An Optical-Based PRBS Pseudo-Random Code Generator

Abstract

This invention relates to an optical-based PRBS pseudo-random code generator, belonging to the field of pseudo-random code generation technology. The pseudo-random code generator includes a first optical path, a beam splitter, a first delay line, a second delay line, a beam combiner, a second optical path, and an optical path control module. The beam splitter splits the light from the first optical path into two beams, which then pass through the two delay lines and enter the beam combiner, and are output to the control terminal of the optical path control module. The optical output terminal of the optical path control module is controlled by the control terminal. When both delay lines simultaneously output optical signals or simultaneously have no optical signal output, the optical output terminal outputs no optical signal. When both delay lines simultaneously have optical signal output on one and only one path, the optical output terminal outputs monochromatic light, which enters the first optical path. Light at any position on the first optical path is used as the PRBS pseudo-random code. This invention uses optical devices to generate arbitrary PRBS pseudo-random codes, overcoming the problems of high complexity and low speed by leveraging the characteristic of photons "propagation is computation".

Description

Technical Field

[0001] This invention belongs to the field of pseudo-random code generation technology, and more specifically, relates to an optical PRBS pseudo-random code generator. Background Technology

[0002] Traditional PRBS (Pseudo-Random Binary Sequence) pseudo-random codes are generated through cyclic left shifts and XOR operations on a linear feedback shift register (LFSR). By varying the bits in the register according to a predefined pattern, a long-period, seemingly random binary sequence is generated, which is of great significance in communication, testing, and data transmission. As a predictable binary sequence generated by a deterministic algorithm, PRBS is commonly used in system testing to evaluate channel performance and data transmission reliability, and is also used in cryptography to generate keystreams. Its applications in spectrum analysis, secure communication, and noise testing make PRBS an indispensable tool in digital communication and information technology, providing efficient and controllable pseudo-randomness for various applications.

[0003] In electronic hardware implementation, the PRBS order is equivalent to the number of registers in the LSFR. Therefore, as the PRBS order increases, the number of MOSFETs in the LSFR also increases linearly. This may have a certain impact on the complexity of the circuit. The relatively high frequency clock signal and a large number of logic gate operations may also introduce power supply noise. In addition, the PRBS code generation rate is also limited by the clock frequency. Especially for systems requiring high speed and low power consumption, a careful trade-off between the complexity of the circuit design and performance requirements is necessary.

[0004] Therefore, it is of great significance to develop a simple and high-speed PRBS pseudo-random code generator. Summary of the Invention

[0005] In view of the above-mentioned defects or improvement needs of the existing technology, the present invention provides an optical PRBS pseudo-random code generator, which aims to realize the generation of arbitrary PRBS pseudo-random codes using optical devices, and overcomes the problems of high complexity and low speed by taking advantage of the characteristic of photons that "propagation is computation".

[0006] An optical PRBS pseudo-random code generator includes a first optical path, a beam splitter, a first delay line, a second delay line, a beam combiner, a second optical path, and an optical path control module. The optical path control module includes an optical input terminal, an optical output terminal, and a control terminal.

[0007] The beam splitter splits the light from the first optical path into two beams, which then enter the beam combiner via the first delay line and the second delay line, respectively. The combined light output from the beam combiner enters the control terminal of the optical path control module via the second optical path. The optical input terminal of the optical path control module receives monochromatic light of a fixed wavelength, and the optical output terminal is controlled by the control terminal. When the first delay line and the second delay line simultaneously output optical signals or simultaneously do not output optical signals, the control terminal controls the optical output terminal to not output optical signals. When the first delay line and the second delay line have optical signal outputs on only one of them at the same time, the control terminal controls the optical output terminal to output the monochromatic light and enter the first optical path.

