JP5944849B2 - Optical signal buffer memory circuit - Google Patents

Description

  The present invention relates to optical communication, optical processing, and an optical signal buffer memory circuit in an optical computer.

  As typical methods for realizing the optical signal buffer, the following methods have been proposed.

[First prior art]
In the first method, as shown in FIG. 6, a plurality of optical delay optical waveguides ODL-1 to ODL-N having different lengths are prepared, and the optical delay optical waveguides ODL-1 to ODL-N are prepared. An optical switch OS-1 is disposed at the input end, and an optical multiplexer OC-1 is disposed at the output end. An optical signal input from the input port P-OP-In is optically delayed as a propagation path using the optical switch OS-1. By switching between the optical waveguides ODL-1 to ODL-N, a function as a buffer memory is realized by a method of giving a desired optical delay and outputting from the output port P-OP-Out.

  In this first method, delays other than the optical delay optical waveguides ODL-1 to ODL-N prepared in advance cannot be applied, and the optical switch OS-1 can be used for switching. Because there is a limit to the number of optical propagation paths (the current commercial product is about tens of times, and there is another problem that the insertion optical loss increases as the switchable number increases). Only an extremely limited optical buffer memory can be realized with respect to the storage time of the column, and as the pattern of the switchable optical delay amount increases, the optical circuit becomes larger.

[Second prior art]
The second method uses an optical circuit as shown in FIG. 7 to store a stored optical data signal string input from an input port P-OP-In in a fiber loop or an optical waveguide loop O-Loop. A desired optical delay is obtained by rotating the optical amplifier OA while performing propagation loss compensation and the like, extracting it as an optical data signal sequence at a desired timing by the optical switch OS-2, and outputting it from the output port P-OP-Out. To realize the function as an optical buffer memory.

  This method was devised in the hope that it can overcome the problem of the first method, “As the pattern of switchable optical delay amount increases, the optical circuit becomes larger.” In this second method, as the number of times the optical data signal train is circulated increases, the propagation loss of the optical waveguide loop O-Loop for circulation is compensated. The optical waveform of the optical data signal train gradually collapses due to the influence of mixed noise such as ASE (Amplified Spontaneous Emission) from the optical amplifier OA, the influence of dispersion of the optical waveguide loop O-Loop, etc. It is known that it is difficult to maintain a data signal longer than the number of laps (see Non-Patent Document 1).

R. Langenhorst et al, "Fiber Loop Optical Buffer," JOURNAL OF LIGHT WAVE TECHNOLOGY, IEEE, 1996, VOL. 14, NO.3, pp. 324-335 Q. Lai, et al., "Low-Power Compact 2x2 Thermooptic Silica-on-Silicon Waveguide Switch with Fast Response," IEEE PHOTONICS TECHNOLOGY LETTERS, MAY 1998, VOL. 10, NO.5, pp. 681-683 S. Diez, et al., "160Gbit / s all-optical demultiplexer using hybrid gain-transparent SOA Mach-Zehnder interferometer," ELECTRONICS LETTERS, 17 AUGUST 2000, Vol. 36, No. 17, pp. 1484-1486 T. Ito, et al., "Bit-rate and format conversion from 10-Gbit / s WDM channels to a 40 ^ Gbit / s channel using a monolithic Sagnac interferometer integrated with parallel-amplifier structure," IEE Proc.-Optoelectron. , February 2004, Vol. 151, No. 1, pp. 41-45 H. Nakamura, et al., "Ultra-fast photonic crystal / quantum dot all-optical switch for future photonic networks," Optics Express, 2004, Vol. 12, No. 26, pp. 6606-6614

  An object of the present invention is to provide an optical signal buffer memory circuit in an optical communication, optical processing, and optical computer, which can be output with an optical delay of an arbitrary integral multiple of the stored optical signal length, and As in the optical buffer memory described in [First Prior Art], there is no “larger optical circuit as the pattern of adjustable optical delay amount increases” and [first As in the optical buffer memory described in the “2 Prior Art”, it is accompanied by the influence of mixed noise such as ASE from the optical amplifier for loss compensation used in the optical buffer memory circuit or the optical waveguide in the optical buffer memory circuit. An optical signal that, in principle, can provide an infinite amount of optical delay by overcoming the “applicable optical delay limit due to optical signal waveform degradation due to the effects of dispersion effects, etc.” To provide a buffer memory circuit.

  That is, an object of the present invention is to provide an optical signal buffer memory circuit capable of providing an infinite optical delay amount with a simple configuration without causing waveform deterioration.

An optical signal buffer memory circuit of the present invention that solves the above problems is as follows.
An external optical input port P-OCLK-In for inputting the clock signal light CLK-1 output from the clock signal light source, and an optical output port located on the bar side with respect to the external optical input port P-OCLK-In Two optical interference arms having P-MZ-1-bar and an optical output port P-MZ-1-cross located on the cross side, and the optical interference arm located on the optical waveguide of one of the optical interference arms Optical phase modulation means L1-1 for modulating the phase of the optical signal train propagating through the inside, and the phase of the optical signal train propagating through the optical interference arm located on the optical waveguide of the other optical interference arm Mach-Zehnder interference type light intensity modulation means MZ-1 which has an optical phase modulation means R1-1 for applying modulation to the light and functions as a Mach-Zehnder type interferometer,
An optical waveguide 18 directly or indirectly connected to an external optical input port P-Data-In for inputting an optical signal sequence Data-1 having information to be stored, and guiding the optical signal sequence Data-1.
An optical input port P-C1-1 connected to the optical waveguide 18 to which an optical signal string Data-1 from the external optical input port P-Data-In is input, and the optical output port P-MZ-1-bar Or P-C1-2 to which an optical signal train from any one of the optical output ports P-MZ-1-cross is input, and optical output ports P-C1-3, P-C1-4, Optical branching unit C-1 for branching and outputting the optical signal train input from the optical input ports P-C1-2 and P-C1-1 to the optical output ports P-C1-3 and P-C1-4 When,
An optical waveguide 14 that guides an optical signal train from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross to the optical input port P-C1-2;
The light from the optical output port P-C1-4 connected to the optical input port P-R1-1 for inputting the optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means R1-1. An optical waveguide 15R for guiding the signal train;
Light from the optical output port P-C1-3 connected to the optical input port P-L1-1 for inputting the optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means L1-1. An optical waveguide 15L for guiding the signal train;
The optical signal trains provided on the optical waveguide 15L or the optical waveguide 15R and simultaneously output from the optical output ports P-C1-3 and P-C1-4 are the optical input ports P-L1-1 and P-. An optical waveguide section DD-1 that generates an optical delay for adjusting the timing of reaching R1-1 to be greater than or equal to the pulse width of the clock signal light CLK-1 and less than the pulse repetition period;
With
As the clock signal light CLK-1, RZ (Return to Zero) type signal light is inputted from the external light input port P-OCLK-In,
When the optical signal string Data-1 synchronized with the clock of the clock signal light CLK-1 is input from the external optical input port P-Data-In, first, the input optical signal string Data-1 is changed. The phase modulation means R1-1 and L1-1 are driven to cause a phase difference in the clock signal light CLK-1 propagating through the two optical interference arms, and the clock signal light An optical signal train CLK output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross by turning on or off each pulse of CLK-1. -1-out-DMZ1 is circulated to the optical branching unit C-1 as the same data pattern as the data pattern of the optical signal sequence Data-1.
Subsequent rounds use the previous round optical signal sequence CLK-1-out-DMZ1 output from the optical output port P-MZ-1-bar, and the phase modulation means R1-1, L1-1. To cause a phase difference in the clock signal light CLK-1 propagating in the two optical interference arms, and to turn on or off each pulse of the clock signal light CLK-1. The optical signal train CLK-1-out-DMZ1 of the circumference output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross is As a data pattern identical to the data pattern of the signal sequence Data-1, the optical branching unit C-1 circulates and maintains the data pattern in the circuit,
The optical branching section C-1
A first multimode interference waveguide section having two optical input ports and two optical output ports;
A second multimode interferometric waveguide section having two optical input ports and two optical output ports;
Two optical waveguides respectively connecting two output ports of the first multimode interference waveguide section and two optical input ports of the second multimode interference waveguide section;
An optical phase adjusting unit arranged in at least one of the two optical waveguides to adjust the phase of light propagating through the waveguide.

The optical signal buffer memory circuit of the present invention is
Further, on the optical waveguide of one of the optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-1, located in the rear stage side of the optical phase modulation means L1-1 and passing through the optical interference arm. Optical phase modulation means L1-2 for modulating the phase of the propagating optical signal train;
It is located on the optical waveguide of the other optical interference arm of the Mach-Zehnder interference type optical intensity modulation means MZ-1, and is located behind the optical phase modulation means R1-1 and propagates through the optical interference arm. Optical phase modulation means R1-2 for modulating the phase of the optical signal train;
An external optical input port P-FF-In for inputting an optical signal sequence FF-1 for flip-flop control of the data pattern maintained in the circuit;
An optical input port P-C3-2 and optical output ports P-C3-3, P-C3-4, and the optical signal train FF-1 input from the external optical input port P-FF-In An optical branching unit C-3 for inputting from the optical input port P-C3-2 and branching out to the optical output ports P-C3-3 and P-C3-4;
An optical waveguide 21 for guiding the optical signal string FF-1 from the external optical input port P-FF-In to the optical input port P-C3-2;
The light from the light output port P-C3-4 connected to the light input port P-R1-2 for inputting the light signal sequence for inducing the light phase modulation action to the light phase modulation means R1-2. An optical waveguide 22R for guiding the signal train;
Light from the optical output port P-C3-3 is connected to the optical input port P-L1-2 for inputting an optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means L1-2. An optical waveguide 22L for guiding the signal train;
Optical signal trains provided on the optical waveguide 22L or the optical waveguide 22R and simultaneously output from the optical output ports P-C3-3 and P-C3-4 are the optical input ports P-L1-2 and P-. An optical waveguide section DD-2 that generates an optical delay for adjusting the timing to reach R1-2 to be greater than the pulse width of the clock signal light CLK-1 and less than the pulse repetition period;
With
The optical signal string FF-1 is synchronized with the clock of the clock signal light CLK-1, is synchronized with the cycle of the data pattern, and has the same length as the data length of the data pattern. Signal sequence,
After the data pattern is maintained in the circuit, when the optical signal sequence FF-1 is input from the external optical input port P-FF-In, the input optical signal sequence FF-1 is used to The phase modulation means R1-2 and L1-2 are driven to cause a phase difference in the optical signal sequence output from the phase modulation means R1-1 and L1-1, and each pulse of the optical signal sequence is turned on. Alternatively, the optical signal train CLK-1-out-DMZ1 output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross A flip-flop having a data pattern obtained by inverting the data pattern of the optical signal sequence Data-1 is performed to circulate to the optical branching unit C-1.
Subsequent rounds are the previous rounds of the optical signal train CLK-1-out- output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross. Using the DMZ1, the phase modulation means R1-1 and L1-1 are driven to cause a phase difference in the clock signal light CLK-1 propagating through the two optical interference arms, and the clock By turning each pulse of the signal light CLK-1 on or off, the rotation output from either the light output port P-MZ-1-bar or the light output port P-MZ-1-cross The optical signal sequence CLK-1-out-DMZ1 is circulated to the optical branching unit C-1 as a data pattern obtained by inverting the data pattern of the optical signal sequence Data-1, and the data pattern The over emissions be configured to maintain in the circuit,
The optical branching unit C-1 and the optical branching unit C-3 are respectively
A first multimode interference waveguide section having two optical input ports and two optical output ports;
A second multimode interferometric waveguide section having two optical input ports and two optical output ports;
Two optical waveguides respectively connecting two output ports of the first multimode interference waveguide section and two optical input ports of the second multimode interference waveguide section;
A memory circuit comprising: an optical phase adjusting unit that adjusts a phase of light that is disposed in at least one of the two optical waveguides and that propagates through the waveguide.

