Reconfigurable photonic crystal device for optical reasoning classification and implementation method thereof

Abstract

The invention provides a reconfigurable photonic crystal device for optical reasoning classification and an implementation method of the reconfigurable photonic crystal device. The reconfigurable photonic crystal device comprises a silicon-on-insulator substrate and photonic crystal units, wherein the photonic crystal units are constructed on the silicon-on-insulator substrate and are formed by first silicon columns which are periodically arranged in two-dimensional square lattices; the photonic crystal unit further comprises a defect structure formed by removing a whole row of first silicon columns in the center of the photonic crystal unit and a tunable defect silicon column which is located in the defect center of the defect structure and is integrated with a micro heater, and at least one second silicon column is distributed on the two sides of the tunable defect silicon column in the lattice direction. According to the reconfigurable photonic crystal device for optical reasoning and classification and the implementation method thereof, the refractive index of the tunable defective silicon column can be dynamically adjusted through the thermo-optic effect, independent regulation and control of optical signals with different wavelengths can be achieved, accurate control of transmitted spectrum and phase response can be achieved, multiple sets of programmable wavelength channels are formed, and the reconfigurable photonic crystal device is suitable for optical reasoning and classification. And on-chip integration of multi-wavelength parallel convolution, all-optical nonlinear activation and diffraction light field modulation can be synchronously realized.

Description

Technical Field

[0001] The present invention relates to the field of integrated photonic computing technology, and in particular to a reconfigurable photonic crystal device for optical reasoning and classification and an implementation method thereof. Background Art

[0002] The diffractive optical neural network (DONN), proposed by Ozcan's team in 2018, consists of a series of transmissive or reflective metasurfaces arranged in a specific direction. The on-chip DONN, proposed by Chen's team in 2023, is based on a one-dimensional dielectric metasurface consisting of a series of silicon dioxide-filled silicon trenches. Each layer of diffraction elements can be considered an artificial neuron, connected to the diffraction elements in the next layer according to the Huygens-Fresnel diffraction law. As light passes through the diffraction elements, it is modulated by the amplitude and phase. By optimizing the amplitude or phase response of each diffraction element in a computer, the neural network can achieve desired functions such as image recognition and classification, and solving the system's eigenvalues. Furthermore, this system offers advantages such as speed-of-light processing and low energy consumption. It is important to note that light possesses multiple physical degrees of freedom, including wavelength, polarization, and orbital angular momentum. Wavelength, a key physical dimension of photons, can significantly enhance the parallel processing capabilities of optical computing when combined with wavelength division multiplexing technology. However, most of the existing DONNs are limited to single-wavelength working mode, and are unable to fully explore and utilize the huge potential contained in the multi-degree-of-freedom of the light field, and have obvious shortcomings in exerting the multi-degree-of-freedom characteristics of the light field. Summary of the Invention

[0003] The present invention provides a reconfigurable photonic crystal device for optical reasoning classification and its implementation method, which is used to overcome the defect that most existing DONNs in the prior art are limited to a single-wavelength operating mode, realize independent regulation of optical signals of different wavelengths, and form multiple groups of programmable wavelength channels.

[0004] The present invention provides a reconfigurable photonic crystal device for optical reasoning classification, comprising: a silicon-on-insulator substrate and a photonic crystal unit constructed on the silicon-on-insulator substrate and composed of first silicon pillars periodically arranged in a two-dimensional square lattice; wherein: the photonic crystal unit also includes a defect structure formed by removing an entire row of the first silicon pillars at the center of the photonic crystal unit, and a tunable defect silicon pillar located at the defect center of the defect structure and integrated with a micro-heater, and at least one second silicon pillar is distributed on both sides of the tunable defect silicon pillar along the lattice direction.

[0005] According to a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention, three second silicon pillars are symmetrically distributed along the lattice direction on both sides of the tunable defect silicon pillar.

[0006] According to a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention, the first spacing is twice the second spacing; wherein: the first spacing is the spacing between the center point of the second silicon column close to the tunable defective silicon column and the center point of the tunable defective silicon column; the second spacing is the spacing between the center points of two adjacent first silicon columns.

[0007] According to a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention, the variable diameter of the first silicon column is 126 nm, the lattice constant of the photonic crystal unit is 420 nm, the radius of the tunable defect silicon column is 161.54 nm, and the radius of the second silicon column is 156.15 nm.

