An optical Ising model calculation method and system based on wavelength division multiplexing

Abstract

The application discloses an optical Ising model calculation method and system based on wavelength division multiplexing. The application can load any Ising model, greatly increases the adaptability of the system, has the advantages of wide application range, fast information transmission, simple structure, low cost, fast calculation and the like. The application takes a coherent multi-wavelength light source as a signal input, splits the light field by using a light splitting device, then encodes the spin, interaction and magnetic field parameters on the light signals of different wavelengths by using an optical modulator, performs optical Fourier transform by using a lens system, makes the light fields of the same wavelength interfere, and combines the light fields of different wavelengths, finally measures the total light intensity after combination by using a detector, so that the Hamiltonian of the Ising model of optical calculation of any interaction is realized. The method provided by the application has important application prospects in solving optimization problems and Ising model phase transition research and the like, and is convenient to integrate in optical chips and the like specific applications.

Description

Technical Field

[0001] This invention relates to the fields of optical computing and optical information processing, and in particular to a calculation method and system for the optical Ising model based on wavelength division multiplexing. Background Technology

[0002] Currently, most computation and data transmission are handled by electronic chips. However, traditional electronic chips can no longer meet the needs of neural network algorithms because they involve a large number of matrix calculations, which greatly reduces computational efficiency. Only by increasing the integration density of microelectronics can the problem of slow computation be solved. However, following Moore's Law, the disadvantages of increasing circuit integration have also become apparent: increased power consumption and higher production costs. Optical computing can solve these problems by using photons to achieve ultra-high-speed, low-energy computation. Different wavelengths of light can carry different information, enabling wavelength division multiplexing; stable transmission is also possible under high-frequency modulation; furthermore, optical transmission offers excellent security and is unaffected by magnetic field interference; Fourier transforms are performed at the speed of light, greatly increasing the speed of two-dimensional matrix operations. Therefore, optical computing provides a new approach for complex and rapid computation.

[0003] In recent years, numerous Ising machines have emerged that simulate the Ising model to solve nondeterministic polynomial (NP) combinatorial optimization problems. These include Ising machines based on various principles such as optical parametric amplifiers, superconducting qubits, nanophotonic circuits, and spatial optical modulation. These NP problems include the Traveling Salesman Problem, graph coloring problem, complete subgraph problem, and maximum cut problem. In Ising machines, the optimal solution to these problems is obtained by solving the ground state of the Ising model. The Ising model is a classical problem in physics, consisting of multiple spins, and its Hamiltonian can be written as... J jk For the interaction between any two spins, σ i =±1 indicates spin-up and spin-down, h i For magnetic field parameters. The Hamiltonian of the Ising model can be rewritten as constraints for many NP problems. Therefore, calculating the minimum or maximum value of the Hamiltonian is equivalent to finding the optimal solution to the problem, and solving these problems will provide solutions to some difficult problems in life and technology.

[0004] However, current systems based on spatial optical modulators cannot simulate the Hamiltonian of arbitrary models, and their information transmission capacity and system adaptability are relatively low. The wavelength division multiplexing (WDM) technology proposed in this invention can simultaneously load multiple pieces of information onto different wavelengths of a single beam, increasing the information transmission capacity and improving the matrix operation speed. Furthermore, based on WDM, this system can simulate any Ising model, including Ising models with other parameters, providing a new method for solving combinatorial optimization problems. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a wavelength division multiplexing-based optical Ising model calculation method and system, capable of loading and calculating arbitrary Ising models. The method proposed in this invention modulates different information onto different wavelengths, significantly improving calculation speed. It also boasts advantages such as wide applicability, fast information transmission, simple structure, and low cost. Because it can simulate arbitrary Ising models, it greatly increases the system's adaptability. The system proposed in this invention comprises a beam splitting system, a signal modulation system, a lens system, and an intensity detection system connected in sequence. This is reflected in the fact that the equipment only requires basic optical equipment such as a coherent multi-wavelength light source, beam splitting device, modulator, lens group, and detector. The experimental optical path is simple, and only one modulator is needed, further reducing costs. The device size can be designed on the wavelength scale, facilitating integration into specific applications such as optical chips.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] According to a first aspect of the present invention, a method for calculating the optical Ising model based on wavelength division multiplexing is provided, the method comprising:

[0008] Wavelength dispersion of the emitted light field from a coherent multi-wavelength light source is achieved using a beam splitter.