The optical signal buffer memory circuit of the present invention is
Furthermore, an external optical input port P-ERS-In for inputting an optical signal string ERS-1 for erasing control for erasing the data pattern maintained in the circuit,
The optical input ports P-C2-1 and P-C2-2 and the optical output port P-C2-4 connected to the optical waveguide 18 are included, and the optical input ports P-C2-1 and P-C2-2 are included. An optical multiplexing unit C-2 for coupling the optical signal sequence input from the same optical output port P-C2-4 to the same,
An optical waveguide 16 for guiding an optical signal string from the external optical input port P-Data-In to the optical input port P-C2-1;
An optical waveguide 17 for guiding an optical signal string from the external optical input port P-ERS-In to the optical input port P-C2-2;
With
The optical signal string ERS-1 is synchronized with the clock of the clock signal light CLK-1, is synchronized with the cycle of the data pattern, and has the same length as the data length of the data pattern. Signal sequence,
After the same data pattern as the data pattern of the optical signal sequence Data-1 or an inverted data pattern is maintained in the circuit, the optical signal sequence ERS-1 is input from the external optical input port P-ERS-In. The optical signal train ERS-1 and the optical signal train CLK- output from one of the optical output port P-MZ-1-bar and the optical output port P-MZ-1-cross. 1-out-DMZ1 is used to drive the phase modulation means R1-1 and L1-1 so that all the phases of the clock signal light CLK-1 propagating in the two optical interference arms are π. Modulate,
When the optical signal sequence FF-1 is input from the external optical input port P-FF-In simultaneously with the input of the optical signal sequence ERS-1, the input optical signal sequence FF-1 is used. The phase modulation means R1-2 and L1-2 are driven to further π-modulate the phase of the optical signal sequence output from the phase modulation means R1-1 and L1-1, and the optical signal sequence is By outputting from either one of the optical output port P-MZ-1-bar and the optical output port P-MZ-1-cross, the optical output port P-MZ-1-bar or the optical output port P- It is the structure which returns to the initial state where there is no light output from either one of MZ-1-cross,
The optical multiplexing unit C-2
A first multimode interference waveguide section having two optical input ports and two optical output ports;
A second multimode interferometric waveguide section having two optical input ports and two optical output ports;
Two optical waveguides respectively connecting two output ports of the first multimode interference waveguide section and two optical input ports of the second multimode interference waveguide section;
An optical phase adjusting unit arranged in at least one of the two optical waveguides to adjust the phase of light propagating through the waveguide.

The optical signal buffer memory circuit of the present invention is
An external optical input port P-OCLK-In for inputting the clock signal light CLK-1 output from the clock signal light source, and an optical output port located on the bar side with respect to the external optical input port P-OCLK-In Two first optical interference arms having P-MZ-1-bar and an optical output port P-MZ-1-cross located on the cross side, on the optical waveguide of one of the first optical interference arms An optical phase modulation means L1-1 for modulating the phase of the optical signal train positioned and propagating in the optical interference arm, and the optical interference arm positioned on the optical waveguide of the other first optical interference arm Mach-Zehnder interference type optical intensity modulation means MZ-1 having optical phase modulation means R1-1 for modulating the phase of the optical signal train propagating therethrough and functioning as a Mach-Zehnder type interferometer ,
An optical waveguide 18 directly or indirectly connected to an external optical input port P-Data-In for inputting an optical signal sequence Data-1 having information to be stored, and guiding the optical signal sequence Data-1.
An optical input port P-C1-1 connected to the optical waveguide 18 to which an optical signal string Data-1 from the external optical input port P-Data-In is input, and the optical output port P-MZ-1-bar Or P-C1-2 to which an optical signal train from any one of the optical output ports P-MZ-1-cross is input, and optical output ports P-C1-3, P-C1-4, Optical branching unit C-1 for branching and outputting the optical signal train input from the optical input ports P-C1-2 and P-C1-1 to the optical output ports P-C1-3 and P-C1-4 When,
An optical waveguide 14 that guides an optical signal train from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross to the optical input port P-C1-2;
The light from the optical output port P-C1-4 connected to the optical input port P-R1-1 for inputting the optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means R1-1. An optical waveguide 15R for guiding the signal train;
Light from the optical output port P-C1-3 connected to the optical input port P-L1-1 for inputting the optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means L1-1. An optical waveguide 15L for guiding the signal train;
The optical signal trains provided on the optical waveguide 15L or the optical waveguide 15R and simultaneously output from the optical output ports P-C1-3 and P-C1-4 are the optical input ports P-L1-1 and P-. An optical waveguide section DD-1 that generates an optical delay for adjusting the timing of reaching R1-1 to be greater than or equal to the pulse width of the clock signal light CLK-1 and less than the pulse repetition period;
With
As the clock signal light CLK-1, RZ (Return to Zero) type signal light is inputted from the external light input port P-OCLK-In,
When the optical signal string Data-1 synchronized with the clock of the clock signal light CLK-1 is input from the external optical input port P-Data-In, first, the input optical signal string Data-1 is changed. The phase modulation means R1-1 and L1-1 are driven to cause a phase difference in the clock signal light CLK-1 propagating through the two first optical interference arms, and Light output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross by turning on or off each pulse of the clock signal light CLK-1 The signal train CLK-1-out-DMZ1 is circulated to the optical branching unit C-1 as the same data pattern as the data pattern of the optical signal train Data-1,
Subsequent rounds are the previous rounds of the optical signal train CLK-1-out- output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross. Using DMZ1, the phase modulation means R1-1 and L1-1 are driven to cause a phase difference in the clock signal light CLK-1 propagating through the two first optical interference arms. By turning on or off each pulse of the clock signal light CLK-1, the light is output from either the light output port P-MZ-1-bar or the light output port P-MZ-1-cross. The optical signal sequence CLK-1-out-DMZ1 of the circulation is circulated to the optical branching unit C-1 as the same data pattern as the data pattern of the optical signal sequence Data-1, and the data In the optical signal the buffer memory circuit to maintain a pattern in said circuit,
Furthermore,
On the optical waveguide of one of the first optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-1, located on the rear stage side of the optical phase modulation means L1-1 and in the optical interference arm. Optical phase modulation means L1-2 for modulating the phase of the optical signal train propagating through
On the optical waveguide of the other first optical interference arm of the Mach-Zehnder interference type optical intensity modulation means MZ-1, and located on the rear stage side of the optical phase modulation means R1-1, Optical phase modulation means R1-2 for modulating the phase of the optical signal train propagating through
An external optical input port P-FF-In for inputting an optical signal sequence FF-1 for flip-flop control of the data pattern maintained in the circuit;
An optical input port P-C3-2 and optical output ports P-C3-3, P-C3-4, and the optical signal train FF-1 input from the external optical input port P-FF-In An optical branching unit C-3 for inputting from the optical input port P-C3-2 and branching out to the optical output ports P-C3-3 and P-C3-4;
An optical waveguide 21 for guiding the optical signal string FF-1 from the external optical input port P-FF-In to the optical input port P-C3-2;
The light from the light output port P-C3-4 connected to the light input port P-R1-2 for inputting the light signal sequence for inducing the light phase modulation action to the light phase modulation means R1-2. An optical waveguide 22R for guiding the signal train;
Light from the optical output port P-C3-3 is connected to the optical input port P-L1-2 for inputting an optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means L1-2. An optical waveguide 22L for guiding the signal train;
Optical signal trains provided on the optical waveguide 22L or the optical waveguide 22R and simultaneously output from the optical output ports P-C3-3 and P-C3-4 are the optical input ports P-L1-2 and P-. An optical waveguide section DD-2 that generates an optical delay for adjusting the timing to reach R1-2 to be greater than the pulse width of the clock signal light CLK-1 and less than the pulse repetition period;
An optical input port P-MZ-2-In for inputting an optical signal string output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross; , Two optical output ports P-Data-Out located on the bar side with respect to the optical input port P-MZ-2-In and two optical output ports P-MON-Out located on the cross side An optical interference arm, an optical phase modulation means L-2 for modulating the phase of an optical signal train that is located on the optical waveguide of one of the second optical interference arms and propagates through the optical interference arm, and the other And an optical phase modulation means R-2 for modulating the phase of the optical signal train which is located on the optical waveguide of the second optical interference arm and propagates through the optical interference arm, and is a Mach-Zehnder type Functions as an interferometer And Tsu Ha-Zehnder interference type light intensity modulating means MZ-2,
An optical waveguide 30 that guides an optical signal train from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross to the optical input port P-MZ-2-In When,
An external optical input port P-Gate-In for inputting an optical signal string Gate-1 for optical signal output opening / closing control for outputting an optical signal string of the data pattern maintained in the circuit; ,
An optical input port P-C4-2 and optical output ports P-C4-3 and P-C4-4, and the optical signal string Gate-1 input from the external optical input port P-Gate-In An optical branching unit C-4 for inputting from the optical input port P-C4-2 and branching out to the optical output ports P-C4-3 and P-C4-4;
An optical waveguide 41 for guiding the optical signal string Gate-1 from the external optical input / output port P-Gate-In to the optical input port P-C4-2;
An optical signal train from the optical output port P-C4-3 connected to an optical input port P-L2 for inputting a signal optical train for inducing an optical phase modulation action to the optical phase modulation means L-2. An optical waveguide 42L for guiding
An optical signal train from the optical output port P-C4-4 connected to an optical input port PR2-R2 for inputting a signal optical train for inducing an optical phase modulation action to the optical phase modulation means R-2. An optical waveguide 42R for guiding
An optical signal train provided on the optical waveguide 42L or the optical waveguide 42R and simultaneously output from the optical output ports P-C4-3 and P-C4-4 is sent to the optical input ports P-L2 and P-R2. And an optical waveguide section DD-3 that generates an optical delay for adjusting the arrival timing to be equal to or greater than the pulse width of the clock signal light CLK-1 and less than the pulse repetition period;
With
The optical signal string FF-1 is synchronized with the clock of the clock signal light CLK-1, is synchronized with the cycle of the data pattern, and has the same length as the data length of the data pattern. Signal sequence,
After the data pattern is maintained in the circuit, when the optical signal sequence FF-1 is input from the external optical input port P-FF-In, the input optical signal sequence FF-1 is used to The phase modulation means R1-2 and L1-2 are driven to cause a phase difference in the optical signal sequence output from the phase modulation means R1-1 and L1-1, and each pulse of the optical signal sequence is turned on. Alternatively, by turning off the optical signal train CLK-1-out-DMZ1 output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross, A flip-flop that performs a data pattern obtained by inverting the data pattern of the optical signal sequence Data-1 is circulated to the optical branching unit C-1,
Subsequent rounds are the previous rounds of the optical signal train CLK-1-out- output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross. Using DMZ1, the phase modulation means R1-1 and L1-1 are driven to cause a phase difference in the clock signal light CLK-1 propagating through the two first optical interference arms. By turning on or off each pulse of the clock signal light CLK-1, the light is output from either the light output port P-MZ-1-bar or the light output port P-MZ-1-cross. The optical signal sequence CLK-1-out-DMZ1 is circulated to the optical branching unit C-1 as a data pattern obtained by inverting the data pattern of the optical signal sequence Data-1, and the data pattern is An optical signal sequence output from either one of the optical output port P-MZ-1-bar and the optical output port P-MZ-1-cross is maintained in the circuit, and the optical signal sequence Data− As the same data pattern as 1, after transitioning to the repeatedly output state,
The optical signal string Gate-1 is synchronized with the clock of the clock signal light CLK-1, is synchronized with the cycle of the data pattern, and has the same length as the data length of the data pattern. Signal sequence,
When the optical signal sequence Gate-1 is input from the external optical input port P-Gate-In, the optical phase modulation means R-2 and L-2 are connected using the input optical signal sequence Gate-1. An optical signal that is driven and propagated through the two second optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-2, which is input from the optical input port P-MZ-2-In By generating a phase difference in the column, the optical signal sequence input from the optical input port P-MZ-2-In is converted into the optical output port P-Data only during the data length of the optical signal sequence Gate-1. -Output from Out,
The optical branching unit C-1, the optical branching unit C-3, and the optical branching unit C-4 are respectively
A first multimode interference waveguide section having two optical input ports and two optical output ports;
A second multimode interferometric waveguide section having two optical input ports and two optical output ports;
Two optical waveguides respectively connecting two output ports of the first multimode interference waveguide section and two optical input ports of the second multimode interference waveguide section;
An optical phase adjusting unit arranged in at least one of the two optical waveguides to adjust the phase of light propagating through the waveguide.

