All-optical nonlinear activator and transmission and calculation integrated implementation method thereof

Abstract

The invention discloses an all-optical nonlinear activator and a transmission and calculation integrated implementation method thereof, and relates to the technical field of optical nonlinearity. The problem that an existing optical neural network lacks an all-optical nonlinear activator which is good in performance and capable of achieving signal cascading is solved. The activator provided by the invention comprises an isolator connected with an input signal, a gain medium connected with the isolator, a pumping signal source and a circulator, wherein the circulator is provided with a first port connected with the pumping signal source, a second port connected with the gain medium and a third port for signal output. The invention further provides a transmission and calculation integrated implementation method and application of the transmission and calculation integrated implementation method in the optical neural network. Under the driving of the pumping signal source, an incident signal is obviously enhanced by a Brillouin scattering effect generated in the gain medium, and an obvious nonlinear amplification effect is realized. And the gain medium also has a signal transmission effect, so that signal transmission and calculation integration is realized in a single platform.

Description

Technical Field

[0001] The present invention relates to the field of optical nonlinear technology, and in particular to an all-optical nonlinear activator and a method for realizing the same. Background Art

[0002] Optical fiber, with its wide bandwidth, low loss, anti-interference, and lightweight properties, has become the core transmission medium for optical communication systems. However, as transmission distances increase, power fading due to dispersion effects becomes increasingly prominent, manifesting as increased system bit error rates, limited transmission distances, and decreased channel capacity. In ultra-long-distance and ultra-high-speed transmission systems, dispersion control becomes a key factor in determining system performance. To this end, researchers have proposed compensation schemes such as dispersion-compensating fiber, fiber Bragg gratings, pre-chirp technology, and digital signal processing to mitigate power fading. However, these schemes all face the multi-objective optimization problem of compensating efficiency, system complexity, and cost during implementation.

[0003] In addition to transmission limitations, optical communication systems also face challenges related to diverse applications and supply-demand imbalances. Driven by massive amounts of data and a rich variety of application scenarios, existing computing approaches, limited by the physical constraints of transistors, face barriers in computing power, cost, memory, and energy consumption, making it difficult to support real-time processing of massive amounts of data. There is an urgent need to explore new computing paradigms and hardware alternative platforms to achieve improvements in computing speed, energy efficiency, and data throughput.

[0004] Analog optical computing architectures, represented by optical neural networks, fully leverage the advantages of optics such as high parallelism, low power consumption, and high bandwidth, and are considered one of the most promising solutions to break through existing computing bottlenecks. Currently, optical neural networks primarily use a hybrid computing architecture, where the implementation of their computing functions relies on traditional microelectronic units (responsible for nonlinear and storage-type calculations and tasks) and optical computing units (responsible for linear computing tasks). Considering limitations such as photoelectric rate mismatch, signal latency, and additional energy consumption, this architecture fails to fully exploit the computing advantages of optical neural networks. The key lies in the lack of scalable all-optical nonlinear activation devices.

[0005] Optical fiber is a typical inhomogeneous transmission medium. When light propagates through it, the inhomogeneous density of the medium causes some photons to deviate from the intended transmission direction, resulting in scattering. Brillouin scattering is a typical nonlinear scattering phenomenon in gain media. It offers advantages such as narrow linewidth, high gain, strong nonlinearity, low threshold, and nanometer-scale relaxation time. These properties give Brillouin scattering great potential for application in the field of optical nonlinearity.

[0006] However, in existing technologies, the Brillouin scattering effect is mainly used in optical filtering, signal generation, and optical sensing. For the time being, there are more applications in optical neural networks that remain to be explored.

