Optical full adder and multi-bit binary optical full adder

Abstract

This invention provides an optical full adder, comprising: a first beam combiner, adapted to receive optical signals through at least two original signal input terminals and superimpose the light intensities of the optical signals; a first nonlinear optical switch, adapted to switch the transmission path of the optical signal output from the first signal output terminal of the first beam combiner according to the intensity of the light signals; a second beam combiner, adapted to superimpose the light intensities of the optical signal input from the upper carry optical signal input terminal and the optical signal input from the weak light end optical signal input terminal; a second nonlinear optical switch, adapted to switch the transmission path of the optical signal output from the output terminal of the second beam combiner according to the intensity of the light signals; and a third beam combiner, adapted to superimpose the optical signals output from the first nonlinear optical switch and the second nonlinear optical switch to obtain the carry output optical signal. This invention also provides a multi-bit binary all-optical adder.

Description

Technical Field

[0001] This invention relates to the field of optical computing technology, specifically to an optical full adder and its multi-bit binary all-optical adder. Background Technology

[0002] The full adder is a fundamental module of arithmetic logic units and an indispensable core unit in traditional integrated circuit architectures. However, as Moore's Law approaches its limit, a framework with stronger information processing capabilities is needed. Optical communication and computing are becoming increasingly important due to their higher speed, lower cost, and higher security. In the process of information transmission and processing, the conversion of information from electricity to light and back to electricity is usually very slow, much slower than the information processing in light. Therefore, the conversion process should be minimized; in other words, as much processing and even computation as possible should be performed in the optical phase.

[0003] However, existing adders are mostly based on micro-ring modulators or photonic crystal technology, which cannot simultaneously meet the needs of all-optical processing and other applications. Summary of the Invention

[0004] To address the above problems, a first aspect of the present invention provides an optical full adder, comprising:

[0005] The first beam combiner is configured with at least two original signal input terminals and a first signal output terminal, and is suitable for inputting optical signals through the at least two original signal input terminals and superimposing the light intensities of the optical signals.

[0006] The first nonlinear optical switch is equipped with a first signal input terminal, a first strong light output terminal and a first weak light output terminal, and is suitable for switching the transmission path of the optical signal output from the first signal output terminal of the first beam combiner according to the intensity of the light.

[0007] The second beam combiner is equipped with an upper carry optical signal input terminal, a weak light end optical signal input terminal and a second signal output terminal, and is suitable for superimposing the light intensity of the optical signal input from the upper carry optical signal input terminal and the optical signal input from the weak light end optical signal input terminal.

[0008] The second nonlinear optical switch is configured with a second signal input terminal, a second strong light output terminal and a second weak light output terminal, and is suitable for switching the transmission path of the optical signal output from the output terminal of the second beam combiner according to the intensity of the light. The optical signal output from the second weak light output terminal is the local output optical signal.

[0009] The third beam combiner is equipped with at least two high-intensity light input terminals and a third signal output terminal, and is suitable for superimposing the optical signals output by the first nonlinear optical switch and the second nonlinear optical switch as a carry output optical signal.

[0010] According to an embodiment of the present invention, the first nonlinear optical switch and the second nonlinear optical switch have the same structure and are determined by a nonlinear reverse design method;

[0011] The transmission efficiency of both the first nonlinear optical switch and the second nonlinear optical switch is 66%.

[0012] According to an embodiment of the present invention, a light intensity threshold monitoring element is provided within the structure of the first nonlinear optical switch and the second nonlinear optical switch;

[0013] If the monitoring element detects that the light intensity of the light signal entering the nonlinear optical switch is less than the light intensity threshold, then the light signal entering the nonlinear optical switch will be output from the weak light output terminal.

[0014] If the monitoring element detects that the light intensity of the light signal entering the nonlinear optical switch is greater than the light intensity threshold, then the light signal entering the nonlinear optical switch will be output from the high light output terminal.

[0015] According to an embodiment of the present invention, the first beam combiner includes one of a directional coupler, a Y-branch coupler, and a multimode interference coupler;

[0016] The aforementioned second beam combiner includes one of a directional coupler, a Y-branch coupler, and a multimode interference coupler;

[0017] The aforementioned third combiner includes one of a directional coupler, a Y-branch coupler, and a multimode interference coupler.