The optical signal buffer memory circuit of the present invention is
Furthermore, an external optical input port P-ERS-In for inputting an optical signal string ERS-1 for erasing control for erasing the data pattern maintained in the circuit,
The optical input ports P-C2-1 and P-C2-2 and the optical output port P-C2-4 connected to the optical waveguide 18 are included, and the optical input ports P-C2-1 and P-C2-2 are included. An optical multiplexing unit C-2 for coupling the optical signal sequence input from the same optical output port P-C2-4 to the same,
An optical waveguide 16 for guiding an optical signal string from the external optical input port P-Data-In to the optical input port P-C2-1;
An optical waveguide 17 for guiding an optical signal string from the external optical input port P-ERS-In to the optical input port P-C2-2;
With
The optical signal string ERS-1 is synchronized with the clock of the clock signal light CLK-1, is synchronized with the cycle of the data pattern, and has the same length as the data length of the data pattern. Signal sequence,
After the same data pattern as the data pattern of the optical signal sequence Data-1 or an inverted data pattern is maintained in the circuit, the optical signal sequence ERS-1 is input from the external optical input port P-ERS-In. The optical signal train ERS-1 and the optical signal train CLK- output from one of the optical output port P-MZ-1-bar and the optical output port P-MZ-1-cross. The phase of the clock signal light CLK-1 propagating in the two first optical interference arms by driving the phase modulation means R1-1 and L1-1 using 1-out-DMZ1 Π-modulate all
When the optical signal sequence FF-1 is input from the external optical input port P-FF-In simultaneously with the input of the optical signal sequence ERS-1, the input optical signal sequence FF-1 is used. The phase modulation means R1-2 and L1-2 are driven to further π-modulate the phase of the optical signal sequence output from the phase modulation means R1-1 and L1-1, and the optical signal sequence is By outputting from either one of the optical output port P-MZ-1-bar and the optical output port P-MZ-1-cross, the optical output port P-MZ-1-bar or the optical output port P- It is the structure which returns to the initial state where there is no light output from either one of MZ-1-cross,
The optical multiplexing unit C-2 includes:
A first multimode interference waveguide section having two optical input ports and two optical output ports;
A second multimode interferometric waveguide section having two optical input ports and two optical output ports;
Two optical waveguides respectively connecting two output ports of the first multimode interference waveguide section and two optical input ports of the second multimode interference waveguide section;
An optical signal buffer memory circuit comprising: an optical phase adjusting unit that adjusts a phase of light propagating through the waveguide disposed in at least one of the two optical waveguides .

  According to the present invention, it is possible to give an optical delay of an arbitrary integer multiple to the optical signal length to be stored for output, and there is a problem in the optical buffer memory described in [First Prior Art]. In the optical buffer memory described in [Second Prior Art], it is possible to overcome the problem that “the optical circuit becomes larger as the pattern of the adjustable optical delay amount increases”. Was caused by optical signal waveform deterioration due to the influence of mixed noise such as ASE from the optical amplifier for loss compensation used in the optical buffer memory circuit and the influence of the dispersion effect accompanying the optical waveguide in the optical buffer memory circuit. In other words, it is possible to provide an infinite optical delay amount in principle.

  Furthermore, according to the present invention, the phase adjustment unit capable of adjusting the optical phase amount according to the amount of injected current on the waveguide of the optical coupling / branching unit (optical branching unit and optical multiplexing unit) of the optical signal buffer memory circuit. Therefore, even if there is an error in the demultiplexing ratio of the multimode interference type waveguide section, the demultiplexing ratio of the optical output is desired by injecting an appropriate amount of current into the phase adjustment section. The value can be

1 is a schematic diagram showing a first example of an optical signal buffer memory circuit according to the present invention. FIG. FIG. 3 is a schematic diagram showing a second example of the optical signal buffer memory circuit according to the present invention. It is a timing chart of various optical signal sequences. (A)-(d) is the schematic which shows the structural example of an optical-optical phase modulation circuit. (A)-(c) is a block diagram which shows the specific example of an optical branching part and an optical multiplexing part. It is the schematic which shows an example of the optical buffer circuit comprised from the optical delay waveguide array, optical switch, and optical coupler which were examined conventionally. It is the schematic which shows an example of the optical circulation type buffer circuit comprised from an optical waveguide loop, the optical amplifier for propagation compensation, and an optical switch.

DESCRIPTION OF EMBODIMENTS Hereinafter, an optical signal buffer memory circuit according to the present invention will be described in detail based on embodiments.
The first example of the optical signal buffer memory circuit shown in FIG. 1 and the second example of the optical signal buffer memory circuit shown in FIG. 2 have the same basic configuration. Therefore, the first example and the second example of the optical signal buffer memory circuit will be described together.

  First, the optical signal buffer memory circuit shown in FIGS. 1 and 2 will be described, and then a specific example of the optical multiplexing / demultiplexing unit will be described.

  FIGS. 1 and 2 are schematic views showing the optical signal buffer memory circuit of this embodiment, and FIG. 3 is a timing chart of various optical signal trains in the optical signal buffer memory circuit shown in FIGS. FIGS. 4A to 4D are schematic diagrams showing configuration examples of the optical-optical phase modulation circuit used in the optical signal buffer memory circuit shown in FIGS.

(Constitution)
In the optical signal buffer memory circuit of the present embodiment, P-OCLK-In is “a clock optical pulse output from a clock signal light source as shown by“ OC source ”in FIG. This is an external optical input port of the clock signal light CLK-1 which becomes a “constant RZ (Return to Zero) type clock signal light”.

  Further, P-Data-In is an optical signal sequence Data- that becomes an “optical signal sequence for data input for the purpose of storing in the optical signal buffer memory circuit” as indicated by “OD source” in FIG. 1 is an external optical input port.

  Further, P-FF-In indicates “a mark (1) of information of an optical signal train for data stored in the optical signal buffer memory circuit” as indicated by “FF cntl.” In FIG. This is an external optical input port of the optical signal sequence FF- 1 that becomes a so-called flip-flop control optical signal sequence that is input when performing a flip-flop operation that inverts all the spaces (0).

  Further, P-ERS-In is “an optical signal string for erasure control that is input when resetting the information stored in the optical signal buffer memory circuit” as indicated by “ERS cntl.” In FIG. Is an external optical input port of the optical signal train ERS-1.

  C-2 has optical input ports P-C2-1, P-C2-2, optical output ports P-C2-3, and P-C2-4. The external optical input port P-Data-In To the optical input port P-C2-1 through the optical waveguide 16 and the optical input port P-C2 from the external optical input port P-ERS-In through the optical waveguide 17 to the optical input port P-C2-1. -2 is output from the same optical output port P-C2-4, and one optical input port P-C1-1 of the subsequent 2 × 2 optical branching unit C-1 is output. This is a 2 × 1 optical multiplexing part for coupling to the optical waveguide 18 leading to

  In addition, if the optical signal sequences Data-1 and ERS-1 can be switched and input by an external device, for example, the external optical input port P-Data-In is optically transmitted without using the optical multiplexing unit C-2. The optical signal train Data-1 or the optical signal train ERS-1 may be directly input to the optical waveguide 18 from the external optical input port P-Data-In.

  MZ-1 is an optical circuit unit used as a Mach-Zehnder interference type optical intensity modulation means, and two first optical interference arms on the left and right sides (optical waveguides 11R, 12R, 13R and optical waveguides 11L, 12L, 13L). The optical waveguide 11R and the optical waveguide 11L are partially disposed close to each other to form a directional coupler, and the optical waveguide 13R and the optical waveguide 13L are also partially disposed close to each other. Thus, a directional coupler is configured.

  R1-1, R1-2, L1-1, and L1-2 are input from the external optical input port P-OCLK-In to the Mach-Zehnder interference type light intensity modulation means MZ-1, and are Mach-Zehnder interference type. Optical phase for modulating the phase of a clock optical signal sequence (first clock optical signal sequence and second clock optical signal sequence to be described later) propagating through the two left and right first optical interference arms of the optical intensity modulation means MZ-1. Modulation means. The optical phase modulation means R1-1, R1-2, L1-1, and L1-2 are arranged between two directional couplers. Specifically, the optical phase modulation means R1-1 is an optical waveguide 11R. Between the optical waveguide 12R, the optical phase modulation means R1-2 between the optical waveguide 12R and the optical waveguide 13R, and the optical phase modulation means L1-1 between the optical waveguide 11L and the optical waveguide 12L. The phase modulation means L1-2 is disposed between the optical waveguide 12L and the optical waveguide 13L. That is, the optical phase modulation means R1-2 is located on the rear stage side of the optical phase modulation means R1-1, and the optical phase modulation means L1-2 is located on the rear stage side of the optical phase modulation means L1-1.

  Here, the first clock optical signal sequence is an optical signal sequence obtained by branching the clock signal light CLK-1 with a directional coupler, and the second clock optical signal sequence is in phase with the first clock optical signal sequence. It is an optical signal train after being subjected to optical phase modulation by the modulation means R1-1 and L1-1.

  P-MZ-1-cross is an optical output port for outputting an optical signal string from the cross side with respect to the external optical input port P-OCLK-In of the Mach-Zehnder interference type optical intensity modulation means MZ-1.

  Further, P-MZ-1-bar is the Mach-Zehnder interference light intensity modulation means MZ-1 from the bar side to the external optical input port P-OCLK-In of the Mach-Zehnder interference light intensity modulation means MZ-1. This is an optical output port that outputs an optical signal train CLK-1-out-DMZ1 that becomes the light intensity modulated light.

  C-1 has optical input ports P-C1-1, P-C1-2, optical output ports P-C1-3, P-C1-4, and the optical output of the optical multiplexing unit C-2. The optical signal train from the port P-C2-4 is input from the optical input port P-C1-1 and branched through the optical waveguide 18, and is split into the optical output ports P-C1-3 and P-C1-4. The optical signal train from the optical output port P-MZ-1-bar of the Mach-Zehnder interference type optical intensity modulation means MZ-1 is output via the optical waveguide 14 to the optical input port P- This is an optical branching unit for inputting and branching from C1-2 to output from optical output ports P-C1-3 and P-C1-4.