[0007] It can be seen that the existing optical neural networks have the obvious defect of lacking all-optical nonlinear activators with good performance and capable of signal cascading. Summary of the Invention

[0008] The purpose of the present invention is to address the aforementioned problem of the lack of high-performance all-optical nonlinear activators capable of signal cascading in existing optical neural networks. The present invention provides an all-optical nonlinear activator and a method for implementing it in a combined transmission and computational framework. The present invention utilizes the dynamics of Brillouin scattering energy transfer to significantly enhance the nonlinear response of the device, thereby achieving nonlinear amplification between input and output power pairs. Based on this, the present invention employs the following technical solutions:

[0009] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions:

[0010] In a first aspect, the present invention provides an all-optical nonlinear activator, comprising an isolator connected to an external input signal, a gain medium connected to the isolator, a pump signal source, and a circulator, wherein the circulator is provided with a first port connected to the pump signal source, a second port connected to the gain medium, and a third port for outputting a signal.

[0011] Furthermore, the pump signal source is used to output a pump signal to the circulator to excite the gain medium and stimulate nonlinear behavior.

[0012] Furthermore, the isolator is used to control the unidirectional transmission of the external input signal to the gain medium.

[0013] Furthermore, the gain medium provides a medium for nonlinear excitation of the pump signal and the external input signal.

[0014] Furthermore, the circulator is used to receive a pump signal and transmit it to the gain medium, and to receive and output a signal output by the gain medium.

[0015] Furthermore, the pump signal source is a high-stability narrow-linewidth light source.

[0016] Furthermore, the gain medium is an optical fiber medium with sufficient nonlinear coefficient.

[0017] In a second aspect, the present invention further provides a method for implementing the transmission-computation integration based on the above-mentioned all-optical nonlinear activator, comprising the following steps:

[0018] Turn on the activator, provide an external input signal and transmit it to the gain medium through the isolator, transmit the pump signal to the circulator and then to the gain medium;

[0019] The external input signal and the pump signal undergo Brillouin scattering in the gain medium to obtain a scattered signal, which is then transmitted to a circulator, and the output signal is output using the circulator, completing the integrated transmission and calculation.

[0020] Furthermore, the integrated transmission and calculation method includes nonlinear amplification, transmission and calculation of the external input signal and the pump signal.

[0021] In a third aspect, the present invention further provides an application of the aforementioned integrated transmission and computation method in an optical neural network. The method can be applied to the nonlinear amplification, transmission, and computation of optical signals. Compared with the prior art, the advantages of the present invention are:

[0022] 1. The present invention provides an all-optical nonlinear activator, comprising an isolator connected to an external input signal, a gain medium connected to the isolator, a pump signal source, and a circulator with three ports. The pump signal source is used to output a pump signal to the circulator to excite the gain medium and stimulate nonlinear behavior. The isolator is used to control the unidirectional transmission of the external input signal to the gain medium. The gain medium provides a medium for the nonlinear excitation of the pump signal and the external input signal. The circulator is used to receive the pump signal and transmit it to the gain medium, receive the signal output by the gain medium and output it, controlling the transmission direction of the pump signal and the external input signal. The circulator allows the pump signal to enter the circulator through the first port and then exit the circulator through the second port into the gain medium to stimulate Brillouin scattering. The external input signal enters the gain medium from the isolator, undergoes the required nonlinear amplification, and then enters the circulator through the second port, where it is output from the third port. In this process, the dynamic behavior of Brillouin scattering energy transfer is effectively utilized to significantly enhance the nonlinear response of the device, thereby achieving nonlinear amplification between input and output power.

[0023] Furthermore, the all-optical nonlinear activator of the present invention exhibits a significant nonlinear response, and its nonlinear response process does not involve photoelectric conversion, thereby fully leveraging the advantages of optics to support the implementation of all-optical neural networks. It also exhibits high stability and fast response speed. By providing a well-designed activator structure, the present invention addresses the lack of high-performance all-optical nonlinear activators capable of signal cascading in existing optical neural networks.

[0024] To further elaborate, the all-optical nonlinear activator of the present invention cleverly utilizes the dual properties of optical fiber as a nonlinear medium and a transmission medium, realizing collaborative processing that integrates signal transmission and computing in the same optical path.

[0025] Further elaboration reveals that the all-optical nonlinear activator of this invention overcomes the bottlenecks of traditional nonlinear devices in terms of transmission efficiency, activation threshold, and operating bandwidth. Its efficient nonlinear amplification creates the necessary conditions for multi-layer network cascading, enabling parallel processing of multi-wavelength signals based on wavelength division multiplexing technology. This not only fully exploits the advantages of optical multi-degrees of freedom but also provides a new technical path for the structural design and application expansion of all-optical neural networks, with enormous potential for application.