[0018] According to an embodiment of the present invention, by controlling the intensity of the optical signal entering the beam combiner, and thereby controlling the transmission path of the optical signal entering the nonlinear optical switch, the function of an optical full adder is realized.

[0019] According to an embodiment of the present invention, the first beam combiner, the first nonlinear optical switch, the second beam combiner, the second nonlinear optical switch, and the third beam combiner are connected by optical waveguides.

[0020] The length of the optical waveguide between two adjacent optical elements is determined based on the effective distance of optical signal propagation within the optical waveguide.

[0021] The first high-intensity light output terminal of the first nonlinear optical switch and the first high-intensity light input terminal of the third beam combiner are connected by a first optical waveguide.

[0022] The upper carry optical signal input terminal of the aforementioned second beam combiner is connected to a second optical waveguide;

[0023] The aforementioned first optical waveguide includes: two curved optical waveguides and one straight optical waveguide, wherein the straight optical waveguide is located between the two curved optical waveguides;

[0024] The aforementioned second optical waveguide includes: a curved optical waveguide and a straight optical waveguide, wherein the curved optical waveguide is connected to the entrance of the aforementioned upper-level carry optical signal input terminal.

[0025] According to an embodiment of the present invention, the above-described optical full adder is fabricated on a silicon, silicon dioxide, or silicon nitride platform.

[0026] A second aspect of the present invention provides a multi-bit binary all-optical adder, constructed by multi-stage cascading using the structure described in any of the preceding claims, comprising:

[0027] An input unit is adapted to receive an optical signal to be processed and transmit the optical signal to various stages of optical full adders; wherein, the input unit includes a section of optical waveguide; the input unit is connected to at least two original signal input terminals of the first beam combiner of the multi-stage optical full adder through the optical waveguide;

[0028] In the above-mentioned multi-stage optical full adder, adjacent optical full adders are connected to the upper carry optical signal input terminal of the upper stage carry optical signal of the upper stage carry output optical signal through the third signal output terminal of the third beam combiner of the current stage optical full adder and the upper stage carry optical signal input terminal of the second beam combiner of the next stage optical full adder to obtain a carry output optical signal.

[0029] The output unit is suitable for outputting the processed optical signal. The output unit is connected to the weak light output terminal of the second nonlinear optical switch of the multi-stage optical full adder to obtain the local output optical signal.

[0030] According to an embodiment of the present invention, the cascaded stages of the optical full adders are of different numbers, forming multiple N-bit binary adders, which are then used to process the continuous addition of two sets of N-bit optical signals; where N represents an integer greater than or equal to 2.

[0031] According to an embodiment of the present invention, the above-mentioned multi-bit binary all-optical adder is fabricated on a silicon, silicon dioxide, or silicon nitride platform.

[0032] According to embodiments of the present invention, by introducing a nonlinear optical switch into an optical full adder, the transmission path of the optical signal is controlled by adjusting the light intensity, thereby obtaining different logic outputs and realizing the full adder function. Furthermore, compared with existing binary optical full adders based on microring resonators, this optical full adder avoids the use of traditional electrical components by using a nonlinear switch instead of a microring resonator, thus overcoming the electromagnetic efficiency limitations of traditional electrical components and the influence of resistors and capacitors on the optical signal. This reduces the control of the optical signal by the electrical signal, realizing an optical full adder where all optical signals participate in processing and calculation. This optical full adder has a faster response time and higher computational efficiency.

[0033] According to embodiments of the present invention, by cascading multiple optical full adders based on nonlinear optical switches into a multi-bit binary all-optical adder, the input optical signal is processed and calculated almost simultaneously from the least significant bit to the most significant bit, and then output as the final optical signal. Furthermore, compared to existing multi-bit binary adders, this cascaded structure can achieve simultaneous all-optical processing by calculating each bit of the optical signal almost simultaneously, avoiding the long response time of electrical signal modulation, and greatly improving computational efficiency. This cascaded structure can realize continuous high-speed computation of two sets of N-bit binary optical signals. Attached Figure Description

[0034] The above-described features, other objects, and advantages of the present invention will become clearer from the following description of embodiments of the invention with reference to the accompanying drawings, in which:

[0035] Figure 1 A schematic diagram of an optical full adder 100 according to an embodiment of the present invention is shown;

[0036] Figure 2 A schematic diagram illustrating the structure of a plurality of nonlinear optical switches according to an embodiment of the present invention is shown.