  Further, P-R1-1 and P-L1-1 convert the optical signal sequence output from the optical output ports P-C1-3 and P-C1-4 of the optical branching unit C-1 to the optical waveguide 15R, An optical input port for inputting to the optical phase modulation means R1-1 and L1-1 in the two first optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-1 via 15L .

  C-3 has optical input ports P-C3-1, P-C3-2, optical output ports P-C3-3, and P-C3-4. The external optical input port P-FF-In From the optical output port P-C3-3 and P-C3-4, an optical branching unit for branching the input optical signal train via the optical waveguide 21 is provided.

  Further, P-R1-2 and P-L1-2 respectively convert the optical signal sequence output from the optical output ports P-C3-3 and P-C3-4 of the optical branching unit C-3 into the optical waveguide 22R, This is an optical input port for inputting to the optical phase modulation means R1-2 and L1-2 in the two first optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-1 via 22L. .

  Further, DD-1 is branched by the optical branching unit C-1, and optical phase modulation means R1 is added to two optical signal trains output from the optical output ports P-C1-3 and P-C1-4, respectively. -1 and L1-1 are optical propagation delay difference giving units for giving the optical propagation delay difference so as to be "more than the pulse width of the clock optical signal CLK-1 and less than the pulse repetition period" Here, the optical waveguide portion having the optical path length that causes the above-described optical propagation delay difference is arranged in the optical waveguide 15L.

  Further, DD-2 is optical phase modulation means R1- in the two optical signal trains branched from the optical branching section C-3 and output from the optical output ports P-C3-3 and P-C3-4. 2, an optical propagation delay difference providing unit for applying an optical propagation delay difference until reaching L1-2 to be “more than a pulse width of the clock optical signal CLK-1 and less than a pulse repetition period”; Here, an optical waveguide portion having an optical path length that causes the above-described optical propagation delay difference is arranged in the optical waveguide 22L.

  MZ-2 is an optical circuit unit used as Mach-Zehnder interference type light intensity modulation means, and has two right and left second optical interference arms (optical waveguides 31R and 32R and optical waveguides 31L and 32L). In the optical waveguide 31R and the optical waveguide 31L, a part is arranged close to each other to form a directional coupler, and in the optical waveguide 32R and the optical waveguide 32L, part is arranged close to each other, It constitutes a coupler.

  P-MZ-2-In transmits an optical signal string output from the optical output port P-MZ-1-cross of the Mach-Zehnder interference type optical intensity modulation means MZ-1 through the optical waveguide 30. These are optical input ports for inputting to the Mach-Zehnder interference type optical intensity modulation means MZ-2.

  P-Data-Out is an optical output port that outputs an optical signal train from the bar side to the optical input port P-MZ-2-In of the Mach-Zehnder interference type optical intensity modulation means MZ-2. P-MON-Out is an optical output port that outputs an optical signal train from the cross side.

  R-2 and L-2 are input from the optical input port P-MZ-2-In to the Mach-Zehnder interference type light intensity modulation means MZ-2, and are Mach-Zehnder interference type light intensity modulation means MZ-2. The optical phase modulation means modulates the phase of the optical signal train propagating through the two right and left second optical interference arms. The optical phase modulation means R-2 and L-2 are arranged between two directional couplers, and the optical phase modulation means R-2 is arranged between the optical waveguide 31R and the optical waveguide 32R. L-2 is disposed between the optical waveguide 31L and the optical waveguide 32L.

  Further, P-Gate-In is connected to the optical output port by performing a flip-flop operation after being stored in the optical signal buffer memory circuit, as shown in “Shutter cntl.” Of FIG. An optical signal sequence output from the P-MZ-1-cross, that is, an optical signal sequence having the same data pattern as that of the optical signal sequence Ddata-1 input for the purpose of storing in the optical signal buffer memory circuit is used as the optical signal sequence. This is an external optical input port of the optical signal sequence Gate-1 which becomes an optical signal sequence for optical shutter opening / closing control "that is input when the output port P-Data-Out is guided and output.

  C-4 has optical input ports P-C4-1, P-C4-2, optical output ports P-C4-3, and P-C4-4. The external optical input port P-Gate-In From the optical output port P-C4-3 and P-C4-4, an optical branching unit for branching the input optical signal train through the optical waveguide 41 is provided.

  Further, P-R2 and P-L2 are optical signal strings output from the optical output ports P-C4-3 and P-C4-4 of the optical branching unit C-4 via the optical waveguides 42R and 42L. These are optical input ports for inputting to the optical phase modulation means R-2 and L-2 in the two second optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-2.

  Further, DD-3 is branched by the optical branching section C-4, and optical phase modulation means R is respectively added to two optical signal trains output from the optical output ports P-C4-3 and P-C4-4. -2 and L-2 are optical propagation delay difference providing units for providing the optical propagation delay difference to be “more than the pulse width of the clock optical signal CLK-1 and less than the pulse repetition period”. Here, the optical waveguide portion having the optical path length causing the above-mentioned optical propagation delay difference is arranged in the optical waveguide 42R.

  The optical signal sequences FF-1, ERS-1, and Gate-1 that are optical signal sequences for control use, for example, one or individual generators that generate optical pulse sequences that are optical signal sequences. The external optical input ports P-FF-In, P-ERS-In, and P are synchronized with the clock signal light CLK-1 and the optical signal train Data-1 (or the optical signal train CLK-1-out-DMZ1). -Input only from Gate-In.

  Here, in the optical circuit of the present embodiment, the waveguide portion is constituted by a low-loss semiconductor waveguide, and the optical phase modulation means R1-1, R1-2, L1-1, L1-2, R-2, As L-2, a semiconductor optical amplifier (SOA) is used, or an optical semiconductor circuit including optical phase modulation means shown in FIGS. 4A to 4D described later is used, or a quantum dot SOA ( QD-SOA) is used, or a semiconductor EA (Electro-Absorption) modulator is used by constant voltage drive, and the whole is integrated with an optical semiconductor.

  Alternatively, the optical waveguide portion is composed of PLC (quartz-based planar lightwave circuit), and the SOA is used as the optical phase modulation means R1-1, R1-2, L1-1, L1-2, R-2, L-2. Or a PLC-optical semiconductor hybrid circuit comprising optical phase modulation means shown in FIGS. 4A to 4D to be described later, or a QD-SOA, or a semiconductor EA modulator As a configuration using a constant voltage drive, the whole is manufactured by a hybrid of PLC and an optical semiconductor (see Non-Patent Document 4).

  Alternatively, a photonic crystal waveguide is used for the optical waveguide portion, and a quantum dot group is used as a core layer in the optical phase modulation means R1-1, R1-2, L1-1, L1-2, R-2, and L-2. The entire structure is integrated and manufactured (see Non-Patent Document 5).

  An example of the configuration of the optical phase modulation means R1-1, R1-2, L1-1, L1-2, R-2, L-2 used in the optical circuit of this embodiment is shown in FIGS. Will be described with reference to FIG. 4 (a) to 4 (d) show the optical circuit configuration of the optical-optical phase modulation means to be the optical phase modulation means R1-1, R1-2, L1-1, L1-2, R-2, L-2. It is the figure which showed the example. Here, for convenience, the two input optical signal trains are referred to as “light phase modulated signal light” and “optical phase modulation control signal light”.

  4A to 4D, a1, a2, a3, and a4 are optical input / output ports of the entire optical circuit of the optical-optical phase modulation means, and b1 and b2 are multimode interference couplers (first, A5, a6 are optical input / output ports of the multimode interference coupler b1, a7, a8 are optical input / output ports of the multimode interference coupler b2, and e1, e2 , E3, e4 are optical input / output waveguides of the entire optical circuit of the optical-optical phase modulation means, and e5, e7, e6, e8 are optical waveguides constituting two right and left optical interference arms. 4A to 4D, the case where signal light is input from the left side and output from the right side in the figure will be described. However, left and right may be reversed, and one optical interference arm and the other light may be used. The input and output of the signal light to the interference arm may be opposite to each other. Therefore, a1 to a8 are called “optical input / output ports”.

  In the multimode interference coupler b1, when “light phase modulated signal light” and “light phase modulation control signal light” are input from the two optical input / output ports a1 and a2, respectively, “inputted from the optical input / output ports a1 and a2” The “light phase modulation signal light” and the “light phase modulation control signal light” are branched, and one of the branched “light phase modulation signal light” and one of the “light phase modulation control signal light” are combined. , Output from the optical input / output port a5 (this is referred to as the first signal light for the sake of convenience), and the other of the “light phase modulation signal light” branched and the other of the “light phase modulation control signal light” Are output from the optical input / output port a6 (this is referred to as second signal light for convenience).

  Similarly, in the multimode interference coupler b2, when the “first signal light” and the “second signal light” are input from the two optical input / output ports a7 and a8, respectively, they are input from the optical input / output ports a7 and a8. Each of the “first signal light” and the “second signal light” is branched, and one of the branched “first signal light” and one of the “second signal light” is combined to receive light. The other of the “first signal light” branched from the output port a3 and the other of the “second signal light” are combined and output from the light input / output port a4.

  In addition, c1 and c2 are optical phase modulation units having an optical waveguide structure having a property that the refractive index changes according to the light intensity of the “optical phase modulation control signal light”. Either an optical semiconductor amplifier (SOA), an optical waveguide structure including a quantum dot layer, or a semiconductor EA modulator in a constant voltage drive state. The optical phase modulator c1 is disposed between the optical waveguides e5 and e7, and the optical phase modulator c2 is disposed between the optical waveguides e6 and e8.

  As described above, as the optical-optical phase modulation means, the two multi-mode interference couplers (MMI) b1 and b2 perform the function of adding the optical phase modulation to the optical phase modulation units c1 and c2 (for example, an optical semiconductor amplifier ( A Mach-Zehnder interference circuit connected by an optical interference arm including SOA)) is used.

  Then, as shown in FIG. 4 (a), the lengths of the two optical interference arms are strictly adjusted at the time of manufacture, or as shown in FIGS. 4 (b) to (d), the injection current amount is adjusted. An additional phase adjuster d1, d2 that can adjust the phase of the optical signal in accordance with this is provided in one or both of the optical interference arms, and the phase adjuster d1, d2 is used to adjust the optical path length during use. Use these means.

  With such a configuration, for example, when “optical phase modulation signal light” is input from the optical input / output port a1 and “optical phase modulation control signal light” is input from the optical input / output port a2, the optical input / output port The “light phase modulated signal light” from the port a1 is selectively output to either the light input / output port a3 or a4, and the “light phase modulation control signal light” from the light input / output port a2 is Are output to an optical input / output port a4 or a3 serving as an optical input / output port different from the optical input / output port for selectively outputting the “light-receiving phase modulated signal light”. As a result, the “optical phase modulation control signal light” is input to the optical-optical phase modulation means, and the optical phase modulation is applied to the “photo phase modulation signal light”. At the same time, either the optical input / output port a3 or a4 Only “light phase modulated signal light” can be selectively output from one side (see Non-Patent Documents 2 and 3).

  For example, in the optical phase modulation means R1-1 in FIGS. 1 and 2, the “optical phase modulation control signal light” is the optical signal sequence Data-1 or the optical signal sequence CLK-1-out-DMZ1, The “optical phase modulated signal light” is input from the optical input port PR-R1-1 corresponding to the output port a1, and is the first clock optical signal train (clock signal light CLK-1). The first clock light that is input from the input port of the connected optical phase modulation means R1-1 and that has been subjected to optical phase modulation from the output port of the optical phase modulation means R1-1 to which the optical waveguide 12R is connected. Only the signal train, that is, the second clock optical signal is selectively output. The optical phase modulation means L1-1 in FIGS. 1 and 2 also functions in the same manner.