[0008] The delay of the first delay line is τ1, and the delay of the second delay line is τ2, where τ2-τ1=m*Δt, and m is the number of bits that differ between the two symbols in the XOR calculation performed in the PRBS pseudo-random code generator, and the symbol width is... r is the order of the PRBS pseudo-random code, τ delay1 The time taken for the optical signal to return to the starting point of the first optical path after passing through the first optical path, beam splitter, first delay line, beam combiner, second optical path and optical path control module;

[0009] An initial excitation port is set at any position on the first or second optical path to receive an initial excitation optical signal with a pulse width of Δt. An output port on the first optical path is set at any position on the first optical path to receive the result of the PRBS pseudo-random code generator. When there is an optical signal at the output port, the data is "1" and when there is no optical signal at the output port, the data is "0".

[0010] In one embodiment, the optical path control module includes a photodiode, a transimpedance amplifier, and a microring resonator. The photodiode is used to convert the optical signal output from the second optical path into a current signal. The transimpedance amplifier is used to convert the current signal into an amplified voltage signal and use it as a control signal for the microring resonator. The input terminal of the microring resonator serves as the optical input terminal of the optical path control module to receive the monochromatic light, and the output terminal of the microring resonator serves as the optical output terminal of the optical path control module.

[0011] In one embodiment, the optical path control module includes a photodiode, a transimpedance amplifier, and a Mach-Zehnder interferometer. The photodiode is used to convert the optical signal output from the second optical path into a current signal. The transimpedance amplifier is used to convert the current signal into an amplified voltage signal and use it as a control signal for the Mach-Zehnder interferometer. One of any two input ports of the Mach-Zehnder interferometer serves as the optical input port of the optical path control module to receive the monochromatic light, and one of any two output ports of the Mach-Zehnder interferometer serves as the optical output port of the optical path control module.

[0012] In one embodiment, the optical path control module includes a π phase shifter and an all-optical switch. The π phase shifter is located at the output end of the first delay line or the second delay line. The control end of the all-optical switch serves as the control end of the optical path control module. The input end of the all-optical switch serves as the optical input end of the optical path control module to receive the monochromatic light. The output end of the all-optical switch serves as the optical output end of the optical path control module.

[0013] In one embodiment, the beam combiner is a Y-type beam combiner, a directional coupler, or a multimode interferometer with optical beam combining function.

[0014] In one embodiment, the beam splitter is a Y-type beam splitter with optical beam splitting function, or a directional coupler or a multimode interferometer.

[0015] In one embodiment, a beam splitter is further provided on the first optical path, which is used to split a beam from the first optical path as the output of the PRBS pseudo-random code generator.

[0016] In one embodiment, the beam splitter is a 2:8 type beam splitter.

[0017] In one embodiment, an initial excitation source is further included for applying an initial excitation optical signal with a pulse width of Δt to the initial excitation port.

[0018] In one embodiment, a monochromatic laser is also included for applying monochromatic light of a fixed wavelength to the optical input terminal of the optical path control module.

[0019] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:

[0020] The optical-based PRBS pseudo-random code generator proposed in this invention uses a beam splitter, a first delay line, a second delay line, and a beam combiner. The beam splitter divides the optical signal into two paths, which pass through different delay lines and reach the beam combiner at different times. The output time of the same optical signal after passing through the first delay line is earlier than the output time after passing through the second delay line by m symbol lengths. Each optical signal represents one symbol. That is, when the r-th symbol is output from the first delay line, the rm-th symbol is still output from the second delay line. Therefore, the beam combiner combines the r-th and rm-th symbols. When both the r-th and rm-th bits correspond to optical signals or both correspond to no optical signals, the output of the optical path control module has no optical signal output. That is, when the r-th and rm-th bits are 00 or 11, the result is 0. When exactly one of the r-th and rm-th bits corresponds to an optical signal, the output of the optical path control module has an optical signal output. That is, when the r-th and rm-th bits are 01 or 10, the result is 1. This realizes the XOR operation of the r-th and rm-th bits of the PRBS pseudo-random code generator, generating PRBS pseudo-random codes.