[0026] 2. The invention provides a method for realizing the transmission and calculation integration of an all-optical nonlinear activator. The method is simple to realize, easy to operate, and has a wide range of applications.

[0027] To further elaborate, the transmission and calculation integrated implementation method of the present invention does not involve any electrical signal processing in the entire calculation process, builds a complete end-to-end nonlinear mapping system, and provides core device support for the all-optical neural network architecture.

[0028] 3. The application of the integrated transmission and calculation method provided by the present invention in optical neural networks is repeatable and has great application space and potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the structure of the all-optical nonlinear activator 1 according to embodiment 1 of the present invention.

[0030] Figure 2 Schematic diagram of the transmission characteristics of the all-optical nonlinear activator 1 according to Example 1 of the present invention.

[0031] Figure 3 Schematic diagram of the dynamically reconfigurable configuration of the amplification performance of the all-optical nonlinear activator 1 according to embodiment 1 of the present invention.

[0032] Figure 4 This is a schematic structural diagram of the wavelength division multiplexing structure of embodiment 2 of the present invention.

[0033] in, Figure 2 (a) is the nonlinear amplification curve; (b) is the output nonlinear curve.

[0034] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0035] Therefore, the detailed description of the embodiments of the present invention provided below is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention. DETAILED DESCRIPTION

[0036] In a first aspect, the present invention provides an all-optical nonlinear activator, comprising an isolator connected to an external input signal, a gain medium connected to the isolator, a pump signal source, and a circulator, wherein the circulator is provided with a first port connected to the pump signal source, a second port connected to the gain medium, and a third port for outputting a signal.

[0037] It can be understood that the device comprises an isolator connected to an external input signal, a gain medium connected to the isolator, a pump signal source, and a circulator with three ports. The pump signal source outputs a pump signal to the circulator, stimulating the gain medium and stimulating nonlinear behavior. The isolator controls the unidirectional transmission of the external input signal to the gain medium. The gain medium provides a medium for the nonlinear excitation of the pump signal and the external input signal. The circulator receives the pump signal and transmits it to the gain medium, receives the signal output by the gain medium and outputs it, controlling the transmission direction of the pump signal and the external input signal. The circulator allows the pump signal to enter the circulator through the first port and exit the circulator through the second port, entering the gain medium to stimulate Brillouin scattering. The external input signal enters the gain medium from the isolator, undergoes the required nonlinear amplification, and then enters the circulator through the second port, where it is output from the third port. This process effectively utilizes the dynamic behavior of Brillouin scattering energy transfer to significantly enhance the nonlinear response of the device, thereby achieving nonlinear amplification between input and output power.

[0038] The nonlinear enhancement mechanism for achieving nonlinear amplification between the input and output power pairs is further explained: Brillouin scattering describes the energy exchange between light and acoustic phonons. It is an inelastic scattering phenomenon induced by thermally excited acoustic waves in a nonlinear medium, and the entire scattering process obeys the laws of conservation of energy and momentum. Physically, Brillouin scattering can be described as a nonlinear process in which pump waves and Stokes waves interact through acoustic waves. Under small-signal injection conditions, spontaneous scattering dominates, and the thermally excited motion of the medium causes a periodic modulation of the material's refractive index, generating Stokes waves proportional to the incident intensity. As the incident light intensity increases, spontaneous scattering transitions to stimulated scattering. In this state, the strong interaction between light and the nonlinear medium generates a mutual gain between the acoustic wave and the scattered light wave through the electrostrictive effect. This enhancement creates a positive feedback mechanism, resulting in exponential gain in the scattered light, thereby achieving efficient energy conversion from incident light to backscattered light.

[0039] It should be noted that the external input signal is a conventional means in the prior art, that is, an input signal transmitted or connected externally. The detection signal is an optical signal.