[0037] Figure 3 A schematic diagram illustrating the structure of a plurality of bundle combiners according to an embodiment of the present invention is shown.

[0038] Figure 4 This is a schematic diagram of a multi-bit binary all-optical adder provided in an embodiment of the present invention.

[0039] The corresponding reference numerals in the above figures are explained as follows:

[0040] 100: Optical full adder;

[0041] 110: First bundle combiner;

[0042] A: Signal input terminal;

[0043] B: Signal input terminal;

[0044] 120: First nonlinear optical switch;

[0045] 130: Second bundle combiner;

[0046] 131: Upper-level carry optical signal input terminal;

[0047] C-1: Input port for the carry optical signal from the upper level;

[0048] 132: Low-light end optical signal input terminal;

[0049] 140: Second nonlinear optical switch;

[0050] S: The output terminal of the optical signal;

[0051] 150: First optical waveguide;

[0052] 160: Third bundle combiner;

[0053] C: The output terminal of the optical signal carry;

[0054] N: Number of cascaded stages in the optical full adder;

[0055] 410: Input unit;

[0056] 420: Output unit. Detailed Implementation

[0057] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the invention. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the invention for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0058] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0059] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0060] When using expressions such as "at least one of A, B, and C", they should generally be interpreted in accordance with the meaning that is commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B, and C, etc.).

[0061] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0062] High-speed processing is one of the superior characteristics of photonics-based devices. Therefore, all-optical systems need to perform all communication steps without using electrical signals. Signal processing is a crucial step in optical systems and networks, and all optical logic devices are essential for realizing all-optical signal processing. Optical full adders, as fundamental core devices in optical signal processing, play an irreplaceable role.

[0063] Figure 1 A schematic diagram of an optical full adder 100 according to an embodiment of the present invention is shown.

[0064] like Figure 1 As shown, an exemplary embodiment of the present invention provides an optical full adder 100, including: a first beam combiner 110, a first nonlinear optical switch 120, a second beam combiner 130, a second nonlinear optical switch 140, and a third beam combiner 160. The first beam combiner 110 is configured with at least two original signal input terminals and a first signal output terminal, suitable for inputting optical signals through at least two original signal input terminals and superimposing the light intensities of the optical signals; the first nonlinear optical switch 120 is configured with a first signal input terminal, a first strong light output terminal, and a first weak light output terminal, suitable for switching the transmission path of the optical signal output from the first signal output terminal of the first beam combiner 110 according to the intensity of the light; the second beam combiner 130 is configured with an upper-level carry optical signal input terminal 131, a weak light optical signal input terminal 132, and a second signal output terminal, suitable for converting the upper-level carry optical signal input terminal... The light intensity of the optical signal input at input terminal 131 is superimposed with the light intensity of the optical signal input at input terminal 132 at the weak light end; the second nonlinear optical switch 140 is configured with a second signal input terminal, a second strong light output terminal and a second weak light output terminal, and is suitable for switching the transmission path of the optical signal output from the output terminal of the second beam combiner 130 according to the intensity of the light, wherein the optical signal output from the second weak light output terminal is the local output optical signal; the third beam combiner 160 is configured with at least two strong light input terminals and a third signal output terminal, and is suitable for superimposing the optical signals output from the first nonlinear optical switch 120 and the second nonlinear optical switch 140 as the carry output optical signal.

[0065] According to an embodiment of the present invention, by introducing a nonlinear optical switch into the optical full adder 100, the transmission path of the optical signal is controlled by adjusting the light intensity, thereby obtaining different logic outputs and realizing the full adder function. Furthermore, compared with the prior art binary optical full adders based on microring resonators, this optical full adder 100 avoids the use of traditional electrical components by using a nonlinear switch instead of a microring resonator, thus overcoming the electromagnetic efficiency of traditional electrical components and the influence of resistors and capacitors on the optical signal. This reduces the control of the optical signal by the electrical signal, realizing an optical full adder 100 in which all optical signals participate in processing and calculation. This optical full adder 100 has a faster response time and higher computational efficiency.