[0021] On the one hand, the aforementioned PRBS pseudo-random code generator uses optical transmission delay, which can adapt to different PRBS digit types and code stream rates. It only requires adjusting the delay line length without increasing the number of additional optical components, and can realize the generation of large-cycle PRBS codes.

[0022] On the other hand, the total computing speed of the aforementioned PRBS pseudo-random code generator is only limited by the time constant of carrier diffusion in optoelectronic devices. Theoretically, the speed can reach the order of 40 Gbit / s or even higher, which is a significant improvement over the traditional method of using feedback shift registers and XOR gates.

[0023] Furthermore, the core of the aforementioned PRBS pseudo-random code generator can be integrated onto a silicon photonic chip, giving it the advantage of integration with other silicon-based devices and strong scalability. Attached Figure Description

[0024] Figure 1 A schematic diagram of a traditional PRBS pseudo-random code generator;

[0025] Figure 2 This is a partial output timing diagram of PRBS7;

[0026] Figure 3 This is a partial output timing diagram of PRBS9;

[0027] Figure 4 This is a schematic diagram of the PRBS pseudo-random code generator in Example 1;

[0028] Figure 5 The curve shows the transmittance at the lower end of the microring resonator as a function of voltage.

[0029] Figure 6 This is a schematic diagram of the PRBS pseudo-random code generator in Example 2;

[0030] Figure 7 The curve showing the transmittance at the output of the Mach-Zehnder interferometer as a function of power;

[0031] Figure 8 This is a schematic diagram of the PRBS pseudo-random code generator in Example 3;

[0032] Figure 9 This is a schematic diagram of a π phase shifter that causes two beams of light to coherently cancel each other out. Detailed Implementation

[0033] To facilitate understanding of this application and to make the aforementioned objectives, features, and advantages of this application more apparent, a detailed description of specific embodiments of this application is provided below in conjunction with the accompanying drawings. Numerous specific details are set forth in the following description to provide a thorough understanding of this application, and preferred embodiments are shown in the accompanying drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application. This application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application; therefore, this application is not limited to the specific embodiments disclosed below.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. In the description of this application, "several" means at least one, such as one, two, etc., unless otherwise explicitly specified.

[0035] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0037] To facilitate understanding of this invention, a brief introduction to the PRBS pseudo-random code generator is given first. The conventional format of PRBS pseudo-random code is PRBSr, where r represents the number of shift registers. Common PRBS pseudo-random codes include PRBS7, PRBS9, PRBS11, PRBS15, and PRBS32. For example, PRBS7 indicates that the number of shift registers is 7, and its primitive polynomial is X7 + X6 + 1. This means that the data of the 7th shift register is used as the pseudo-random code. The shifting rule is that the data of the i-th shift register is passed to the (i+1)-th shift register. The data of the 7th shift register is XORed with the data of the 6th shift register, and this data is used as the new input data of the 1st shift register. This data is shifted 6 times and then output. For example, PRBS9 indicates that the number of shift registers is 9, and its primitive polynomial is X9 + X5 + 1. This means that the data from the 9th shift register is used as the pseudo-random code, and the shift rule is that the data from the i-th shift register is passed to the (i+1)-th shift register. The data from the 9th shift register is XORed with the data from the 5th shift register, and this XORed data is used as the new input data for the 1st shift register. Figure 1 The diagram shows the structure of a traditional PRBS pseudo-random code generator, which is an m+n order PRBS pseudo-random code generator. The m-th bit and the (n+m)-th bit are XORed together to form the updated first bit. The first bit is then gradually shifted to the right and finally output. Figure 2 The figure shows a partial output timing diagram of PRBS7. Figure 3 The diagram shows a partial output timing diagram of PRBS9.