[0008] According to a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention, the micro heater is a titanium nitride micro heater.

[0009] The present invention also provides a method for implementing a reconfigurable photonic crystal device for optical reasoning classification, including: applying voltage to a micro-heater to drive the refractive index change of a tunable defective silicon column, thereby causing a dynamic shift of the transmission peak of the input optical signal and continuous modulation of the output phase within a 2π range; and forming multiple groups of programmable wavelength channels according to the distribution of the transmission peak.

[0010] According to a method for implementing a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention, the wavelength range of the dynamic shift of the transmission peak is 1520-1620 nm.

[0011] According to a method for implementing a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention, the method also includes: mapping the transmittance and phase response of the programmable wavelength channel into the weight of the spatial convolution kernel, and weight programming the photonic crystal unit through preset refractive index-wavelength control parameters.

[0012] According to a method for implementing a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention, the method further includes: based on wavelength dimension parallelism, parallel processing of data of the multiple groups of programmable wavelength channels during a single light propagation process.

[0013] According to a method for implementing a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention, the method also includes: dynamically adjusting the refractive index of the tunable defective silicon column to achieve wavelength-selective light intensity control so that the output optical signal exhibits nonlinear output characteristics.

[0014] The reconfigurable photonic crystal device for optical reasoning classification provided by the present invention and its implementation method include a photonic crystal unit consisting of a silicon-on-insulator substrate and a first silicon column periodically arranged in a two-dimensional square lattice constructed on the silicon-on-insulator substrate. The photonic crystal unit also includes a defect structure formed by removing an entire row of the first silicon columns in the center of the photonic crystal unit, and a tunable defect silicon column located at the defect center of the defect structure and integrated with a micro-heater. At least one second silicon column is distributed on both sides of the tunable defect silicon column along the lattice direction. The refractive index of the silicon column at the defect center can be dynamically adjusted through the thermo-optical effect to achieve independent regulation of light signals of different wavelengths. It can achieve precise control of the transmission spectrum and phase response, form multiple groups of programmable wavelength channels, and simultaneously realize on-chip integration of multi-wavelength parallel convolution, all-optical nonlinear activation and diffraction light field modulation. It can be applied to medical image analysis, autonomous driving, high-efficiency optical computing chips and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 It is a schematic structural diagram of a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention.

[0017] Figure 2 It is a structural schematic diagram of a photonic crystal unit of a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention.

[0018] Figure 3 It is a structural schematic diagram of the defect structure center of the photonic crystal unit of the reconfigurable photonic crystal device for optical reasoning classification provided by the invention.

[0019] Figure 4 It is a flow chart of a method for implementing a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention.

[0020] Figure 5It is a schematic diagram of the transmission spectrum of the reconfigurable photonic crystal unit in the implementation method of the reconfigurable photonic crystal device for optical reasoning classification provided by the present invention.

[0021] Figure 6 It is a schematic diagram of the phase spectrum of the reconfigurable photonic crystal unit in the implementation method of the reconfigurable photonic crystal device for optical reasoning classification provided by the present invention.

[0022] Figure 7 It is a schematic diagram of the transmission spectrum of the reconfigurable photonic crystal device for optical reasoning classification provided by the present invention when the refractive index changes after applying different voltages. DETAILED DESCRIPTION

[0023] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0024] Photonic crystals (PhCs), as artificial bandgap materials, possess periodic dielectric structures that enable precise control of the localized photon density of states. Disruption of the periodic structure of a PhC creates defect modes within the photonic bandgap. These defect modes can localize photons of specific frequencies, enabling precise control of optical signals. By engineering defects, two-dimensional PhCs can generate high-Q resonant modes at specific wavelengths, providing an ideal platform for wavelength-selective modulation. Research has demonstrated that PhC-based microcavity arrays can be used to construct high-performance optical convolution kernels, and their compatibility with CMOS processes has further advanced the development of photonic integrated circuits. These properties make PhCs ideal devices for overcoming the wavelength limitations of traditional DONNs.

[0025] Although diffractive optical neural networks have demonstrated many advantages, they still have shortcomings in the utilization of multiple degrees of freedom of the light field and wavelength limitations. PhC, with its unique ability to precisely control optical signals, has brought new opportunities to solve the single-wavelength limitation of traditional DONNs. It is expected to become a key point in promoting further breakthroughs and development of DONN technology, and open up new paths for research and application in related fields.