[0066] According to an embodiment of the present invention, optical signals are input to the A and B signal input terminals of the first beam combiner 110. After the light intensity is superimposed, the signals are output from the first signal output terminal. The signals are then input to the first nonlinear optical switch 120 via the first signal input terminal. Since the first nonlinear optical switch 120 has a certain transmission efficiency, the optical signals are attenuated and selectively output from the first strong light output terminal or the first weak light output terminal according to the magnitude of their light intensity.

[0067] According to an embodiment of the present invention, the optical signal output from the first high-intensity light output terminal passes through the first waveguide and one high-intensity light input terminal of the third beam combiner 160 and enters the third beam combiner 160, and is further superimposed with the optical signal from the other high-intensity light input terminal as a carry-out output optical signal.

[0068] According to an embodiment of the present invention, the optical signal output from the first weak light output terminal enters the second beam combiner 130 through the weak light end optical signal input terminal 132 of the second beam combiner 130; and is superimposed with the optical signal that has passed through the upper carry optical signal input terminal 131 and the second optical waveguide and entered the second beam combiner 130 in sequence, and is then output to the second signal input terminal of the second nonlinear optical switch 140 through the second signal output terminal. Since the second nonlinear optical switch 140 also has a certain transmission efficiency, after the optical signal is attenuated again, it is selectively output from the second strong light output terminal or the second weak light output terminal according to the magnitude of its light intensity.

[0069] According to an embodiment of the present invention, an optical signal is output from the second weak light output terminal as the local output optical signal; the optical signal output from the second strong light output terminal enters the third beam combiner 160 and is further superimposed with the optical signal from another strong light input terminal as the carry output optical signal.

[0070] Figure 2 The schematic diagram illustrates the structure of a plurality of nonlinear optical switches according to an embodiment of the present invention.

[0071] like Figure 2 As shown, the design area of ​​the nonlinear optical switch includes an optical signal input area, a linear transmission path, and a nonlinear transmission path. The 5μm figure is a scale bar.

[0072] According to an embodiment of the present invention, the nonlinear optical switch includes a first nonlinear optical switch 120 and a second nonlinear optical switch 140; the first nonlinear optical switch 120 and the second nonlinear optical switch 140 have the same structure and are determined by a nonlinear reverse design method;

[0073] By using the nonlinear inverse design method to determine the nonlinear optical switch, different transmission efficiencies can be set to obtain different nonlinear optical switch structures.

[0074] Preferably, the transmission efficiency of both the first nonlinear optical switch 120 and the second nonlinear optical switch 140 is 66%.

[0075] According to an embodiment of the present invention, a light intensity threshold monitoring element is provided within the structure of the first nonlinear optical switch 120 and the second nonlinear optical switch 140;

[0076] If the monitoring element detects that the light intensity of the light signal entering the nonlinear optical switch is less than the light intensity threshold, then the light signal entering the nonlinear optical switch will be output from the weak light output terminal.

[0077] If the monitoring element detects that the light intensity of the light signal entering the nonlinear optical switch is greater than the light intensity threshold, then the light signal entering the nonlinear optical switch will be output from the high light output terminal.

[0078] According to an embodiment of the present invention, the first nonlinear optical switch 120 and the second nonlinear optical switch 140 are configured with light intensity thresholds. By monitoring the relationship between the light intensity of the optical signal entering the nonlinear optical switch and the light intensity threshold, the transmission path of the optical signal is determined. Specifically, if the light intensity of the optical signal entering the nonlinear optical switch is below the threshold, it is determined to be a weak light signal, insufficient to excite the nonlinear effect of the nonlinear optical switch, and is therefore output from the weak light output terminal; if the light intensity of the optical signal entering the nonlinear optical switch is above the threshold, it is determined to be a strong light signal, capable of exciting the nonlinear effect of the nonlinear optical switch, and is therefore output from the strong light output terminal.

[0079] According to an embodiment of the present invention, assuming that the light intensity of the optical signal is represented by 1 to 10 and increases sequentially, the light intensity threshold of the nonlinear optical switch is 5; the optical signal with a light intensity of 3 is output from the weak light output end, and the optical signal with a light intensity of 6 is output from the strong light output end.