[0009] The spin, interaction, and magnetic field parameters of the Ising model are encoded onto optical signals of different wavelengths using an optical modulator;

[0010] The encoded optical signal is subjected to optical Fourier transform using a lens system, which interferes light fields with the same wavelength and merges light fields with different wavelengths.

[0011] By measuring the combined total light intensity using a detector, the Hamiltonian of the Ising model with arbitrary interactions can be optically calculated.

[0012] Furthermore, the Ising model is a Hamiltonian. or The Ising model, where N is the number of spins, σ i For spin, J jk For any two spins σ j ,σ k The interaction, h i For spin σ i The corresponding magnetic field parameters.

[0013] Furthermore, the coherent multi-wavelength light source includes, but is not limited to, supercontinuum laser, and the beam splitter includes, but is not limited to, a grating.

[0014] Furthermore, a coherent multi-wavelength light source is obliquely incident onto a beam splitter such as a grating. By utilizing the beam splitting characteristics of the grating, partially coherent light is generated and ordered incident on different positions of the spatial light modulator.

[0015] Furthermore, when all magnetic field parameters of the Ising model are zero, the optical modulator can modulate the optical signal based solely on spin and interaction.

[0016] Furthermore, the optical modulator is a time-space optical modulator, and the modulation method includes, but is not limited to, amplitude or phase modulation.

[0017] Furthermore, to make the system more compact and reduce errors, the spin, interaction, and magnetic field parameters are encoded onto a phase-type optical modulator using gauge transformation.

[0018] Furthermore, an optical modulator is used to encode a spin at multiple locations, while a checkerboard pattern is employed on one spin, the shape of which is consistent with the beam coherence.

[0019] Furthermore, the lens system includes, but is not limited to, ordinary lenses, micro / nano structure lenses, and time lenses.

[0020] Furthermore, the detector includes, but is not limited to, photodetectors and optical cameras.

[0021] Further signal processing is performed, and the intensity at a specific location on the detector is taken as the Hamiltonian. I i The intensity represents different wavelengths.

[0022] According to a second aspect of the present invention, an optical Ising model calculation system based on wavelength division multiplexing is provided, the system comprising a beam splitting system, a signal modulation system, a lens system, and an intensity detection system;

[0023] The beam splitting system uses a coherent multi-wavelength light source as the signal input, and uses a beam splitting device to expand the wavelength before inputting it into a signal modulation system for processing.

[0024] The signal modulation system is used to encode the spin, interaction and magnetic field parameters of the Ising model onto an optical modulator, and to load optical signals by incident different wavelengths onto corresponding positions of the optical modulator.

[0025] The lens system is used to perform optical Fourier transform on the optical signal modulated by the signal modulation system, to interfere optical fields with the same wavelength, and to merge optical fields with different wavelengths.

[0026] The intensity detection system is used to measure the total light intensity output by the lens system, and a certain intensity range of the total light intensity is taken as the Hamiltonian of the Ising model.

[0027] The beneficial effects of this invention are as follows: This invention utilizes wavelength division multiplexing (WDM) technology to increase the efficiency of information transmission and computation, while significantly enhancing the degrees of freedom in simulating the Ising model. This allows the invention to compute any Ising model, and the system can be designed as a subwavelength structure for easy integration onto optical chips. In practical applications, the Ising model computation method proposed in this invention has advantages such as wide applicability, fast information transmission, simple structure, and low cost. Attached Figure Description

[0028] Figure 1 A schematic diagram of the optical Ising model calculation method and system based on wavelength division multiplexing provided by the present invention;

[0029] Figure 2 The optical path diagram is shown in the example.