[0026] To address the problems of low computational throughput and poor dynamic adjustability of traditional diffraction neural networks due to their single-wavelength operating mode, the present invention provides a reconfigurable photonic crystal device for optical reasoning and classification and its implementation method. The aim is to achieve independent regulation of optical signals of different wavelengths by designing the defect structure of the PhC and adjusting the refractive index of the silicon pillars in the PhC defect region.

[0027] Figure 1 It is a schematic structural diagram of a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention.

[0028] Figure 2 It is a structural schematic diagram of a photonic crystal unit of a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention.

[0029] Figure 3 It is a structural schematic diagram of the defect structure center of the photonic crystal unit of the reconfigurable photonic crystal device for optical reasoning classification provided by the invention.

[0030] like Figure 1 、 Figure 2 、 Figure 3 As shown, the reconfigurable photonic crystal device for optical reasoning classification includes a silicon-on-insulator substrate 1 and a photonic crystal unit 2 constructed on the silicon-on-insulator (SOI) substrate and composed of first silicon pillars 21 periodically arranged in a two-dimensional square lattice; wherein: the photonic crystal unit 2 also includes a defect structure 22 formed by removing an entire row of the first silicon pillars 21 in the center of the photonic crystal unit, and a tunable defect silicon pillar 23 located at the defect center of the defect structure 22 and integrated with a micro heater (not shown in the figure), and at least one second silicon pillar 24 is distributed on both sides of the tunable defect silicon pillar 23 along the lattice direction.

[0031] The reconfigurable photonic crystal device for optical reasoning and classification, proposed in this invention, is constructed on a silicon-on-insulator (SOI) substrate and features an electrically tunable defect structure based on a two-dimensional photonic crystal (PhC). This allows for dynamic control of multi-wavelength optical signals and all-optical nonlinear activation. The silicon pillar array of first silicon pillars 21 fabricated on the SOI substrate adopts a periodic two-dimensional square lattice arrangement. A tunable defect structure is introduced in the central region of the PhC as follows: an entire row of first silicon pillars 21 is removed to create a defect structure 22. A tunable defect silicon pillar 23 with a radius of R is positioned at the center of the defect, with a microheater integrated on top. At least one second silicon pillar 24 is distributed along the lattice on either side of the tunable defect silicon pillar 23.

[0032] The reconfigurable photonic crystal device provided by the present invention leverages the thermo-optic effect to dynamically adjust the refractive index of the tunable defective silicon pillar 23, thereby achieving precise control of the transmission spectrum and phase response. When voltage is applied to the microheater, the temperature of the tunable defective silicon pillar 23 increases, and its refractive index changes with temperature, causing the transmission peak to redshift. Simultaneously, the output phase can be continuously modulated within a 2π range. Furthermore, by adjusting the refractive index of the tunable defective silicon pillar 23, the transmission peak can be dynamically shifted within a certain range, forming multiple sets of programmable wavelength channels. This allows for the simultaneous on-chip integration of multi-wavelength parallel convolution, all-optical nonlinear activation, and diffracted light field modulation.

[0033] The reconfigurable photonic crystal device provided by this invention successfully implements multi-wavelength convolution and all-optical nonlinear activation based on a two-dimensional PhC, opening up new avenues for optical signal processing technology. Combining the advantages of programmability, electromagnetic interference resistance, and CMOS compatibility with the energy-efficient nature of diffraction computing, this photonic crystal device can be scalably applied to real-time multi-target tracking in autonomous driving (wavelength-encoded spatial coordinates), three-dimensional reconstruction of pathological sections (wavelength-mapped depth information), and terabit-per-second optical computing chips, providing core hardware support for optical artificial intelligence.

[0034] The reconfigurable photonic crystal device for optical reasoning and classification provided by the present invention comprises a silicon-on-insulator substrate and a photonic crystal unit composed of first silicon pillars periodically arranged in a two-dimensional square lattice, which is constructed on the silicon-on-insulator substrate; wherein: the photonic crystal unit also includes a defect structure formed by removing an entire row of first silicon pillars in the center of the photonic crystal unit, and a tunable defect silicon pillar located at the defect center of the defect structure and integrated with a micro-heater, at least one second silicon pillar is distributed on both sides of the tunable defect silicon pillar along the lattice direction, and the refractive index of the silicon pillar at the defect center can be dynamically adjusted through the thermo-optical effect to achieve independent regulation of light signals of different wavelengths, and can achieve precise control of the transmission spectrum and phase response to form multiple sets of programmable wavelength channels, and can simultaneously realize on-chip integration of multi-wavelength parallel convolution, all-optical nonlinear activation and diffraction light field modulation, which can be applied to medical image analysis, autonomous driving, high-efficiency optical computing chips and other fields.