[0080] Figure 3 A schematic diagram of the structure of a plurality of bundle combiners according to an embodiment of the present invention is shown.

[0081] like Figure 3 As shown, Figure 3 Figure (a) in the diagram represents a multimode interferometric coupler. Figure 3 Figure (b) in the diagram represents a directional coupler. Figure 3 Figure (c) in the diagram represents a Y-coupler.

[0082] According to an embodiment of the present invention, the first combiner 110 includes one of a directional coupler, a Y-branch coupler, and a multimode interference coupler (MMI coupler).

[0083] The second combiner 130 includes one of a directional coupler, a Y-branch coupler, and a multimode interference coupler;

[0084] The third combiner 160 includes one of a directional coupler, a Y-branch coupler, and a multimode interference coupler.

[0085] According to an embodiment of the present invention, preferably, the first combiner 110 and the second combiner 130 are both MMI couplers, so as to better realize the superposition of the optical signals input at the signal input terminal, thereby reducing optical loss.

[0086] According to an embodiment of the present invention, by controlling the intensity of the optical signal entering the beam combiner, it is determined that a single input optical signal is a weak optical signal and multiple input optical signals are strong optical signals, thereby controlling the transmission path of the optical signal entering the nonlinear optical switch. Different logic outputs can be obtained from different output ports of the nonlinear optical switch, thereby realizing the function of the optical full adder 100.

[0087] According to an embodiment of the present invention, the first beam combiner 110, the first nonlinear optical switch 120, the second beam combiner 130, the second nonlinear optical switch 140, and the third beam combiner 160 are connected by optical waveguides.

[0088] The length of the optical waveguide between two adjacent optical elements is determined based on the effective distance of optical signal propagation within the optical waveguide; this ensures phase matching of the optical signal at the input of the beam combiner, so as to satisfy the effective superposition of the optical signal intensity.

[0089] The first high-intensity light output terminal of the first nonlinear optical switch 120 and the first high-intensity light input terminal of the third beam combiner 160 are connected by the first optical waveguide 150.

[0090] The upper carry optical signal input terminal 131 of the second beam combiner 130 is connected to a second optical waveguide.

[0091] The first optical waveguide 150 includes: two curved optical waveguides and one straight optical waveguide, wherein the straight optical waveguide is located between the two curved optical waveguides;

[0092] The second optical waveguide includes a curved optical waveguide and a straight optical waveguide, wherein the curved optical waveguide is connected to the entrance of the upper carry optical signal input terminal 131.

[0093] According to an embodiment of the present invention, the optical full adder 100 is fabricated on a silicon, silicon dioxide or silicon nitride platform, and therefore has the characteristics of high stability, low loss and small size due to compact structure.

[0094] According to embodiments of the present invention, the working principle of the optical full adder 100 is described in detail through the following examples:

[0095] Reference Figure 1 The optical full adder 100 has three optical signal input terminals and two optical signal output terminals. The logic representation of having an optical signal is "1", and the logic representation of not having an optical signal is "0".

[0096] When there is no input (logic "0") at signal terminal A, no input (logic "0") at signal terminal B, and no input (logic "0") at port C-1, then there is no output (logic "0") at port S and no output (logic "0") at port C.

[0097] When there is an input optical signal with an intensity of 3 (logic "1") at signal terminal A, no input at signal terminal B (logic "0"), and no input at port C-1 (logic "0"), the optical signal is determined to be a weak optical signal. After attenuation by the first nonlinear optical switch 120, an optical signal with an intensity of 2 is output from the first weak optical output terminal. Subsequently, it enters the second beam combiner 130 and is output from the second weak optical output terminal of the second nonlinear optical switch 140. The S port outputs an optical signal with an intensity of 1.33 (logic "1"), and the C port has no output (logic "0").

[0098] When there is no input at signal terminal A (logic "0"), a light signal with an intensity of 3 at signal terminal B (logic "1"), and no input at port C-1 (logic "0"), the light signal is determined to be a weak light signal. After attenuation by the first nonlinear optical switch 120, a light signal with an intensity of 2 is output from the first weak light output terminal. This signal then enters the second beam combiner 130 and is output from the second weak light output terminal of the second nonlinear optical switch 140. Port S outputs a light signal with an intensity of 1.33 (logic "1"), while port C has no output (logic "0").