[0030] Figure 3 A schematic diagram of the gauge transformation of spin, interaction, and magnetic field parameters applied to a space light modulator;

[0031] Figure 4 A schematic diagram illustrating the specific encoding pattern of the chessboard grid during standardization transformation. Detailed Implementation

[0032] The embodiments of the present invention are described in detail below. These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments.

[0033] This invention provides a calculation method for the optical Ising model based on wavelength division multiplexing, the method comprising:

[0034] Wavelength dispersion of the emitted light field from a coherent multi-wavelength light source is achieved using a beam splitter.

[0035] The spin, interaction, and magnetic field parameters of the Ising model are encoded onto optical signals of different wavelengths using an optical modulator;

[0036] The encoded optical signal is subjected to optical Fourier transform using a lens system, which interferes light fields with the same wavelength and merges light fields with different wavelengths.

[0037] By measuring the combined total light intensity using a detector, the Hamiltonian of the Ising model with arbitrary interactions can be optically calculated.

[0038] Furthermore, the Ising model provides a Hamiltonian. or The Ising model, where N is the number of spins, σ i For spin, J jk For any two spins σ j ,σ kThe interaction, h i For spin σ i The corresponding magnetic field parameters.

[0039] like Figure 1 The image shows an embodiment of an optical Ising model computational system based on wavelength division multiplexing, comprising a beam splitting system, a signal modulation system, a lens system, and an intensity detection system connected in sequence.

[0040] The beam splitting system includes a coherent multi-wavelength light source and a beam splitter. The coherent multi-wavelength light source is used as the signal input; after passing through the beam splitter, partially coherent light is generated and sequentially incident on different positions of the spatial light modulator. Furthermore, the optical path uses a coherent multi-wavelength light source, including but not limited to supercontinuum lasers, and the beam splitter includes but is not limited to gratings.

[0041] The signal modulation system includes a computer and a modulator, with the modulator connected to the computer. The spin, interaction, and magnetic field parameters of the Ising model are encoded on a temporal or spatial optical modulator, and optical signals are loaded by incident optical signals at corresponding positions on the modulator at different wavelengths. The modulator includes, but is not limited to, temporal or spatial optical modulators, and the modulation methods include, but are not limited to, amplitude or phase adjustment. When all magnetic field parameters of the Ising model are zero, the modulator can modulate the optical signal based solely on spin and interaction.

[0042] The lens system uses lenses and other devices to perform optical Fourier transform on the optical signal modulated by the signal modulation system, interfering light fields with the same wavelength and merging light fields with different wavelengths. Lenses include, but are not limited to, ordinary lenses, micro / nano structure lenses, and time lenses.

[0043] The intensity detection system uses a detector to receive the combined total light intensity and takes a certain intensity range of the total light intensity as the Hamiltonian of the Ising model. The detector includes, but is not limited to, photodetectors, optical cameras, etc.

[0044] like Figure 2The diagram shows the specific optical path of an embodiment. It includes a supercontinuum laser, lens groups L1 and L2, a grating, a cylindrical lens CL, a polarizer P, a phase-type spatial light modulator, lens L3, and an optical camera. The supercontinuum laser emits collimated light. Due to the small waist of the output light field, it cannot completely cover the spatial light modulator. Therefore, it needs to be expanded by lenses L1 and L2 and obliquely incident on the grating. Because of the grating's beam splitting characteristics, different wavelengths have different exit angles. It then needs to undergo a one-dimensional Fourier transform through the cylindrical lens CL to collimate and image the beam onto the phase-type spatial light modulator. The resulting beam is partially coherent; the vertical direction contains beams of the same wavelength that can interfere, while the horizontal direction, due to different wavelengths, cannot interfere. Polarizer P ensures that the polarization direction of the beam is aligned with the long axis of the phase-type spatial light modulator. Subsequently, spin, interaction, and magnetic field parameters are encoded onto the phase-type spatial light modulator through a gauge transform, thereby altering the intensity and phase distribution of the wavefront. Coherent beams of the same wavelength undergo optical Fourier transform through an L3 spatial lens, while light field intensities of different wavelengths are combined at the focal plane of the lens, and finally the intensity is detected by an optical camera at the focal plane.