[0035] According to a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention, three second silicon pillars 24 are symmetrically distributed on both sides of the tunable defect silicon pillar 23 along the lattice direction.

[0036] It has been verified that symmetrically distributing three second silicon pillars 24 on both sides of the tunable defect silicon pillar 23 along the lattice direction achieves a higher transmittance and a better effect.

[0037] The reconfigurable photonic crystal device for optical reasoning classification provided by the present invention achieves higher transmittance and improves the control effect of the reconfigurable photonic crystal device by symmetrically distributing three second silicon pillars on both sides of the tunable defect silicon pillar along the lattice direction.

[0038] According to a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention, the first spacing is twice the second spacing; wherein: the first spacing is the spacing between the center point of the second silicon column 24 close to the tunable defective silicon column 23 and the center point of the tunable defective silicon column 23; the second spacing is the spacing between the center points of two adjacent first silicon columns 21.

[0039] To localize the optical signal at the tunable defective silicon pillar 23, a certain distance must be placed between the second silicon pillar 24 near the tunable defective silicon pillar 23 and the center of the tunable defective silicon pillar 23. Experiments have shown that when the first spacing is twice the second spacing, more optical signals are localized at the tunable defective silicon pillar 23, resulting in better control of the reconfigurable photonic crystal device. This is achieved by setting the first spacing to be the distance between the center of the second silicon pillar 24 near the tunable defective silicon pillar 23 and the center of the tunable defective silicon pillar 23, and the second spacing to be the distance between the centers of two adjacent first silicon pillars 21.

[0040] The reconfigurable photonic crystal device for optical reasoning classification provided by the present invention further improves the control effect of the reconfigurable photonic crystal device by setting the distance between the center point of the second silicon column close to the tunable defect silicon column and the center point of the tunable defect silicon column to be twice the distance between the center points of the two adjacent first silicon columns.

[0041] According to a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention, the variable diameter of the first silicon column 21 is 126 nm, the lattice constant of the photonic crystal unit 2 is 420 nm, the radius of the tunable defect silicon column 23 is 161.54 nm, and the radius of the second silicon column 24 is 156.15 nm.

[0042] The experimental results show that when the variable diameter r of the first silicon column 21 is set to 126 nm, the lattice constant a of the photonic crystal unit 2 is 420 nm, the radius R of the tunable defect silicon column 23 is 161.54 nm, and the radius r of the second silicon column 24 is 161.54 nm, the lattice constant a of the photonic crystal unit 2 is 420 nm, and the radius R of the tunable defect silicon column 23 is 161.54 nm, the lattice constant a of the photonic crystal unit 2 is 420 nm, and the lattice constant a of the photonic crystal unit 2 is 420 ... h When the wavelength is 156.15 nm, the control effect of the reconfigurable photonic crystal device is better.

[0043] In addition, the height of the first silicon pillar 21 can be 220 nm, the unit coverage area of ​​the photonic crystal unit 2 can be 6×6 μm², and the photonic crystal unit 2 can be an 11*13 array, wherein the number of rows of the first silicon pillars 21 above and below the defect structure 22 is at least 5 rows, and after removing an entire row of the first silicon pillars 21 from the photonic crystal unit 2, a linear waveguide structure with a width of 2a-2r is formed.

[0044] When a voltage is applied to the micro heater, the temperature of the tunable defective silicon pillar 23 will change, and its refractive index changes in accordance with The relationship is as follows: Δn represents the change in refractive index, and ΔT represents the change in temperature. This refractive index modulation causes a redshift in the transmission peak in the defect mode, while the output phase is continuously regulated from 0 to 2π in the 1530-1620 nm band. By presetting voltage-wavelength mapping parameters, the transmittance and phase response of different wavelength channels can be programmably controlled, thus converting the wavelength selection property into an optical implementation of the convolution kernel weight matrix.