[0040] In some embodiments of the present invention, the pump signal source is used to output a pump signal to the circulator to excite the gain medium and stimulate nonlinear behavior.

[0041] In some embodiments of the present invention, the isolator is used to control the unidirectional transmission of the external input signal to the gain medium.

[0042] In some embodiments of the present invention, the gain medium provides a medium for nonlinear excitation of a pump signal or an external input signal.

[0043] In some embodiments of the present invention, the circulator is configured to receive a pump signal and transmit it to a gain medium, and to receive and output a signal output by the gain medium.

[0044] In some embodiments of the present invention, the circulator is preferably an optical circulator.

[0045] In some embodiments of the present invention, the pump signal source is a high-stability narrow-linewidth light source.

[0046] In some embodiments of the present invention, the gain medium is an optical fiber medium having a sufficient nonlinear coefficient.

[0047] In a second aspect, the present invention further provides a method for implementing the transmission-computation integration based on the above-mentioned all-optical nonlinear activator, comprising the following steps:

[0048] Turn on the activator, provide an external input signal and transmit it to the gain medium through the isolator, transmit the pump signal to the circulator and then to the gain medium;

[0049] The external input signal and the pump signal undergo Brillouin scattering in the gain medium to obtain a scattered signal, which is then transmitted to a circulator, and the output signal is output using the circulator, completing the integrated transmission and calculation.

[0050] In some embodiments of the present invention, the output signal is an optical signal.

[0051] In some embodiments of the present invention, the integrated transmission and calculation method includes nonlinear amplification, transmission, and calculation of the external input signal and the pump signal.

[0052] It is understood that in the present invention's integrated transmission and computation method, the activator uses a gain medium as a nonlinear medium. When an external input signal (optical signal) is transmitted through the medium, the light-acoustic energy transfer behavior during Brillouin scattering is precisely controlled to achieve significant nonlinear gain, thereby completing the nonlinear transformation required for optical computation.

[0053] Furthermore, the ultra-long gain medium incorporated into the activator not only enhances the efficiency of nonlinear interactions, but its inherent optical properties also ensure efficient signal transmission. This unique physical mechanism enables the device to simultaneously achieve the dual functions of computation and transmission within a single structure, providing key technical support for the construction of all-optical nonlinear activation devices that integrate computation and transmission.

[0054] The entire computational process does not involve any electrical signal processing, building a complete end-to-end nonlinear mapping system and providing core device support for the all-optical neural network architecture. The implementation method is simple, easy to operate, and has a wide range of applications.

[0055] Thirdly, the present invention also provides an application of the aforementioned integrated transmission and computation method in optical neural networks. This method can be applied to the nonlinear amplification, transmission, and computation of optical signals. It is repeatable and has significant potential for application.

[0056] Example 1

[0057] In this embodiment, an all-optical nonlinear activator 1 is provided. Figure 1 , including an isolator connected to an external input signal, a gain medium connected to the isolator, a pump signal source, and a circulator (optical circulator), wherein the optical circulator is provided with a first port (port 1) connected to the pump signal source, a second port (port 2) connected to the gain medium, and a third port (port 3) for outputting a signal.

[0058] Please continue to refer to Figure 1 The pump signal source is used to output a pump signal to the optical circulator to excite the gain medium and stimulate nonlinear behavior. The isolator is used to control the unidirectional transmission of the external input signal to the gain medium. The gain medium provides a medium for the nonlinear excitation of the pump signal and the external input signal. The circulator is used to receive the pump signal and transmit it to the gain medium, and receive and output the signal output by the gain medium.

[0059] Example 2

[0060] In this embodiment, a wavelength division multiplexing structure is constructed based on an all-optical nonlinear activator 1 obtained in Example 1. For its specific structure, please refer to Figure 4 .

[0061] Wavelength division multiplexing structure is crucial to fully utilize the advantages of optical multi-degree of freedom. Figure 4 In this embodiment, a wavelength division multiplexing structure is constructed:

[0062] The optical circulator includes an isolator connected to an external input signal, a gain medium (fiber medium) connected to the isolator, a pump signal source, an optical circulator, and an optical coupler connected to the input end of the isolator. The optical circulator is provided with port 1, port 2, and port 3.