  Also, in the optical phase modulation means R1-2 in FIGS. 1 and 2, the “optical phase modulation control signal light” is the optical signal string FF-1, and the optical input port P− corresponding to the optical input / output port a1. The “light-phase-modulated signal light” input from R1-2 is a first clock optical signal sequence that is phase-modulated by the optical phase modulation means R1-1, that is, a second clock optical signal sequence, The optical phase modulation means R1-2 connected to the waveguide 12R is input from the input port, and the second optical phase modulation is applied from the output port of the optical phase modulation means R1-2 connected to the optical waveguide 13R. Only the clock optical signal train is selectively output. The optical phase modulation means L1-2 in FIGS. 1 and 2 also functions in the same manner.

  Next, operations in the optical signal buffer memory circuit of this embodiment, specifically, data holding (buffering), flip-flop, output, and stored data erasing will be described with reference to FIG. 1, FIG. 2, and FIG. To do.

(Operation-Data retention)
In the standard Mach-Zehnder interferometric light intensity modulation means, the state where no phase difference occurs when light propagates through the two optical interference arms constituting the interferometer is the state where modulation driving is not performed. Yes, at this time, 100% of the optical signal is output from the cross side with respect to the input side. On the other hand, when the phase difference is π, an optical signal is output 100% from the bar side.

  Therefore, when the clock signal light CLK-1 is input from the external optical input port P-OCLK-In to the optical signal buffer memory circuit shown in FIGS. 1 and 2, the clock optical signal CLK-1 is 100% optical output. Output from the port P-MZ-1-cross, and no optical output is obtained from the optical output port P-MZ-1-bar (empty state in which the optical signal buffer memory does not hold any information: initial State).

  At this time, as indicated by “OD source” in FIG. 3, the clock signal light CLK-1 continuously input from the external optical input port P-OCLK-In of the Mach-Zehnder interference type optical intensity modulation means MZ-1 The optical signal sequence Data-1 that is synchronized with the input signal is input from the external optical input port P-Data-In, and drives the optical phase modulation means R1-1 and L1-1. The phase of the first clock optical signal train (clock signal light CLK-1) propagating through the optical interference arm is π-modulated to turn on or off each pulse of the first clock optical signal train.

  Then, π phase modulation is applied only to the clock pulse of the first clock optical signal sequence corresponding to the pulse at the position of Mark (1) of the optical signal sequence Data-1, and the space of the optical signal sequence Data-1 is added. Since the phase modulation is not applied to the clock pulse of the first clock optical signal sequence corresponding to the pulse at position (0), the optical output port of MZ-1 has the same data pattern as the optical signal sequence Data-1. It is output from P-MZ-1-bar. In FIG. 3, an 8-bit optical signal string “10101010” is input as an example of the optical signal string Data-1.

  The optical signal sequence CLK-1-out-DMZ1 output from P-MZ-1-bar, which has the same data pattern as the optical signal sequence Data-1, is transmitted via the optical branching unit C-1. In order to induce optical phase modulation by being input to the phase modulation means R1-1 and L1-1, the first optical interference on the left and right sides of the Mach-Zehnder interference type light intensity modulation means MZ-1 is also performed in the next round. The first clock optical signal sequence propagating in the arm is subjected to the same optical phase modulation as described above by the optical signal sequence CLK-1-out-DMZ1 having the same data pattern as the large optical signal sequence Data-1. As a result, the output from the optical output port P-MZ-1-bar of the MZ-1 with the same data pattern as that of the large optical signal sequence Data-1 is repeated, and as a result, “Buffering Stat” of FIG. As shown in FIG. 3 (see the optical signal pulse train for three cycles of N = 1 to 3 in FIG. 3), the same data pattern as that of the optical signal sequence Data-1 is applied to the optical signal buffer memory circuit in a series of driving. It will be held as a state.

  At this time, as in the optical buffer memory described in [Second Prior Art], “the signal data pattern is held by continuing to propagate the large optical pulse train through the optical waveguide loop while repeating optical amplification. Unlike the case, in the present embodiment, the optical signal sequence Data-1 or the optical signal sequence CLK-1-out-DMZ1 that becomes the “optical phase modulation control signal light” is used to obtain “optical phase modulation signal light”. A new optical signal sequence having the same data pattern as that of the optical signal sequence Data-1 is copied (copied) by turning on or off each pulse of the clock signal light CLK-1, and therefore, an optical signal buffer memory. It is possible to eliminate the influence of mixed noise such as ASE from the optical amplifier for loss compensation used in the circuit and the influence of the dispersion effect due to the optical waveguide in the optical signal buffer memory circuit. So that the noteworthy property that it is no longer available for grant optical delay limits due to waveform degradation occurs is realized.

(Operation-flip-flop)
Further, in the state where the same data pattern as that of the optical signal string Data-1 is held in the optical signal buffer memory circuit as a series of driving states as described above, the “FF cntl.” Of FIG. As described above, the clock signal light CLK-1 continuously inputted from the external optical input port P-OCLK-In of the Mach-Zehnder interference type optical intensity modulation means MZ-1 is synchronized, and a series of driving states have already been achieved. The period of the optical signal sequence Data-1 and the same data pattern as that of the optical signal sequence Data-1 held as the data pattern is also synchronized. -In is input and drives the optical phase modulation means R1-2 and L1-2 to propagate in the left and right first optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-1. The phase of the second clock optical signal train (the first clock optical signal train subjected to phase modulation) is π-modulated to turn on or off each pulse of the second clock optical signal train.

  Then, due to the effect of a series of driving states that have already been held, the Mach-Zehnder interference type light intensity modulating means MZ is combined with the optical phase modulation given by π in the optical phase modulating means R1-1 and L1-1. The phase modulation of the first clock optical signal sequence propagating through the left and right first optical interference arms of −1 is the optical signal sequence Data-1 (or the optical signal sequence CLK-1-out-DMZ1). An optical signal sequence in which phase modulation of 2π is applied to the clock pulse of the first clock optical signal sequence corresponding to the pulse at the position of Mark (1) and phase modulation is not applied in the previous round. The clock pulse of the first clock optical signal sequence corresponding to the pulse at the position (0) of Data-1 (or optical signal sequence CLK-1-out-DMZ1) has a phase of π. So that the tone is given.

  As a result, the clock pulse train subjected to the optical phase modulation becomes a data pattern inverted from the optical signal train Data-1, and the optical output port P-MZ-1 of the Mach-Zehnder interference type optical intensity modulation means MZ-1 is obtained. The clock pulse train output from -bar and simultaneously subjected to these optical phase modulations has the same data pattern as that of the optical signal sequence Data-1, and the optical output port of the Mach-Zehnder interference type optical intensity modulation means MZ-1 P-MZ-1-cross is output, and so-called flip-flop operation is realized. As a result, as shown in “Buffering State” in FIG. 3 (refer to the optical signal pulse train for two cycles of N = 4 to 5 in FIG. 3), the data pattern inverted from the optical signal sequence Data-1 (“ 01010101 "8-bit optical signal string) is held in the optical signal buffer memory circuit as a series of driving states.

(Operation-Output)
Further, as described above, the same data pattern as that of the optical signal sequence Data-1 is repeatedly output from the optical output port P-MZ-1-cross of the optical signal buffer memory circuit, and the optical input port P-MZ-2- In a state where the signal is input from In to the Mach-Zehnder interference type light intensity modulation means MZ-2, as shown in “Shutter cntl.” In FIG. The inverted data pattern of the optical signal sequence Data-1 (or the data signal-1 that is synchronized with the clock signal light CLK-1 continuously input from the optical input port P-OCLK-In and already held as a series of driving states (or The period of the optical signal sequence (the same data pattern as that of the optical signal sequence Data-1) that is repeatedly input to the optical input port P-MZ-2-In is also synchronized. Then, an optical signal sequence Gate-1 having the same length as the data length of this data pattern is input from the external optical input port P-Gate-In, and drives the optical phase modulation means R-2 and L-2. The phase of the optical signal sequence (the optical signal sequence having the same data pattern as that of the optical signal sequence Data-1) propagating through the left and right second optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-2 π modulated.

  Then, in the period when the optical phase modulation is performed, as shown in the output of FIG. 3 only during the time window in which the optical signal sequence Gate-1 is input, that is, during the data length of the optical signal sequence Gate-1. An optical signal sequence having the same data pattern as that of the optical signal sequence Data-1 input from the optical input port P-MZ-2-In of the Mach-Zehnder interference type optical intensity modulation means MZ-2 is used as the optical output port P-Data-. It can be output from Out.

(Operation-Reset)
Further, in the state where the same data pattern or inverted data pattern as that of the optical signal sequence Data-1 is held in the optical signal buffer memory circuit as a series of driving states as described above, “ERS cntl.” In FIG. As shown, the clock signal light CLK-1 continuously inputted from the external optical input port P-OCLK-In of the Mach-Zehnder interference type optical intensity modulation means MZ-1 is synchronized, and a series of driving has already been performed. The period of the same data pattern or inverted data pattern as the optical signal sequence Data-1 held as the state is also synchronized, and the optical signal sequence ERS-1 having the same length as the data length of this data pattern is external light. Input from the input port P-ERS-In, already output from the optical output port P-MZ-1-bar, and optical phase modulation via the optical branching unit C-1 Along with the optical signal train CLK-1-out-DMZ1 input to the means R1-1 and L1-1, the optical phase modulation means R1-1 and L1-1 are driven, and the optical phase modulation means R1-1, In the SOA constituting L1-1, by utilizing the saturation effect on the control light pulse power of the phase modulation effect of the SOA due to the gain saturation effect, left and right of the Mach-Zehnder interference type light intensity modulation means MZ-1 All the phases of the first clock optical signal train propagating in the first optical interference arm are π-modulated.

  At the same time, as shown in “FF cntl.” In FIG. 3, the clock continues to be input from the external optical input port P-OCLK-In of the Mach-Zehnder interference type optical intensity modulation means MZ-1. The same data pattern or inverted data pattern as the optical signal string Data-1 that is synchronized with the signal light CLK-1 and is already held as a series of driving states (repeatedly input to the optical input port P-MZ-2-In The optical signal sequence FF-1 having the same length as the data length of the data pattern is also synchronized with the period of the optical signal sequence Data-1 and the same data pattern). Is input from −In, drives the optical phase modulation means R1-2 and L1-2, and propagates in the left and right first optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-1. A second optical clock signal train of the phase is π causing modulation.

  In general, the phase of the first clock optical signal sequence propagating in the left and right first optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-1 is modulated by 2π, and all clock pulses are optically output. By outputting from the port P-MZ-1-cross, no optical output can be obtained from the optical output port P-MZ-1-bar described above (the optical signal buffer memory holds no information) (Empty state: initial state).

  Here, although the optical waveguide 14 is connected to the optical output port P-MZ-1-bar and the optical signal train CLK-1-out-DMZ1 is circulated to the optical branching section C-1, the optical output is The optical waveguide 14 may be connected to the port P-MZ-1-cross so that the optical signal train CLK-1-out-DMZ1 circulates to the optical branching unit C-1. In that case, the optical propagation delay difference providing unit DD-1 is provided on the optical waveguide 15R, the optical propagation delay difference providing unit DD-2 is provided on the optical waveguide 22R, and the optical output port P-MZ. The optical waveguide 30 is connected to -1-bar.

