the set light or the emitted light change depending on the incident state of the emitted light; .