[0045] The reconfigurable photonic crystal device for optical reasoning classification provided by the present invention further improves the control effect of the reconfigurable photonic crystal device by setting the variable diameter of the first silicon column to 126 nm, the lattice constant of the photonic crystal unit to 420 nm, the radius of the tunable defect silicon column to 161.54 nm, and the radius of the second silicon column to 156.15 nm.

[0046] According to a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention, the microheater is a titanium nitride (TiN) microheater.

[0047] It has been verified that the micro heater integrated in the tunable defect silicon pillar 23 is a titanium nitride micro heater, and the thermo-optical effect of the tunable defect silicon pillar 23 is good. It is understandable that the micro heater integrated in the tunable defect silicon pillar 23 can also be other micro heaters.

[0048] The reconfigurable photonic crystal device for optical reasoning classification provided by the present invention further improves the control effect of the reconfigurable photonic crystal device by using a titanium nitride microheater as the microheater.

[0049] Figure 4 FIG. 1 is a flow chart of a method for implementing a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention. Figure 4 As shown, the method includes: Step S1: applying voltage to the micro heater to drive the refractive index of the tunable defective silicon column to change, thereby causing a dynamic shift of the transmission peak of the input optical signal and continuous modulation of the output phase within a 2π range.

[0050] Figure 5It is a schematic diagram of the transmission spectrum of the reconfigurable photonic crystal unit in the implementation method of the reconfigurable photonic crystal device for optical reasoning classification provided by the present invention. Figure 5 The horizontal axis is wavelength and the vertical axis is transmittance.

[0051] Figure 6 It is a schematic diagram of the phase spectrum of the reconfigurable photonic crystal unit in the implementation method of the reconfigurable photonic crystal device for optical reasoning classification provided by the present invention. Figure 6 The horizontal axis is wavelength and the vertical axis is phase (radians).

[0052] A reconfigurable photonic crystal device for optical reasoning and classification leverages the thermo-optic effect to dynamically adjust the refractive index of a tunable defective silicon pillar, enabling precise control of the transmission spectrum and phase response. When voltage is applied to a microheater, the temperature of the tunable defective silicon pillar increases, causing its refractive index to change with temperature, resulting in a redshift in the transmission peak. Simultaneously, the output phase can be continuously modulated over a 2π range.

[0053] Step S2: forming a plurality of sets of programmable wavelength channels according to the distribution of the transmission peaks.

[0054] like Figure 5 As shown, for a given refractive index, there are multiple transmission peaks. Based on the distribution of the transmission peaks, multiple sets of programmable wavelength channels can be formed, such as 32 sets of programmable wavelength channels. For example, wavelengths with transmittances greater than a preset threshold near a transmission peak can be identified as wavelengths corresponding to the multiple sets of programmable wavelength channels. The spacing between wavelengths corresponding to programmable wavelength channels near the same transmission peak can be 0.8 nm.

[0055] The present invention provides a method for implementing a reconfigurable photonic crystal device for optical reasoning and classification. By applying voltage to a microheater, the refractive index of a tunable defective silicon column is driven to change, thereby causing a dynamic shift in the transmission peak of an input optical signal and continuous modulation of the output phase within a 2π range. Multiple groups of programmable wavelength channels are formed according to the distribution of the transmission peaks, thereby achieving refractive index adjustment of the tunable defective silicon column, modulation of the transmission spectrum and phase response, and formation of multiple groups of programmable wavelength channels.

[0056] According to a method for implementing a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention, the wavelength range of the dynamic shift of the transmission peak is 1520-1620 nm.

[0057] It has been verified that, in the reconfigurable photonic crystal device structure for optical reasoning classification provided by the present invention, the wavelength range of the dynamic shift of the transmission peak is 1520-1620 nm. In other words, the wavelengths corresponding to the multiple sets of programmable wavelength channels are within this range.

[0058] The method for realizing a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention provides the wavelength ranges of multiple groups of programmable wavelength channels by determining the wavelength range of the dynamic shift of the transmission peak.

[0059] According to a method for implementing a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention, the transmittance and phase response of the programmable wavelength channel are mapped to the weight of the spatial convolution kernel, and the photonic crystal unit is weight-programmed by pre-setting the refractive index-wavelength control parameters.

[0060] For reconfigurable photonic crystal devices used for optical reasoning and classification, the refractive index of the photonic crystal unit is dynamically controlled through the thermo-optical effect, and the transmittance and phase synchronous modulation of multi-wavelength programmable channels are achieved in the 1520-1620 nm band. The transmittance and phase response of the programmable wavelength channels are mapped to the weights of the spatial convolution kernel, and the photonic crystal unit is weight-programmed using preset refractive index-wavelength control parameters.