  Similarly, here, an optical signal sequence having the same data pattern as the optical signal sequence Data-1 is output from the optical output port P-Data-Out, but the optical signal sequence is output from the optical output port P-MON-Out. An optical signal string having the same data pattern as that of Data-1 may be output. In that case, the optical propagation delay difference providing part DD-3 is provided on the optical waveguide 42L.

(Specific example of optical coupling part)
In the first example of the optical signal buffer memory circuit shown in FIG. 1, a set of optical phase modulation means L1-1 and optical phase modulation means R1-1 of the Mach-Zehnder interference type optical intensity modulation means MZ-1, the optical phase The intensity ratio of the optical phase modulation control signal light (control light pulse) input to the set of the modulation means L1-2 and the optical phase modulation means R1-2 is the optical phase modulation means L1 input with a delay of the control light pulse. −1, L1-2 side is weaker in accordance with the amount of optical delay than the optical phase modulation means R1-1, R1-2 side to which the control light pulse is input first. Need to be adjusted. If this balance is lost, a desired light intensity modulation operation cannot be realized in the Mach-Zehnder interference type light intensity modulation means MZ-1.

  Similarly, in the second example of the optical signal buffer memory circuit shown in FIG. 2, the optical phase modulation means L1-1 and the optical phase modulation means R1 of the Mach-Zehnder interference type optical intensity modulation means MZ-1, MZ-2. −1, optical phase modulation means L1-2 and optical phase modulation means R1-2, and optical phase modulation control input to the optical phase modulation means L-2 and optical phase modulation means R-2. The ratio of the intensity of the signal light ((control light pulse) is such that the control light pulse is earlier on the side of the optical phase modulation means L1-1, L1-2, R-2 to which the control light pulse is input with a delay. It is necessary to adjust the optical phase modulation means R1-1, R1-2, and L-2 to be weaker in accordance with the amount of optical delay when the balance is lost. Desired light intensity modulation operation in the Zender interference type light intensity modulation means MZ-1 and MZ-2 Can not be realized.

When an optical signal buffer memory circuit is realized as a planar substrate type integrated optical circuit, the simplest configuration as an optical coupling / branching unit in the optical circuit is one optical input port, two optical output ports, and one multimode. There is a configuration in which a so-called MMI type optical demultiplexing circuit including an interference type waveguide unit is applied.
In the case of such an MMI type optical demultiplexing circuit, it is difficult to correct an error from the design branching ratio caused by a manufacturing error or the like after the optical circuit is created. There is a problem that such an error of the optical branching ratio from the design branching ratio causes the light intensity modulation characteristic in the Mach-Zehnder interference type light intensity modulation means in the optical signal buffer memory circuit to deviate from the design characteristic.

Therefore, the optical branching units C-1, C-3 and the optical multiplexing unit C-2 used in the first example of the optical signal buffer memory circuit, or the second example of the optical signal buffer memory circuit are used. Various specific examples of the optical branching units C-1, C-3, C-4 and the optical multiplexing unit C-2 are configured as follows to solve the above problems.
In the following description, specific examples of the optical branching units C-1, C-3, C-4 and the optical multiplexing unit C-2 will be described as optical multiplexing / branching units 100, 110, 120. That is, each of the optical multiplexing and branching units 100, 110, and 120 can be applied to any of the optical branching units C-1, C-3, C-4, and the optical multiplexing unit C-2.

<First specific example of optical coupling part>
The optical coupling / branching unit 100, which is a first specific example of the optical coupling / branching unit, will be described with reference to FIG. The optical coupling / branching unit 100 is an optical coupling / branching unit constituting the Mach-Zehnder interferometer as a whole.
One multi-mode interference waveguide section b1 of the optical coupling / branching section 100 has optical input ports a1 and a2 and optical output ports a5 and a6, and 50 light input from the optical input ports a1 and a2 is received. It has a function of demultiplexing at a rate of% optical power and outputting from two optical output ports a5 and a6.
The other multimode interference waveguide section b2 of the optical coupling / branching section 100 has optical input ports a7 and a8 and optical output ports a3 and a4, and 50 light input from the optical input ports a7 and a8 is received. It has the function of demultiplexing at a rate of% optical power and outputting from two optical output ports a3 and a4.

The optical output port a5 and the optical input port a7 are connected by an optical waveguide wg1, and the optical output port a6 and the optical input port a8 are connected by an optical waveguide wg2.
On the optical waveguide wg1, an optical phase adjusting unit d1 capable of adjusting the phase of light propagating through the optical waveguide wg1 is disposed. As the optical phase adjustment unit d1, for example, a type capable of adjusting the optical phase amount according to the injection current amount can be adopted.
On the optical waveguide wg2, an optical phase adjusting unit d2 capable of adjusting the phase of light propagating through the optical waveguide wg2 is disposed. As the optical phase adjustment unit d2, for example, a type capable of adjusting the optical phase amount according to the injection current amount can be adopted.

Optical branching units C-1, C-3 and optical multiplexing unit C-2 used in the first example of the optical signal buffer memory circuit, or optical branching used in the second example of the optical signal buffer memory circuit If the optical coupling / branching unit 100 is employed as the units C-1, C-3, C-4 and the optical multiplexing unit C-2, the following effects can be obtained.

That is, the branching ratio of the optical output power of the light propagating to the optical output ports a3 and a4 of the optical coupling / branching unit 100 by adjusting the amount of current injected into both or one of the optical phase adjustment units d1 and d2. Can be adjusted.
For this reason, even if the demultiplexing ratio of the multimode interference waveguide sections b1 and b2 on the optical coupling / branching section 100 becomes different from the design due to a manufacturing error or the like, the first of the optical signal buffer memory circuit. The desired light intensity in the Mach-Zehnder interference type light intensity modulation means MZ-1 in the first example and the Mach-Zehnder interference type light intensity modulation means MZ-1, MZ-2 in the second example of the optical signal buffer memory circuit. Modulation characteristics can be realized.

<Second specific example of optical coupling / branching unit>
An optical coupling / branching unit 110, which is a second specific example of the optical coupling / branching unit, will be described with reference to FIG. The optical coupling / branching unit 110 shown in FIG. 5B is an optical coupling / branching unit constituting the Mach-Zehnder interferometer as a whole, and the basic configuration is the same as that of the optical coupling / branching unit 100 shown in FIG. Therefore, the same parts as those of the optical combining / branching unit 100 are denoted by the same reference numerals, and redundant description is omitted, and only different parts are described.

  In the optical coupling / branching unit 110, the optical phase adjustment unit d1 is disposed only on the optical waveguide wg1 of the two optical waveguides wg1 and wg2, and the optical phase adjustment unit is not disposed on the optical waveguide wg2. As the optical phase adjustment unit d1, for example, a type capable of adjusting the optical phase amount according to the injection current amount can be adopted.

Also in the optical coupling / branching unit 110, which is a second specific example of the optical coupling / branching unit, the light propagating to the optical output ports a3, a4 of the optical coupling / branching unit 110 by adjusting the amount of current injected into the optical phase adjustment unit d1. The optical output power branching ratio can be adjusted.
For this reason, even if the demultiplexing ratio of the multimode interference waveguide sections b1 and b2 on the optical coupling / branching section 110 becomes different from the design due to a manufacturing error or the like, the first of the optical signal buffer memory circuit The desired light intensity in the Mach-Zehnder interference type light intensity modulation means MZ-1 in the first example and the Mach-Zehnder interference type light intensity modulation means MZ-1, MZ-2 in the second example of the optical signal buffer memory circuit. Modulation characteristics can be realized.

<Third specific example of optical coupling part>
An optical coupling / branching unit 120, which is a third specific example of the optical coupling / branching unit, will be described with reference to FIG. The optical coupling / branching unit 120 shown in FIG. 5C is an optical coupling / branching unit constituting a Mach-Zehnder interferometer as a whole, and the basic configuration is the same as that of the optical coupling / branching unit 100 shown in FIG. Therefore, the same parts as those of the optical combining / branching unit 100 are denoted by the same reference numerals, and redundant description is omitted, and only different parts are described.

  In the optical coupling / branching unit 120, the optical phase adjustment unit d2 is arranged only on the optical waveguide wg2 of the two optical waveguides wg1 and wg2, and the optical phase adjustment unit is not arranged on the optical waveguide wg1. As the optical phase adjustment unit d2, for example, a type capable of adjusting the optical phase amount according to the injection current amount can be adopted.

Also in the optical coupling / branching unit 120, which is the third specific example of the optical coupling / branching unit, the light propagating to the optical output ports a3, a4 of the optical coupling / branching unit 120 by adjusting the amount of current injected into the optical phase adjustment unit d2. The optical output power branching ratio can be adjusted.
For this reason, even if the demultiplexing ratio of the multimode interference waveguide sections b1 and b2 on the optical coupling / branching section 120 becomes different from the design due to a manufacturing error or the like, the first of the optical signal buffer memory circuit The desired light intensity in the Mach-Zehnder interference type light intensity modulation means MZ-1 in the first example and the Mach-Zehnder interference type light intensity modulation means MZ-1, MZ-2 in the second example of the optical signal buffer memory circuit. Modulation characteristics can be realized.

  The present invention is applicable to optical communication, optical processing, and an optical signal buffer memory circuit in an optical computer.

MZ-1: Mach-Zehnder interference type optical intensity modulation means P-OCLK-In: external optical input port for clock signal light input P-MZ-1-bar: light positioned on the bar side with respect to P-OCLK-In Output port P-MZ-1-cross: optical output port R1-1 located on the cross side with respect to P-OCLK-In: optical phase modulation means P-R1-1: control to optical phase modulation means R1-1 Optical light input port L1-1: Optical phase modulation means P-L1-1: Control light optical input port R1-2 to optical phase modulation means L1-1: Optical phase modulation means PR1-2: Optical phase Light input port L1-2 for control light to modulation means R1-2: Light phase modulation means P-L1-2: Light input port for control light to light phase modulation means L1-2: Optical branching section ( Optical branching means)
P-C1-1: Optical input port P-C1-2: Optical input port P-C1-3: Optical output port P-C1-4: Optical output port C-2: Optical multiplexing unit (optical multiplexing means)
P-C2-1: Optical input port P-C2-2: Optical input port P-C2-3: Optical output port P-C2-4: Optical output port C-3: Optical branching unit (optical branching means)
P-C3-1: Optical input port P-C3-2: Optical input port P-C3-3: Optical output port P-C3-4: Optical output port P-Data-In: External for inputting optical signal train for data Optical input port P-ERS-In: external optical input port P-FF-In: optical signal sequence input for flip-flop control optical signal sequence input external optical input port D-D-1: optical propagation Delay difference adding unit (light propagation delay difference adding means)
DD-2: Light propagation delay difference providing unit (light propagation delay difference providing means)
MZ-2: Mach-Zehnder interference type optical intensity modulation means P-MZ-2-In: optical input port P-Data-out: optical output port for optical signal string output R-2: optical phase modulation means P-R2: Optical input port L-2 for control light to optical phase modulation means R-2: Optical phase modulation means P-L2: Optical input port for control light to optical phase modulation means L-2 C-4: Optical branching section ( Optical branching means)
P-C4-1: Optical input port P-C4-2: Optical input port P-C4-3: Optical output port P-C4-4: Optical output port P-Gate-In: Optical signal output gate open / close control light External optical input port DD-3 for signal train input: optical propagation delay difference providing unit (optical propagation delay difference providing means)
P-OP-In: optical input port P-OP-Out: optical output port OS-1: 1 × N optical switch ODL-1 to ODL-N: optical delay line O-Loop: optical waveguide loop OA: optical amplifier OS -2: 2 × 2 optical switch C-1, C-3, C-4 Optical branching unit C-2 Optical multiplexing unit 100, 110, 120 Optical multiplexing / branching unit a1, a2, a7, a8 Optical input ports a3, a4 a5, a6 Optical output port b1, b2 Multimode interference waveguide part d1, d2 Optical phase adjustment part wg1, wg2 Optical waveguide