[0099] When there is an input optical signal with an intensity of 3 (logic "1") at signal A and signal B, and no input at port C-1 (logic "0"), the light intensity is superimposed to 6 by the first beam combiner 110. This superimposed signal is determined to be a strong light signal. After attenuation by the first nonlinear optical switch 120, an optical signal with an intensity of 4 is output from the first strong light output terminal. Subsequently, it is output from the third signal output terminal of the third beam combiner 160. There is no output at port S (logic "0"), and port C outputs an optical signal with an intensity of 4 (logic "1").

[0100] When there is no input at signal terminal A (logic "0"), no input at signal terminal B (logic "0"), and a light signal with an intensity of 4 at port C-1 (logic "1"), the light signal is determined to be a weak light signal. The light signal passes through the second beam combiner 130 and is input to the second nonlinear optical switch 140. After being attenuated by the second nonlinear optical switch 140, it is output from the second weak light output terminal. Port S outputs a light signal with an intensity of 2.64 (logic "1"), and port C has no output (logic "0").

[0101] When there is an input optical signal with an intensity of 3 (logic "1") at signal terminal A, no input at signal terminal B (logic "0"), and an input optical signal with an intensity of 4 (logic "1") at port C-1, the optical signal with an intensity of 3 is attenuated to 2 after passing through the first beam combiner 110 and the first nonlinear optical switch 120. It is then superimposed with the carry optical signal with an intensity of 4 to form an optical signal with an intensity of 6, which is input to the second nonlinear optical switch 140. After attenuation, the optical signal with an intensity of 4 is output from the second strong light output terminal and output from the third signal output terminal of the third beam combiner 160. There is no output at the S terminal (logic "0"), and the C port outputs an optical signal with an intensity of 4 (logic "1").

[0102] When there is no input at signal terminal A (logic "0"), a light signal with an intensity of 3 at signal terminal B (logic "1"), and a carry light signal with an intensity of 4 at port C-1 (logic "1"), the light signal with an intensity of 3 becomes an intensity of 2 after passing through the first combiner 110 and the first nonlinear optical switch 120. This intensity is then superimposed with the carry light signal with an intensity of 4 to form an light signal with an intensity of 6, which is then input to the second nonlinear optical switch 140. After attenuation, the light signal with an intensity of 4 is output from the second strong light output terminal and from the third signal output terminal of the third combiner 160. There is no output at signal terminal S (logic "0"), and the light signal with an intensity of 4 is output from port C (logic "1").

[0103] When there is an input optical signal with an intensity of 3 (logic "1") at signal A, an input optical signal with an intensity of 3 (logic "1") at signal B, and an input optical signal with an intensity of 4 (logic "1") at port C-1, the optical intensities of signals A and B are superimposed to 6 by the first beam combiner 110, and an optical signal with an intensity of 4 is output from the first strong light output terminal of the first nonlinear optical switch 120. The signal is also output from the third signal output terminal of the third beam combiner 160. The optical signal with an intensity of 4 at port C-1 passes through the second beam combiner 130, is input to the second nonlinear optical switch 140, and after attenuation, is output from the second weak light output terminal. Port S outputs an optical signal with an intensity of 2.64 (logic "1"), and port C outputs an optical signal with an intensity of 4 (logic "1").

[0104] According to an embodiment of the present invention, and in conjunction with the above-described working principle of the optical full adder 100, the truth table for the three-valued binary addition calculation can be obtained as shown in Table 1.

[0105] Table 1

[0106]

[0107] Figure 4 This is a schematic diagram of a multi-bit binary all-optical adder provided in an embodiment of the present invention.