[0045] like Figure 3 As shown, the spin configuration, interaction, and magnetic field parameters are encoded onto a phase-type spatial light modulator using gauge transformation. First, the input interaction matrix J can be decomposed into J = PP using Cholesky decomposition or eigenvalue decomposition. T , where matrix elements Let be the element in the i-th column and j-th row of matrix P; then, define Where i = 1, 2, ..., N, such that Add another fixed spin σ N+1 =1. The phase is encoded on the spatial light modulator as For an upward-directed spin, σ = +1; for a downward-directed spin, σ = -1. The phase distribution is encoded onto different wavelengths using a phase-type spatial light modulator, and the phase encoding on the phase-type spatial light modulator varies with time T.

[0046] To further improve experimental accuracy, such as Figure 4 As shown, the present invention uses an optical modulator to encode a spin at multiple locations, while employing a checkerboard pattern on one spin, the shape of which is consistent with the coherence of the light beam.

[0047] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A calculation method for the optical Ising model based on wavelength division multiplexing, characterized in that, include: Wavelength dispersion of the emitted light field from a coherent multi-wavelength light source is achieved using a beam splitter. The spin, interaction, and magnetic field parameters of the Ising model are encoded onto optical signals of different wavelengths using an optical modulator; The encoded optical signal is subjected to optical Fourier transform using a lens system, which interferes light fields with the same wavelength and merges light fields with different wavelengths. By measuring the combined total light intensity using a detector, the Hamiltonian of the Ising model with arbitrary interactions can be optically calculated.

2. The optical Ising model calculation method based on wavelength division multiplexing according to claim 1, characterized in that, The Ising model is a Hamiltonian. or The Ising model, where N is the number of spins, σ i For spin, J jk For any two spins σ j ,σ k The interaction, h i For spin σ i The corresponding magnetic field parameters.

3. The optical Ising model calculation method based on wavelength division multiplexing according to claim 1, characterized in that, The coherent multi-wavelength light source uses multi-wavelength lasers, and the beam splitter uses a grating.

4. The optical Ising model calculation method based on wavelength division multiplexing according to claim 1, characterized in that, When all magnetic field parameters of the Ising model are zero, the optical modulator can modulate the optical signal based solely on spin and interaction.

5. The optical Ising model calculation method based on wavelength division multiplexing according to claim 1, characterized in that, The optical modulator is a time-space optical modulator, and the modulation method is amplitude modulation or phase modulation.

6. The optical Ising model calculation method based on wavelength division multiplexing according to claim 1, characterized in that, Spin, interaction, and magnetic field parameters are encoded onto a phase-type optical modulator using gauge transformation.

7. The optical Ising model calculation method based on wavelength division multiplexing according to claim 1, characterized in that, A spin is encoded at multiple locations using an optical modulator, while a checkerboard pattern is used on one spin, the shape of which is consistent with the beam coherence.

8. The optical Ising model calculation method based on wavelength division multiplexing according to claim 1, characterized in that, The lens system can be a conventional lens, a micro / nano structure lens, or a time lens.

9. The optical Ising model calculation method based on wavelength division multiplexing according to claim 1, characterized in that, The detector is a photodetector or an optical camera.

10. A computational system for the optical Ising model based on wavelength division multiplexing, characterized in that, This includes a beam splitting system, a signal modulation system, a lens system, and an intensity detection system; The beam splitting system uses a coherent multi-wavelength light source as the signal input, and uses a beam splitting device to expand the wavelength before inputting it into a signal modulation system for processing. The signal modulation system is used to encode the spin, interaction and magnetic field parameters of the Ising model onto an optical modulator, and to load optical signals by incident different wavelengths onto corresponding positions of the optical modulator. The lens system is used to perform optical Fourier transform on the optical signal modulated by the signal modulation system, to interfere optical fields with the same wavelength, and to merge optical fields with different wavelengths. The intensity detection system is used to measure the total light intensity output by the lens system, and a certain intensity range of the total light intensity is taken as the Hamiltonian of the Ising model.

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