Claims (5)

An external optical input port P-OCLK-In for inputting the clock signal light CLK-1 output from the clock signal light source, and an optical output port located on the bar side with respect to the external optical input port P-OCLK-In Two optical interference arms having P-MZ-1-bar and an optical output port P-MZ-1-cross located on the cross side, and the optical interference arm located on the optical waveguide of one of the optical interference arms Optical phase modulation means L1-1 for modulating the phase of the optical signal train propagating through the inside, and the phase of the optical signal train propagating through the optical interference arm located on the optical waveguide of the other optical interference arm Mach-Zehnder interference type light intensity modulation means MZ-1 which has an optical phase modulation means R1-1 for applying modulation to the light and functions as a Mach-Zehnder type interferometer,
An optical waveguide 18 directly or indirectly connected to an external optical input port P-Data-In for inputting an optical signal sequence Data-1 having information to be stored, and guiding the optical signal sequence Data-1.
An optical input port P-C1-1 connected to the optical waveguide 18 to which an optical signal string Data-1 from the external optical input port P-Data-In is input, and the optical output port P-MZ-1-bar Or P-C1-2 to which an optical signal train from any one of the optical output ports P-MZ-1-cross is input, and optical output ports P-C1-3, P-C1-4, Optical branching unit C-1 for branching and outputting the optical signal train input from the optical input ports P-C1-2 and P-C1-1 to the optical output ports P-C1-3 and P-C1-4 When,
An optical waveguide 14 that guides an optical signal train from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross to the optical input port P-C1-2;
The light from the optical output port P-C1-4 connected to the optical input port P-R1-1 for inputting the optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means R1-1. An optical waveguide 15R for guiding the signal train;
Light from the optical output port P-C1-3 connected to the optical input port P-L1-1 for inputting the optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means L1-1. An optical waveguide 15L for guiding the signal train;
The optical signal trains provided on the optical waveguide 15L or the optical waveguide 15R and simultaneously output from the optical output ports P-C1-3 and P-C1-4 are the optical input ports P-L1-1 and P-. An optical waveguide section DD-1 that generates an optical delay for adjusting the timing of reaching R1-1 to be greater than or equal to the pulse width of the clock signal light CLK-1 and less than the pulse repetition period;
With
As the clock signal light CLK-1, RZ (Return to Zero) type signal light is inputted from the external light input port P-OCLK-In,
When the optical signal string Data-1 synchronized with the clock of the clock signal light CLK-1 is input from the external optical input port P-Data-In, first, the input optical signal string Data-1 is changed. The phase modulation means R1-1 and L1-1 are driven to cause a phase difference in the clock signal light CLK-1 propagating through the two optical interference arms, and the clock signal light An optical signal train CLK output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross by turning on or off each pulse of CLK-1. -1-out-DMZ1 is circulated to the optical branching unit C-1 as the same data pattern as the data pattern of the optical signal sequence Data-1.
Subsequent rounds use the previous round optical signal sequence CLK-1-out-DMZ1 output from the optical output port P-MZ-1-bar, and the phase modulation means R1-1, L1-1. To cause a phase difference in the clock signal light CLK-1 propagating in the two optical interference arms, and to turn on or off each pulse of the clock signal light CLK-1. The optical signal train CLK-1-out-DMZ1 of the circumference output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross is As a data pattern identical to the data pattern of the signal sequence Data-1, the optical branching unit C-1 circulates and maintains the data pattern in the circuit,
The optical branching section C-1
A first multimode interference waveguide section having two optical input ports and two optical output ports;
A second multimode interferometric waveguide section having two optical input ports and two optical output ports;
Two optical waveguides respectively connecting two output ports of the first multimode interference waveguide section and two optical input ports of the second multimode interference waveguide section;
An optical phase adjusting unit that adjusts the phase of light that is disposed in at least one of the two optical waveguides and propagates through the waveguide;
An optical signal buffer memory circuit comprising: The optical signal buffer memory circuit according to claim 1.
Furthermore,
It is located on the optical waveguide of one of the optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-1, and is located behind the optical phase modulation means L1-1 and propagates through the optical interference arm. Optical phase modulation means L1-2 for modulating the phase of the optical signal train;
It is located on the optical waveguide of the other optical interference arm of the Mach-Zehnder interference type optical intensity modulation means MZ-1, and is located behind the optical phase modulation means R1-1 and propagates through the optical interference arm. Optical phase modulation means R1-2 for modulating the phase of the optical signal train;
An external optical input port P-FF-In for inputting an optical signal sequence FF-1 for flip-flop control of the data pattern maintained in the circuit;
An optical input port P-C3-2 and optical output ports P-C3-3, P-C3-4, and the optical signal train FF-1 input from the external optical input port P-FF-In An optical branching unit C-3 for inputting from the optical input port P-C3-2 and branching out to the optical output ports P-C3-3 and P-C3-4;
An optical waveguide 21 for guiding the optical signal string FF-1 from the external optical input port P-FF-In to the optical input port P-C3-2;
The light from the light output port P-C3-4 connected to the light input port P-R1-2 for inputting the light signal sequence for inducing the light phase modulation action to the light phase modulation means R1-2. An optical waveguide 22R for guiding the signal train;
Light from the optical output port P-C3-3 is connected to the optical input port P-L1-2 for inputting an optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means L1-2. An optical waveguide 22L for guiding the signal train;
Optical signal trains provided on the optical waveguide 22L or the optical waveguide 22R and simultaneously output from the optical output ports P-C3-3 and P-C3-4 are the optical input ports P-L1-2 and P-. An optical waveguide section DD-2 that generates an optical delay for adjusting the timing to reach R1-2 to be greater than the pulse width of the clock signal light CLK-1 and less than the pulse repetition period;
With
The optical signal string FF-1 is synchronized with the clock of the clock signal light CLK-1, is synchronized with the cycle of the data pattern, and has the same length as the data length of the data pattern. Signal sequence,
After the data pattern is maintained in the circuit, when the optical signal sequence FF-1 is input from the external optical input port P-FF-In, the input optical signal sequence FF-1 is used to The phase modulation means R1-2 and L1-2 are driven to cause a phase difference in the optical signal sequence output from the phase modulation means R1-1 and L1-1, and each pulse of the optical signal sequence is turned on. Alternatively, the optical signal train CLK-1-out-DMZ1 output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross A flip-flop having a data pattern obtained by inverting the data pattern of the optical signal sequence Data-1 is performed to circulate to the optical branching unit C-1.
Subsequent rounds are the previous rounds of the optical signal train CLK-1-out- output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross. Using the DMZ1, the phase modulation means R1-1 and L1-1 are driven to cause a phase difference in the clock signal light CLK-1 propagating through the two optical interference arms, and the clock By turning each pulse of the signal light CLK-1 on or off, the rotation output from either the light output port P-MZ-1-bar or the light output port P-MZ-1-cross The optical signal sequence CLK-1-out-DMZ1 is circulated to the optical branching unit C-1 as a data pattern obtained by inverting the data pattern of the optical signal sequence Data-1, and the data pattern The over emissions be configured to maintain in the circuit,
The optical branching unit C-1 and the optical branching unit C-3 are respectively
A first multimode interference waveguide section having two optical input ports and two optical output ports;
A second multimode interferometric waveguide section having two optical input ports and two optical output ports;
Two optical waveguides respectively connecting two output ports of the first multimode interference waveguide section and two optical input ports of the second multimode interference waveguide section;
An optical phase adjusting unit that adjusts the phase of light that is disposed in at least one of the two optical waveguides and propagates through the waveguide;
An optical signal buffer memory circuit comprising: The optical signal buffer memory circuit according to claim 2.
Furthermore,
An external optical input port P-ERS-In for inputting an optical signal string ERS-1 for erasing control for erasing the data pattern maintained in the circuit;
The optical input ports P-C2-1 and P-C2-2 and the optical output port P-C2-4 connected to the optical waveguide 18 are included, and the optical input ports P-C2-1 and P-C2-2 are included. An optical multiplexing unit C-2 for coupling the optical signal sequence input from the same optical output port P-C2-4 to the same,
An optical waveguide 16 for guiding an optical signal string from the external optical input port P-Data-In to the optical input port P-C2-1;
An optical waveguide 17 for guiding an optical signal string from the external optical input port P-ERS-In to the optical input port P-C2-2;
With
The optical signal string ERS-1 is synchronized with the clock of the clock signal light CLK-1, is synchronized with the cycle of the data pattern, and has the same length as the data length of the data pattern. Signal sequence,
After the same data pattern as the data pattern of the optical signal sequence Data-1 or an inverted data pattern is maintained in the circuit, the optical signal sequence ERS-1 is input from the external optical input port P-ERS-In. The optical signal train ERS-1 and the optical signal train CLK- output from one of the optical output port P-MZ-1-bar and the optical output port P-MZ-1-cross. 1-out-DMZ1 is used to drive the phase modulation means R1-1 and L1-1 so that all the phases of the clock signal light CLK-1 propagating in the two optical interference arms are π. Modulate,
When the optical signal sequence FF-1 is input from the external optical input port P-FF-In simultaneously with the input of the optical signal sequence ERS-1, the input optical signal sequence FF-1 is used. The phase modulation means R1-2 and L1-2 are driven to further π-modulate the phase of the optical signal sequence output from the phase modulation means R1-1 and L1-1, and the optical signal sequence is By outputting from either one of the optical output port P-MZ-1-bar and the optical output port P-MZ-1-cross, the optical output port P-MZ-1-bar or the optical output port P- It is the structure which returns to the initial state where there is no light output from either one of MZ-1-cross,
The optical multiplexing unit C-2
A first multimode interference waveguide section having two optical input ports and two optical output ports;
A second multimode interferometric waveguide section having two optical input ports and two optical output ports;
Two optical waveguides respectively connecting two output ports of the first multimode interference waveguide section and two optical input ports of the second multimode interference waveguide section;
An optical phase adjusting unit that adjusts the phase of light that is disposed in at least one of the two optical waveguides and propagates through the waveguide;
An optical signal buffer memory circuit comprising: An external optical input port P-OCLK-In for inputting the clock signal light CLK-1 output from the clock signal light source, and an optical output port located on the bar side with respect to the external optical input port P-OCLK-In Two first optical interference arms having P-MZ-1-bar and an optical output port P-MZ-1-cross located on the cross side, on the optical waveguide of one of the first optical interference arms An optical phase modulation means L1-1 for modulating the phase of the optical signal train positioned and propagating in the optical interference arm, and the optical interference arm positioned on the optical waveguide of the other first optical interference arm Mach-Zehnder interference type optical intensity modulation means MZ-1 having optical phase modulation means R1-1 for modulating the phase of the optical signal train propagating therethrough and functioning as a Mach-Zehnder type interferometer ,
An optical waveguide 18 directly or indirectly connected to an external optical input port P-Data-In for inputting an optical signal sequence Data-1 having information to be stored, and guiding the optical signal sequence Data-1.
An optical input port P-C1-1 connected to the optical waveguide 18 to which an optical signal string Data-1 from the external optical input port P-Data-In is input, and the optical output port P-MZ-1-bar Or P-C1-2 to which an optical signal train from any one of the optical output ports P-MZ-1-cross is input, and optical output ports P-C1-3, P-C1-4, Optical branching unit C-1 for branching and outputting the optical signal train input from the optical input ports P-C1-2 and P-C1-1 to the optical output ports P-C1-3 and P-C1-4 When,