[0063] The external input signal includes multiple signal sources: signal source 1, signal source 2, ..., signal source N. Signal source 1, signal source 2, ..., signal source N are all connected to the input end of the optocoupler. The output end of the optocoupler is connected to the input end of the isolator.

[0064] The optical fiber medium is connected to port 2 of the optical circulator.

[0065] The pump signal source includes an optical coupler connected to port 1 and a plurality of pump sources connected to the input end of the optical coupler: pump source 1, pump source 2, ..., pump source N.

[0066] Set up signal source 1, signal source 2, ..., signal source N; and configure multi-wavelength pump sources that match the number of input signals: pump source 1, pump source 2, ..., pump source N. By precisely controlling the wavelength of each signal source, it matches the Brillouin frequency shift of the corresponding pump source.

[0067] Port 3 of the optical circulator is connected to the input of the wavelength division multiplexer, and the output of the wavelength division multiplexer is connected to output signals of multiple wavelengths: wavelength 1, wavelength 2, ... wavelength N. At the output end, the wavelength division multiplexer is used to efficiently demultiplex the multiplexed signals after nonlinear processing.

[0068] As can be seen, the wavelength division multiplexing structure in this embodiment utilizes multiple different pump sources. These pump sources are coupled together through a coupler and then injected into the gain medium (fiber medium) via a circulator (optical circulator). During this process, the different pump sources generate Stokes waves with the same Brillouin frequency shift, but with a relatively downshifted frequency. Because these Stokes waves match the wavelength of the corresponding input signal source, the energy transfer mechanism of the pump signal described above ultimately achieves effective amplification of the input signal. Finally, a wavelength division multiplexer is used to separate the signals of different wavelengths.

[0069] In summary, the wavelength division multiplexing structure in this embodiment can realize parallel nonlinear amplification of multi-channel signals, give full play to the advantages of optical neural networks in multi-degree-of-freedom processing, and has excellent performance.

[0070] Test Example 1 Performance Verification

[0071] 1.1 Experimental design

[0072] In this experimental example, the effect of the all-optical nonlinear activator 1 obtained in Example 1 was verified.

[0073] The specific test settings are as follows:

[0074] 1.11 Test 1

[0075] The all-optical nonlinear activator 1 obtained in Example 1 was selected to measure the transmission characteristics, and the nonlinear amplification curve and the output nonlinear curve were measured respectively. The measurement results are shown in FIG. Figure 2 .

[0076] 1.1.2 Test 2

[0077] The all-optical nonlinear activator 1 obtained in Example 1 was selected to perform a dynamic reconfigurable configuration test on the amplification performance of the nonlinear activator. The test results are shown in FIG. Figure 3 .

[0078] 1.2 Experimental process and result analysis

[0079] Based on the physical mechanism and hardware architecture of the developed all-optical nonlinear activation device, the experimental example of this invention successfully constructed an experimentally verified nonlinear activation function for an optical neural network. Furthermore, by precisely controlling the incident light power, directional excitation of Brillouin scattering in a nonlinear medium can be achieved, thereby obtaining a Stokes wave output with significant nonlinear characteristics.

[0080] See also Figure 2 (a) shows the nonlinear amplification curve of Brillouin scattering. Clearly, when the incident light power falls below a certain threshold, the device transmission efficiency drops sharply, while remaining constant at higher powers, exhibiting a clear saturation amplification phenomenon.

[0081] By multiplying the above transmission characteristics with the input power, an input-output power mapping relationship model can be established, thereby realizing the optical domain nonlinear transformation function.

[0082] Please continue to refer to Figure 2 (b) Due to the need to quantify the performance of the device, the experimental data is not normalized. At the same time, in order to achieve effective amplification, the wavelength of the signal source needs to be adjusted to match the Brillouin frequency shift of the pump source.