[0038] This invention improves upon existing PRBS pseudo-random code generators by using optical devices to generate arbitrary PRBS pseudo-random codes. The resulting generator has a simple structure and high generation speed. The PRBS pseudo-random code generator described in this invention will be illustrated below with specific embodiments.

[0039] Example 1

[0040] like Figure 4 The diagram shown is a schematic diagram of the PRBS pseudo-random code generator in Example 1.

[0041] refer to Figure 4As shown, the PRBS pseudo-random code generator includes a first optical path 32, a beam splitter 9, a first delay line 10, a second delay line 11, a beam combiner 12, a second optical path 31, and an optical path control module (not shown in the figure). The beam splitter 9 splits the light from the first optical path 32 into two beams, which then pass through the first delay line 10 and the second delay line 11 respectively before entering the beam combiner 12. The combined light output from the beam combiner 12 then enters the control terminal of the optical path control module via the second optical path 31. The optical input terminal of the optical path control module receives monochromatic light of a fixed wavelength, and the optical output terminal is controlled by the control terminal. When the first delay line 10 and the second delay line 11 simultaneously output optical signals or simultaneously do not output optical signals, the control terminal controls the optical output terminal to not output optical signals. When the first delay line 10 and the second delay line 11 have optical signal outputs on only one path at the same time, the control terminal controls the optical output terminal to output monochromatic light and enter the first optical path 32. The delay of the first delay line 10 is τ1, and the delay of the second delay line 11 is τ2. τ2-τ1=m*Δt, where m is the number of bits that differ between the two symbols in the XOR calculation performed in the PRBS pseudo-random code generator, and the symbol width is... r is the order of the PRBS pseudo-random code, τ delay1 This is the time it takes for the optical signal to return to the starting point of the first optical path 32 after passing through the first optical path 32, beam splitter 9, first delay line 10, beam combiner 12, second optical path 31, and optical path control module. An arbitrary position on either the first optical path 32 or the second optical path 31 is used as the initial excitation port, which receives an initial excitation optical signal with a pulse width of Δt. An arbitrary position on the first optical path 32 is used as the result output terminal of the PRBS pseudo-random code generator. When there is an optical signal at the result output terminal, it indicates that the data is "1"; when there is no optical signal at the result output terminal, it indicates that the data is "0".

[0042] Specifically, the PRBS pseudo-random code generator can be viewed as having two closed-loop cavities. The first cavity is a transmission cavity composed of the first optical path 32, beam splitter 9, first delay line 10, beam combiner 12, second optical path 31, and optical path control module. The second cavity is a transmission cavity composed of the first optical path 32, beam splitter 9, second delay line 11, beam combiner 12, second optical path 31, and optical path control module. The two cavities share a common channel except for the delay lines, because the difference in delay between the two cavities lies in the difference in delay lines. The total delay of the first cavity is τ. delay1 The total delay of the second cavity is τ delay2 ,

[0043] Where, τ delay1These can be design parameters, depending on the specific structural design of the first cavity. The values ​​of m and r are determined based on the type of PRBS pseudo-random code actually selected for implementation. Once the type of PRBS pseudo-random code is determined, m and r are determined, and the delay difference between the first delay line 10 and the second delay line 11 is determined.

[0044] For example, to generate a PRBS7 pseudo-random code, r = 7, the XOR operation is performed on the 6th and 7th bits, and m = 1. In this case, since the PRBS7 pseudo-random code has 7 code elements, the length of each code element in the first cavity is... The delay difference between the second delay line 11 and the first delay line 10 is the delay of the 6th and 7th bits, which is τ2-τ1=Δt.

[0045] For example, to generate a PRBS9 pseudo-random code, r = 9, the XOR operation is performed on the 5th and 9th bits, and m = 4. In this case, since the PRBS9 pseudo-random code has 9 code elements, the length of each code element in this first cavity is... The delay difference between the second delay line 11 and the first delay line 10 is the delay of the 5th and 9th bits of the code, which is τ2-τ1=4Δt.