An optical waveguide 14 that guides an optical signal train from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross to the optical input port P-C1-2;
The light from the optical output port P-C1-4 connected to the optical input port P-R1-1 for inputting the optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means R1-1. An optical waveguide 15R for guiding the signal train;
Light from the optical output port P-C1-3 connected to the optical input port P-L1-1 for inputting the optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means L1-1. An optical waveguide 15L for guiding the signal train;
The optical signal trains provided on the optical waveguide 15L or the optical waveguide 15R and simultaneously output from the optical output ports P-C1-3 and P-C1-4 are the optical input ports P-L1-1 and P-. An optical waveguide section DD-1 that generates an optical delay for adjusting the timing of reaching R1-1 to be greater than or equal to the pulse width of the clock signal light CLK-1 and less than the pulse repetition period;
With
As the clock signal light CLK-1, RZ (Return to Zero) type signal light is inputted from the external light input port P-OCLK-In,
When the optical signal string Data-1 synchronized with the clock of the clock signal light CLK-1 is input from the external optical input port P-Data-In, first, the input optical signal string Data-1 is changed. The phase modulation means R1-1 and L1-1 are driven to cause a phase difference in the clock signal light CLK-1 propagating through the two first optical interference arms, and Light output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross by turning on or off each pulse of the clock signal light CLK-1 The signal train CLK-1-out-DMZ1 is circulated to the optical branching unit C-1 as the same data pattern as the data pattern of the optical signal train Data-1,
Subsequent rounds are the previous rounds of the optical signal train CLK-1-out- output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross. Using DMZ1, the phase modulation means R1-1 and L1-1 are driven to cause a phase difference in the clock signal light CLK-1 propagating through the two first optical interference arms. By turning on or off each pulse of the clock signal light CLK-1, the light is output from either the light output port P-MZ-1-bar or the light output port P-MZ-1-cross. The optical signal sequence CLK-1-out-DMZ1 of the circulation is circulated to the optical branching unit C-1 as the same data pattern as the data pattern of the optical signal sequence Data-1, and the data In the optical signal the buffer memory circuit to maintain a pattern in said circuit,
Furthermore,
On the optical waveguide of one of the first optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-1, located on the rear stage side of the optical phase modulation means L1-1 and in the optical interference arm. Optical phase modulation means L1-2 for modulating the phase of the optical signal train propagating through
On the optical waveguide of the other first optical interference arm of the Mach-Zehnder interference type optical intensity modulation means MZ-1, and located on the rear stage side of the optical phase modulation means R1-1, Optical phase modulation means R1-2 for modulating the phase of the optical signal train propagating through
An external optical input port P-FF-In for inputting an optical signal sequence FF-1 for flip-flop control of the data pattern maintained in the circuit;
An optical input port P-C3-2 and optical output ports P-C3-3, P-C3-4, and the optical signal train FF-1 input from the external optical input port P-FF-In An optical branching unit C-3 for inputting from the optical input port P-C3-2 and branching out to the optical output ports P-C3-3 and P-C3-4;
An optical waveguide 21 for guiding the optical signal string FF-1 from the external optical input port P-FF-In to the optical input port P-C3-2;
The light from the light output port P-C3-4 connected to the light input port P-R1-2 for inputting the light signal sequence for inducing the light phase modulation action to the light phase modulation means R1-2. An optical waveguide 22R for guiding the signal train;
Light from the optical output port P-C3-3 is connected to the optical input port P-L1-2 for inputting an optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means L1-2. An optical waveguide 22L for guiding the signal train;
Optical signal trains provided on the optical waveguide 22L or the optical waveguide 22R and simultaneously output from the optical output ports P-C3-3 and P-C3-4 are the optical input ports P-L1-2 and P-. An optical waveguide section DD-2 that generates an optical delay for adjusting the timing to reach R1-2 to be greater than the pulse width of the clock signal light CLK-1 and less than the pulse repetition period;
An optical input port P-MZ-2-In for inputting an optical signal string output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross; , Two optical output ports P-Data-Out located on the bar side with respect to the optical input port P-MZ-2-In and two optical output ports P-MON-Out located on the cross side An optical interference arm, an optical phase modulation means L-2 for modulating the phase of an optical signal train that is located on the optical waveguide of one of the second optical interference arms and propagates through the optical interference arm, and the other And an optical phase modulation means R-2 for modulating the phase of the optical signal train which is located on the optical waveguide of the second optical interference arm and propagates through the optical interference arm, and is a Mach-Zehnder type Functions as an interferometer And Tsu Ha-Zehnder interference type light intensity modulating means MZ-2,
An optical waveguide 30 that guides an optical signal train from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross to the optical input port P-MZ-2-In When,
An external optical input port P-Gate-In for inputting an optical signal string Gate-1 for optical signal output opening / closing control for outputting an optical signal string of the data pattern maintained in the circuit; ,
An optical input port P-C4-2 and optical output ports P-C4-3 and P-C4-4, and the optical signal string Gate-1 input from the external optical input port P-Gate-In An optical branching unit C-4 for inputting from the optical input port P-C4-2 and branching out to the optical output ports P-C4-3 and P-C4-4;
An optical waveguide 41 for guiding the optical signal string Gate-1 from the external optical input / output port P-Gate-In to the optical input port P-C4-2;
An optical signal train from the optical output port P-C4-3 connected to an optical input port P-L2 for inputting a signal optical train for inducing an optical phase modulation action to the optical phase modulation means L-2. An optical waveguide 42L for guiding
An optical signal train from the optical output port P-C4-4 connected to an optical input port PR2-R2 for inputting a signal optical train for inducing an optical phase modulation action to the optical phase modulation means R-2. An optical waveguide 42R for guiding
An optical signal train provided on the optical waveguide 42L or the optical waveguide 42R and simultaneously output from the optical output ports P-C4-3 and P-C4-4 is sent to the optical input ports P-L2 and P-R2. And an optical waveguide section DD-3 that generates an optical delay for adjusting the arrival timing to be equal to or greater than the pulse width of the clock signal light CLK-1 and less than the pulse repetition period;
With
The optical signal string FF-1 is synchronized with the clock of the clock signal light CLK-1, is synchronized with the cycle of the data pattern, and has the same length as the data length of the data pattern. Signal sequence,
After the data pattern is maintained in the circuit, when the optical signal sequence FF-1 is input from the external optical input port P-FF-In, the input optical signal sequence FF-1 is used to The phase modulation means R1-2 and L1-2 are driven to cause a phase difference in the optical signal sequence output from the phase modulation means R1-1 and L1-1, and each pulse of the optical signal sequence is turned on. Alternatively, by turning off the optical signal train CLK-1-out-DMZ1 output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross, A flip-flop that performs a data pattern obtained by inverting the data pattern of the optical signal sequence Data-1 is circulated to the optical branching unit C-1,
Subsequent rounds are the previous rounds of the optical signal train CLK-1-out- output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross. Using DMZ1, the phase modulation means R1-1 and L1-1 are driven to cause a phase difference in the clock signal light CLK-1 propagating through the two first optical interference arms. By turning on or off each pulse of the clock signal light CLK-1, the light is output from either the light output port P-MZ-1-bar or the light output port P-MZ-1-cross. The optical signal sequence CLK-1-out-DMZ1 is circulated to the optical branching unit C-1 as a data pattern obtained by inverting the data pattern of the optical signal sequence Data-1, and the data pattern is An optical signal sequence output from either one of the optical output port P-MZ-1-bar and the optical output port P-MZ-1-cross is maintained in the circuit, and the optical signal sequence Data− As the same data pattern as 1, after transitioning to the repeatedly output state,
The optical signal string Gate-1 is synchronized with the clock of the clock signal light CLK-1, is synchronized with the cycle of the data pattern, and has the same length as the data length of the data pattern. Signal sequence,
When the optical signal sequence Gate-1 is input from the external optical input port P-Gate-In, the optical phase modulation means R-2 and L-2 are connected using the input optical signal sequence Gate-1. An optical signal that is driven and propagated through the two second optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-2, which is input from the optical input port P-MZ-2-In By generating a phase difference in the column, the optical signal sequence input from the optical input port P-MZ-2-In is converted into the optical output port P-Data only during the data length of the optical signal sequence Gate-1. -Output from Out,
The optical branching unit C-1, the optical branching unit C-3, and the optical branching unit C-4 are respectively
A first multimode interference waveguide section having two optical input ports and two optical output ports;
A second multimode interferometric waveguide section having two optical input ports and two optical output ports;
Two optical waveguides respectively connecting two output ports of the first multimode interference waveguide section and two optical input ports of the second multimode interference waveguide section;
An optical phase adjusting unit that adjusts the phase of light that is disposed in at least one of the two optical waveguides and propagates through the waveguide;
An optical signal buffer memory circuit comprising: The optical signal buffer memory circuit according to claim 4.
Furthermore,
An external optical input port P-ERS-In for inputting an optical signal string ERS-1 for erasing control for erasing the data pattern maintained in the circuit;
The optical input ports P-C2-1 and P-C2-2 and the optical output port P-C2-4 connected to the optical waveguide 18 are included, and the optical input ports P-C2-1 and P-C2-2 are included. An optical multiplexing unit C-2 for coupling the optical signal sequence input from the same optical output port P-C2-4 to the same,
An optical waveguide 16 for guiding an optical signal string from the external optical input port P-Data-In to the optical input port P-C2-1;
An optical waveguide 17 for guiding an optical signal string from the external optical input port P-ERS-In to the optical input port P-C2-2;
With
The optical signal string ERS-1 is synchronized with the clock of the clock signal light CLK-1, is synchronized with the cycle of the data pattern, and has the same length as the data length of the data pattern. Signal sequence,
After the same data pattern as the data pattern of the optical signal sequence Data-1 or an inverted data pattern is maintained in the circuit, the optical signal sequence ERS-1 is input from the external optical input port P-ERS-In. The optical signal train ERS-1 and the optical signal train CLK- output from one of the optical output port P-MZ-1-bar and the optical output port P-MZ-1-cross. The phase of the clock signal light CLK-1 propagating in the two first optical interference arms by driving the phase modulation means R1-1 and L1-1 using 1-out-DMZ1 Π-modulate all
When the optical signal sequence FF-1 is input from the external optical input port P-FF-In simultaneously with the input of the optical signal sequence ERS-1, the input optical signal sequence FF-1 is used. The phase modulation means R1-2 and L1-2 are driven to further π-modulate the phase of the optical signal sequence output from the phase modulation means R1-1 and L1-1, and the optical signal sequence is By outputting from either one of the optical output port P-MZ-1-bar and the optical output port P-MZ-1-cross, the optical output port P-MZ-1-bar or the optical output port P- It is the structure which returns to the initial state where there is no light output from either one of MZ-1-cross,
The optical multiplexing unit C-2 includes:
A first multimode interference waveguide section having two optical input ports and two optical output ports;
A second multimode interferometric waveguide section having two optical input ports and two optical output ports;
Two optical waveguides respectively connecting two output ports of the first multimode interference waveguide section and two optical input ports of the second multimode interference waveguide section;
An optical phase adjusting unit that adjusts the phase of light that is disposed in at least one of the two optical waveguides and propagates through the waveguide;
An optical signal buffer memory circuit comprising:

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