[0083] Transmission efficiency is key to developing practical nonlinear activators. Conventional devices are limited by the cumulative effect of power loss, making it difficult to meet the cascading requirements of multi-layer neural network architectures. The all-optical nonlinear activator developed in this paper offers two advantages: first, it significantly improves the device's energy transmission efficiency through the Brillouin scattering mechanism; second, it leverages the device's intrinsic amplification properties to achieve a sensitive response to small signals, overcoming the power limitations of conventional devices.

[0084] Please continue to see Figure 3 Experimental results show that as the pump power gradually increases, the gain characteristics and saturation threshold of the nonlinear activator both show an upward trend, and the saturation amplification behavior is stable under different excitation powers. This characteristic demonstrates that a single pump source can drive multiple nonlinear dielectric units in parallel, which not only effectively improves system resource utilization but also provides a feasible solution for building large-scale parallel optical neural networks.

[0085] Transmission bandwidth is a key metric for achieving high data throughput. Unlike traditional Brillouin schemes, the nonlinear activator developed in this paper operates independently from the pump and signal sources. This decoupled configuration of the pump and signal optical paths effectively eliminates the inherent constraints imposed by the Brillouin frequency shift (approximately 10 GHz) on the signal modulation bandwidth. In this configuration, the bandwidth of the modulated signal that can be loaded onto the signal source is theoretically unlimited, providing key technical support for fully realizing the potential of optical computing for high-throughput data processing.

[0086] In summary, based on the transmission characteristic measurements and the dynamic reconfigurable configuration measurements of the amplification performance of the all-optical nonlinear activator 1 in the experimental examples, it was found that the all-optical nonlinear activator 1 prepared in Example 1 can achieve directional excitation of Brillouin scattering in nonlinear media, has a Stokes wave output with significant nonlinear characteristics, and has good transmission characteristics. Therefore, it has a wide range of applications and has strong advantages. The above example is only one embodiment of the present invention, and its description is relatively specific and detailed, but it should not be understood as limiting the scope of the patent of the present invention. It should be pointed out that for those skilled in the art, several variations and improvements can be made without departing from the concept of the present invention, and these are all within the scope of protection of the present invention. Therefore, the scope of protection of the patent of the present invention should be based on the appended claims.

Claims

1. An all-optical nonlinear activator, characterized in that: The invention comprises an isolator connected to an external input signal, a gain medium connected to the isolator, a pump signal source, and a circulator. The circulator is provided with a first port connected to the pump signal source, a second port connected to the gain medium, and a third port for outputting a signal.

2. The all-optical nonlinear activator according to claim 1, characterized in that: The pump signal source is used to output a pump signal to the circulator to excite the gain medium and stimulate nonlinear behavior.

3. The all-optical nonlinear activator according to claim 2, characterized in that: The isolator is used to control the unidirectional transmission of the external input signal to the gain medium.

4. The all-optical nonlinear activator according to claim 3, characterized in that: The gain medium provides a medium for nonlinear excitation of a pump signal and an external input signal.

5. The all-optical nonlinear activator according to claim 4, characterized in that: The circulator is used to receive a pump signal and transmit it to a gain medium, and to receive and output a signal output by the gain medium.

6. The all-optical nonlinear activator according to claim 1, characterized in that: The pump signal source is a high-stability narrow-linewidth light source.

7. The all-optical nonlinear activator according to claim 1, characterized in that: The gain medium is an optical fiber medium with sufficient nonlinear coefficient.

8. A method for realizing transmission and calculation integration of an all-optical nonlinear activator according to any one of claims 1 to 7, characterized in that: The following steps are involved: Turn on the activator, provide an external input signal and transmit it to the gain medium through the isolator, transmit the pump signal to the circulator and then to the gain medium; The external input signal and the pump signal undergo Brillouin scattering in the gain medium to obtain a scattered signal, which is then transmitted to a circulator, and the output signal is output using the circulator, completing the integrated transmission and calculation.

9. The method for realizing integrated transmission and calculation according to claim 8, characterized in that: The integrated transmission and calculation includes nonlinear amplification, transmission and calculation of the external input signal and the pump signal.

10. An application of the transmission-calculation integration method according to claim 8 or 9 in an optical neural network, characterized in that: The implementation method can be applied to nonlinear amplification, transmission and calculation of optical signals.

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