[0046] Due to the delay difference design of the first delay line 10 and the second delay line 11, the outputs of the first delay line 10 and the second delay line 11 can be considered to differ by m bits. Moreover, the output bits of the first delay line 10 lead the output bits of the second delay line 11 by m bits. When the first delay line 10 outputs the r-th bit, the second delay line 11 outputs the rm-th bit. The r-th bit and the rm-th bit are combined by the beam combiner 12 and the optical path control module. When the r-th bit and the rm-th bit are represented as 00 or 11 (0 indicates the presence of an optical signal, and 1 indicates the absence of an optical signal), the optical path control module outputs 0. When the r-th bit and the rm-th bit are represented as 01 or 10, the optical path control module outputs 1. This realizes the XOR operation of the r-th bit and the rm-th bit, and outputs the operation result as a PRBS pseudo-random code, which is detected from the first optical path.

[0047] Understandably, when starting the PRBS pseudo-random code generator, an initial excitation optical signal with a pulse width of Δt must be applied to the first optical path 32 or the second optical path 32, and then the PRBS pseudo-random code generator can continuously output PRBS pseudo-random codes.

[0048] In this embodiment, the optical path control module 2 includes a photodiode 4, a transimpedance amplifier 5, and a micro-ring resonator 6. The photodiode 4 is used to acquire the optical signal output from the second optical path 31 and convert it into a current signal. The transimpedance amplifier 5 is used to convert the current signal into an amplified voltage signal and use it as a control signal for the micro-ring resonator 6. The input end of the micro-ring resonator 6 serves as the optical input end of the optical path control module, receiving monochromatic light. The download end of the micro-ring resonator 6 serves as the optical output end of the optical path control module. When the PRBS pseudo-random code generator is running, the light output from the beam combiner 12 is incident on the photodiode 4, and the current generated is converted into a voltage, amplified, and then applied to the micro-ring resonator 6. At this time, charge carriers are injected into the waveguide of the micro-ring waveguide, causing a change in the refractive index of the waveguide, thereby adjusting the resonance peak of the micro-ring resonator 6, thereby controlling the transmittance of its download end, and subsequently controlling whether an optical signal returns to the first optical path. Figure 5 The figure shows the curve of transmittance at the lower end of the microring resonator as a function of voltage. It can be seen from the figure that for a fixed wavelength of monochromatic light λ input to the microring resonator, when the applied voltage is controlled to V... λ At peak transmittance, the download end has light output; however, when the applied voltage is too high or too low, the transmittance is very low, and there is virtually no light output. Utilizing this characteristic, when only one of the first delay line 10 and the second delay line 11 has an optical signal output at any given time, the optical signal can be converted into a voltage of V. λ This ensures that the transmittance at the download end is at its peak, resulting in light output. The operational logic is as follows: when the input is 01 or 10, the output is 1. However, when neither the first delay line 10 nor the second delay line 11 outputs any light signal, the voltage converted from this light signal is less than V. λ The download end has low transmittance and virtually no light output. The operational logic is as follows: when the input is 00, the output is 0. However, when both the first delay line 10 and the second delay line 11 have optical signal outputs, the voltage converted from this optical signal is greater than V. λ The transmittance of the download end is low, and there is basically no light output. The operation logic is as follows: when the input is 11, the output is 0. Therefore, based on the design of the above optical path control module and delay line, a specific bit XOR operation can be achieved to generate PRBS pseudo-random code.

[0049] In this invention, the beam splitter 9 is capable of splitting one beam of light into two beams. In some embodiments, the beam splitter 9 can be a Y-type beam splitter with optical beam splitting function, or a directional coupler or a multimode interferometer.

[0050] In this invention, the beam splitter 12 is capable of splitting two beams into one beam. In some embodiments, the beam splitter 12 can be a Y-type beam splitter with optical beam combining function, or a directional coupler or a multimode interferometer.