[0108] like Figure 4 As shown, an exemplary embodiment of the present invention also provides a multi-bit binary all-optical adder, including: an input unit 410, a multi-stage optical full adder 100, and an output unit 420. The input unit 410 is adapted to receive the optical signal to be processed and transmit the optical signal to each stage of the optical full adder 100. The input unit 410 includes an optical waveguide. The input unit 410 is connected to at least two original signal input terminals of the first beam combiner 110 of the multi-stage optical full adder 100 through the optical waveguide. In the multi-stage optical full adder 100, adjacent optical full adders 100 are connected to the upper carry optical signal input terminal 131 of the second beam combiner 130 of the next stage optical full adder 100 through the third signal output terminal of the third beam combiner 160 of the current stage optical full adder 100, to obtain a carry output optical signal. The output unit 420 is adapted to output the processed optical signal. The output unit 420 is connected to the weak light output terminal of the second nonlinear optical switch 140 of the multi-stage optical full adder 100 to obtain the local output optical signal.

[0109] According to an embodiment of the present invention, by cascading multiple optical full adders 100 based on nonlinear optical switches into a multi-bit binary all-optical adder, the input optical signal is processed and calculated almost simultaneously from the least significant bit to the most significant bit, and then output as the final optical signal. Furthermore, compared with existing multi-bit binary adders, this cascaded structure can achieve simultaneous all-optical processing by calculating each bit of the optical signal almost simultaneously, avoiding the long response of electrical signal modulation, and greatly improving computational efficiency. This cascaded structure can realize continuous high-speed computation of two sets of N-bit binary optical signals.

[0110] According to embodiments of the present invention, the optical full adders 100 can be cascaded at different numbers to form multiple N-bit binary all-optical adders with different structures. Therefore, by changing the number of cascaded stages of the optical full adders 100, the structure of the N-bit binary all-optical adders can be controlled, extending them into different structures. Each N-bit binary all-optical adder can process continuous addition operations of two sets of N-bit optical signals; where N represents an integer greater than or equal to 2.

[0111] According to an embodiment of the present invention, the N-bit binary all-optical adder is easier to integrate and can perform binary addition of any number of bits as needed, thus having greater scalability.

[0112] According to an embodiment of the present invention, each stage of the optical full adder 100 processes one bit of binary addition operation of optical signal A and optical signal B, and can obtain the local output optical signal and the carry output optical signal.

[0113] According to an embodiment of the present invention, for the first-stage optical full adder 100, its C-1 port does not need to be connected to an input optical signal; for the Nth-stage optical full adder 100, the optical signal output from its C port is the highest bit of a multi-bit binary output optical signal and is not connected to the input port of the next stage. For the nth stage (1 < n < N), its C-1 port is connected to the C port of the previous stage, and its C port is connected to the C-1 port of the next stage.

[0114] According to an embodiment of the present invention, two sets of N-bit binary optical signals, from low to high bits, are sequentially input into the input unit 410. After being processed by an N-stage binary all-optical adder, the processed optical signals are output from the output unit 420. This process involves sequential and multi-stage cascaded operations to achieve continuous high-speed processing of the two sets of N-bit binary optical signals.

[0115] According to embodiments of the present invention, the multi-bit binary all-optical adder is fabricated on a silicon, silicon dioxide, or silicon nitride platform, and therefore has the characteristics of high stability, low loss, and small size due to high integration.

[0116] According to an embodiment of the present invention, the working principle of the multi-bit binary all-optical adder is the same as that of the optical full adder 100. First, the optical signal to be processed is input from the input unit 410, and the superimposed value after step-by-step processing and calculation is used as the final high-bit output optical signal.

[0117] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An optical full adder, comprising: The first beam combiner is configured with at least two original signal input terminals and a first signal output terminal, and is suitable for inputting optical signals through the at least two original signal input terminals and superimposing the light intensity of the optical signals; The first nonlinear optical switch is equipped with a first signal input terminal, a first strong light output terminal and a first weak light output terminal, and is suitable for switching the transmission path of the optical signal output from the first signal output terminal of the first beam combiner according to the intensity of the light. The second beam combiner is configured with an upper carry optical signal input terminal, a weak light optical signal input terminal and a second signal output terminal. The weak light optical signal input terminal of the second beam combiner is connected to the first weak light output terminal of the first nonlinear optical switch. The second beam combiner is suitable for superimposing the light intensity of the optical signal input from the upper carry optical signal input terminal and the optical signal input from the weak light optical signal input terminal. The second nonlinear optical switch is configured with a second signal input terminal, a second strong light output terminal and a second weak light output terminal, and is suitable for switching the transmission path of the optical signal output from the output terminal of the second beam combiner according to the intensity of the light. The optical signal output from the second weak light output terminal is the local output optical signal. The third beam combiner is equipped with at least two high-intensity light input terminals and a third signal output terminal. The two high-intensity light input terminals of the third beam combiner are respectively connected to the first high-intensity light output terminal of the first nonlinear optical switch and the second high-intensity light output terminal of the second nonlinear optical switch. The third beam combiner is suitable for superimposing the optical signals output by the first nonlinear optical switch and the second nonlinear optical switch as a carry output optical signal.