[0051] In this invention, any position on the first optical path 32 is used as the output terminal of the PRBS pseudo-random code generator. In some embodiments, a beam splitter 13 can be provided on the first optical path 32. The beam splitter 13 is used to split one beam from the first optical path 32 as the output of the PRBS pseudo-random code generator. It is understood that the beam splitter 13 splits a small portion of the light used as output, and has virtually no impact on the light in the first optical path 32. For example, the beam splitter 13 can be a 2:8 type beam splitter.

[0052] In this invention, any position of the first optical path 32 or the second optical path 31 is used as the initial excitation port, which is used to receive an initial excitation optical signal with a pulse width of Δt. In some embodiments, an initial excitation source 8 can be provided to apply an initial excitation optical signal with a pulse width of Δt to the initial excitation port. The initial excitation source 8 can be located at any position of the first optical path 32 or any position of the second optical path 31, as long as an initial excitation optical signal with a pulse width of Δt is applied to the optical path.

[0053] In this invention, the optical input terminal of the optical path control module is used to receive monochromatic light of a fixed wavelength. In some embodiments, a monochromatic laser can be provided to apply monochromatic light of a fixed wavelength to the optical input terminal of the optical path control module.

[0054] Example 2

[0055] like Figure 6 The diagram shown is a schematic of the PRBS pseudo-random code generator in Example 2.

[0056] In this embodiment, the PRBS pseudo-random code generator includes a first optical path, a beam splitter, a first delay line, a second delay line, a beam combiner, a second optical path, and an optical path control module. The functions of each component are the same as in Embodiment 1, and can be found in the description of Embodiment 1. They will not be repeated here.

[0057] The main difference between Example 2 and Example 1 lies in the design of the optical path control module. The following will primarily focus on the optical path control module used in this example.

[0058] In this embodiment, the optical path control module includes a photodiode, a transimpedance amplifier, and a Mach-Zehnder interferometer (MZI). The photodiode converts the optical signal output from the second optical path into a current signal. The transimpedance amplifier converts the current signal into an amplified voltage signal, which serves as the control signal for the Mach-Zehnder interferometer. One of any two input ports of the Mach-Zehnder interferometer serves as the optical input port of the optical path control module, receiving monochromatic light. One of any two output ports of the Mach-Zehnder interferometer serves as the optical output port of the optical path control module. Different control voltages received at the control port of the Mach-Zehnder interferometer result in different control power, such as... Figure 7The graph shows the transmittance at the output of a Mach-Zehnder interferometer as a function of power. As can be seen, for a fixed wavelength monochromatic light input to the Mach-Zehnder interferometer, when the applied power is controlled at P1, the transmittance at the output is at its peak, indicating light output at the input. However, when the applied power is too high or too low, the transmittance is very low, and there is virtually no light output at the input. Utilizing this characteristic, when only one of the first delay line 10 and the second delay line 11 has an optical signal output at the same time, this optical signal can be converted into a voltage V. λ The power P1 corresponds to the peak transmittance of the download end, resulting in light output. The operational logic is: when the input is 01 or 10, the output is 1. When neither the first delay line 10 nor the second delay line 11 outputs light, the power corresponding to the converted light signal is less than P1, resulting in low transmittance and almost no light output at the download end. The operational logic is: when the input is 00, the output is 0. When both the first delay line 10 and the second delay line 11 output light, the power corresponding to the converted light signal is greater than P1, resulting in low transmittance and almost no light output at the download end. The operational logic is: when the input is 11, the output is 0. Therefore, based on the design of the above optical path control module and delay lines, a specific bit XOR operation can be implemented to generate a PRBS pseudo-random code.

[0059] In this embodiment, an initial excitation source with a pulse width of one symbol is added in front of the photodiode. This excitation source is bundled into the optical fiber using a Y-type bundler. Only one initial excitation pulse needs to be input, which is equivalent to inputting 1 after k-1 consecutive 0 symbols. This realizes the initial input of a group of k symbols in one cycle of the PRBS k-order code pattern. Subsequent code streams will be automatically generated and continuously cycled.

[0060] Example 3

[0061] like Figure 8 The diagram shown is a schematic of the PRBS pseudo-random code generator in Example 3.

[0062] In this embodiment, the PRBS pseudo-random code generator includes a first optical path, a beam splitter, a first delay line, a second delay line, a beam combiner, a second optical path, and an optical path control module. The functions of each component are the same as in Embodiment 1, and can be found in the description of Embodiment 1. They will not be repeated here.

[0063] The main difference between Example 3 and Example 1 lies in the design of the optical path control module. The following will primarily focus on the optical path control module used in this example.

[0064] In this embodiment, the optical path control module includes a π phase shifter and an all-optical switch. The π phase shifter is located at the output end of the first delay line or the second delay line. The control end of the all-optical switch serves as the control end of the optical path control module. The input end of the all-optical switch serves as the optical input end of the optical path control module to receive monochromatic light. The output end of the all-optical switch serves as the optical output end of the optical path control module.

[0065] In this embodiment, a π phase shifter is added to any delay line. No light intensity is denoted as 0, and light intensity is denoted as 1. When the two XOR bits are 00, meaning there is no light intensity, the beam combiner has no light intensity output, the optical switch remains closed, and the output is 0. When the two XOR bits are 01 or 10, the beam combiner has light intensity output, opening the optical switch and outputting 1. When the two XOR bits are 11, ... Figure 9 The π phase shifter causes the two beams to coherently cancel each other out, the beam combiner has no light intensity output, the optical switch remains closed, and the output is 0.

[0066] In this embodiment, the initial excitation source with a pulse width of one symbol length is bundled into the optical fiber using a Y-type combiner. Only one initial excitation pulse is required, which is equivalent to inputting a 1 after k-1 consecutive 0 symbols. This achieves the initial input of a group of k symbols in one cycle of the PRBS k-order code pattern. Subsequent code streams are automatically generated and continuously cycled. Using an all-optical switch avoids the response time of electro-optical devices and greatly reduces energy consumption. For example, a cavity-less all-optical switch using the strong transient second-order nonlinearity of lithium niobate nanowaveguides can achieve a switching speed of up to 46 fs with an energy consumption of only 80 fJ. Alternatively, a deep subwavelength plasmonic waveguide loaded with nonlinear absorbing graphene or other high-speed, low-energy all-optical switches can be used instead.

[0067] In summary, the PRBS pseudo-random code generator proposed in this invention employs optical transmission delay, which can adapt to different PRBS digit types and code stream rates. Only the delay line length needs to be adjusted without increasing the number of additional optical components, enabling the generation of long-cycle PRBS codes. Furthermore, the total computational speed of the aforementioned PRBS pseudo-random code generator is only limited by the time constant of carrier diffusion in the optoelectronic device, theoretically reaching speeds of 40 Gbit / s or even higher, significantly improving computational speed compared to traditional methods using feedback shift registers and XOR gates.

[0068] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered to be within the scope of this specification. It should be noted that the terms "in one embodiment," "for example," and "as in another example" in this application are intended to illustrate the application and are not intended to limit the application.