2. The optical full adder of claim 1, wherein, The first nonlinear optical switch and the second nonlinear optical switch have the same structure and are determined by a nonlinear reverse design method. The transmission efficiency of both the first nonlinear optical switch and the second nonlinear optical switch is 66%.

3. The optical full adder according to claim 2, wherein, Both the first and second nonlinear optical switches have light intensity threshold monitoring elements installed within their structures. If the monitoring element detects that the light intensity of the light signal entering the nonlinear optical switch is less than the light intensity threshold, then the light signal entering the nonlinear optical switch will be output from the weak light output terminal. If the monitoring element detects that the light intensity of the light signal entering the nonlinear optical switch is greater than the light intensity threshold, then the light signal entering the nonlinear optical switch will be output from the high light output terminal.

4. The optical full adder according to claim 1, wherein, The first beam combiner includes one of a directional coupler, a Y-branch coupler, and a multimode interference coupler; The second beam combiner includes one of a directional coupler, a Y-branch coupler, and a multimode interference coupler; The third combiner includes one of a directional coupler, a Y-branch coupler, and a multimode interference coupler.

5. The optical full adder according to claim 3 or 4, wherein, By controlling the intensity of the optical signal entering the beam combiner, and thus controlling the transmission path of the optical signal entering the nonlinear optical switch, the function of an optical full adder is realized.

6. The optical full adder according to claim 1, wherein, The first beam combiner, the first nonlinear optical switch, the second beam combiner, the second nonlinear optical switch, and the third beam combiner are connected by optical waveguides. The length of the optical waveguide between two adjacent optical elements is determined based on the effective distance of optical signal propagation within the optical waveguide; The first high-intensity light output terminal of the first nonlinear optical switch is connected to a high-intensity light input terminal of the third beam combiner via a first optical waveguide. The upper carry optical signal input terminal of the second beam combiner is connected to a second optical waveguide; The first optical waveguide includes: two curved optical waveguides and one straight optical waveguide, wherein the straight optical waveguide is located between the two curved optical waveguides; The second optical waveguide includes a curved optical waveguide and a straight optical waveguide, wherein the curved optical waveguide is connected to the entrance of the upper-level carry optical signal input terminal.

7. The optical full adder according to claim 1, wherein the optical full adder is fabricated on a silicon, silicon dioxide or silicon nitride platform.

8. A multi-bit binary all-optical adder, constructed by cascading multiple stages of an optical full adder as described in any one of claims 1 to 7, comprising: An input unit is adapted to receive an optical signal to be processed and transmit the optical signal to various stages of optical full adders; wherein, the input unit includes a section of optical waveguide; the input unit is connected to at least two original signal input terminals of the first beam combiner of the multi-stage optical full adder through the optical waveguide; The multi-stage optical full adder is wherein two adjacent optical full adders are connected to the upper carry optical signal input terminal of the second beam combiner of the next stage optical full adder through the third signal output terminal of the third beam combiner of the current stage optical full adder, so as to obtain a carry output optical signal. An output unit is used to output the processed optical signal, wherein the output unit is connected to the weak light output terminal of the second nonlinear optical switch of the multi-stage optical full adder to obtain the local output optical signal.

9. The multi-bit binary all-optical adder according to claim 8, wherein, The cascaded stages of optical full adders vary, forming multiple N-bit binary adders, which then process the continuous addition of two sets of N-bit optical signals; where N represents an integer greater than or equal to 2.

10. The multi-bit binary all-optical adder according to claim 8, wherein, The multi-bit binary all-optical adder is fabricated on a silicon, silicon dioxide, or silicon nitride platform.

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