[0069] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An optically based PRBS pseudo-random code generator, characterized in that, It includes a first optical path, a beam splitter, a first delay line, a second delay line, a beam combiner, a second optical path, and an optical path control module. The optical path control module includes an optical input terminal, an optical output terminal, and a control terminal. The beam splitter is used to split the light from the first optical path into two beams, which then enter the beam combiner via the first delay line and the second delay line, respectively. The combined light output from the beam combiner enters the control terminal of the optical path control module via the second optical path. The optical input terminal of the optical path control module is used to receive monochromatic light of a fixed wavelength. The optical output terminal is controlled by the control terminal. When the first delay line and the second delay line have optical signal output at the same time or have no optical signal output at the same time, the control terminal controls the optical output terminal to have no optical signal output. When the first delay line and the second delay line have optical signal output on only one of them at the same time, the control terminal controls the optical output terminal to output the monochromatic light and enter the first optical path. The delay of the first delay line is τ1, and the delay of the second delay line is τ2, where τ2-τ1=m*Δt, and m is the number of bits that differ between the two symbols in the XOR calculation performed in the PRBS pseudo-random code generator, and the symbol width is... r is the order of the PRBS pseudo-random code, τ delay1 The time taken for the optical signal to return to the starting point of the first optical path after passing through the first optical path, beam splitter, first delay line, beam combiner, second optical path and optical path control module; An initial excitation port is set at any position of the first or second optical path, and the initial excitation port is used to receive an initial excitation optical signal with a pulse width of Δt. Using any position on the first optical path as the output terminal of the PRBS pseudo-random code generator, when there is an optical signal at the output terminal, it indicates that the data is "1", and when there is no optical signal at the output terminal, it indicates that the data is "0".

2. The optical-based PRBS pseudo-random code generator according to claim 1, characterized in that, The optical path control module includes a photodiode, a transimpedance amplifier, and a microring resonator. The photodiode is used to convert the optical signal output from the second optical path into a current signal. The transimpedance amplifier is used to convert the current signal into an amplified voltage signal and use it as a control signal for the microring resonator. The input terminal of the microring resonator serves as the optical input terminal of the optical path control module to receive the monochromatic light, and the output terminal of the microring resonator serves as the optical output terminal of the optical path control module.

3. The optical-based PRBS pseudo-random code generator according to claim 1, characterized in that, The optical path control module includes a photodiode, a transimpedance amplifier, and a Mach-Zehnder interferometer. The photodiode is used to convert the optical signal output from the second optical path into a current signal. The transimpedance amplifier is used to convert the current signal into an amplified voltage signal and use it as a control signal for the Mach-Zehnder interferometer. One of any two input ports of the Mach-Zehnder interferometer serves as the optical input terminal of the optical path control module to receive the monochromatic light, and one of any two output ports of the Mach-Zehnder interferometer serves as the optical output terminal of the optical path control module.

4. The optical-based PRBS pseudo-random code generator according to claim 1, characterized in that, The optical path control module includes a π phase shifter and an all-optical switch. The π phase shifter is located at the output end of the first delay line or the second delay line. The control end of the all-optical switch serves as the control end of the optical path control module. The input end of the all-optical switch serves as the optical input end of the optical path control module to receive the monochromatic light. The output end of the all-optical switch serves as the optical output end of the optical path control module.

5. The optical-based PRBS pseudo-random code generator according to claim 1, characterized in that, The beam combiner is a Y-type beam combiner, a directional coupler, or a multimode interferometer with optical beam combining function.

6. The optical-based PRBS pseudo-random code generator according to claim 1, characterized in that, The beam splitter is a Y-type beam splitter with optical beam splitting function, or a directional coupler or a multimode interferometer.

7. The optical-based PRBS pseudo-random code generator according to claim 1, characterized in that, A beam splitter is also provided on the first optical path. The beam splitter is used to split a beam from the first optical path as the output of the PRBS pseudo-random code generator.

8. The optical-based PRBS pseudo-random code generator according to claim 7, characterized in that, The beam splitter is a 2:8 type beam splitter.

9. The optical-based PRBS pseudo-random code generator according to claim 1, characterized in that, It also includes an initial excitation source for applying an initial excitation optical signal with a pulse width of Δt to the initial excitation port.

10. The optical-based PRBS pseudo-random code generator according to claim 1, characterized in that, It also includes a monochromatic laser for applying monochromatic light of a fixed wavelength to the optical input terminal of the optical path control module.

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