[0061] The dynamic modulation of the effective refractive index of the tunable defective silicon pillars is precisely mapped to the weight adjustment mechanism of the photonic crystal unit. By using multiple sets of refractive index control parameters corresponding to the input wavelengths, the photonic crystal unit can simultaneously perform differentiated spatial convolution kernel operations on multi-wavelength optical signals.

[0062] The present invention provides a method for implementing a reconfigurable photonic crystal device for optical reasoning classification. By mapping the transmittance and phase response of a programmable wavelength channel into the weight of a spatial convolution kernel, the photonic crystal unit is weight-programmed using preset refractive index-wavelength control parameters, thereby achieving weight programming of the photonic crystal unit.

[0063] According to a method for implementing a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention, the method further includes: based on wavelength dimension parallelism, parallel processing of data of the multiple groups of programmable wavelength channels during a single light propagation process.

[0064] Leveraging wavelength-dimensional parallelism, this approach processes data from multiple sets of programmable wavelength channels in parallel during a single optical transmission. For n sets of programmable wavelength channels, the computational throughput is increased by a factor of n compared to traditional single-wavelength approaches. Experimental results show that this approach, through a combined wavelength-space modulation mechanism, achieves multi-channel parallel inference within a single optical transmission, increasing computational throughput by a factor of 32 compared to traditional approaches.

[0065] The present invention provides a method for implementing a reconfigurable photonic crystal device for optical reasoning classification, which improves computational throughput by processing data of multiple sets of programmable wavelength channels in parallel during a single light propagation based on wavelength-dimensional parallelism.

[0066] According to a method for implementing a reconfigurable photonic crystal device for optical reasoning classification provided by the present invention, the method also includes: dynamically adjusting the refractive index of the tunable defective silicon column to achieve wavelength-selective light intensity control so that the output optical signal exhibits nonlinear output characteristics.

[0067] For a given wavelength, the refractive index and transmittance exhibit a nonlinear relationship similar to an exponential function. Transmittance determines the intensity of the optical signal. Dynamic refractive index adjustment of tunable defective silicon pillars enables wavelength-selective light intensity control, directly mapping light intensity to nonlinear output characteristics. The synergistic effect of the wavelength-dependent nonlinear output characteristics and the cascaded diffraction structure enables all-optical nonlinear computing.

[0068] By adjusting the voltage applied to the micro heater, the diffraction neural network all-optical device (reconfigurable photonic crystal device cascaded diffraction optical neural network) can dynamically and tunably realize parallel computing and nonlinear activation functions.

[0069] The present invention provides a method for implementing a reconfigurable photonic crystal device for optical reasoning classification. By dynamically adjusting the refractive index of a tunable defective silicon column, wavelength-selective light intensity control is achieved, so that the output optical signal exhibits nonlinear output characteristics, thereby realizing nonlinear calculation.

[0070] Figure 7 It is a schematic diagram of the transmission spectrum of the reconfigurable photonic crystal device for optical reasoning classification provided by the present invention when the refractive index changes after applying different voltages. Figure 7 The horizontal axis is the refractive index and the vertical axis is the transmittance.

[0071] To verify the optical control performance of the reconfigurable photonic crystal unit, this embodiment performs full-band electromagnetic simulation based on the finite-difference time-domain (FDTD) method to obtain the quantitative relationship between the transmission spectrum and the phase spectrum; a perfectly matched layer (PML) is set along the main direction (Γ-X) of the lattice and in the vertical direction; the input light source is TM polarization mode (wavelength range 1525-1625 nm); the refractive index of the central defect silicon column (tunable defect silicon column 23) is gradient scanned (refractive index n=3.46-3.50, step size Δn=0.001), and the steady-state light field distribution is calculated independently for each set of parameters; Figure 5As shown in Figure 1, when the refractive index of the central silicon pillar increases from 3.48 to 3.50, the transmission peak red-shifts from 1546.68 nm to 1551.24 nm, with a wavelength shift of Δλ=4.56 nm. In the initial state (n=3.48), the device exhibits three high transmittance peaks at 1546.68 nm, 1582.72 nm, and 1593.55 nm. By adjusting the refractive index, the transmission peak can be continuously shifted within the range of 1530-1620 nm, forming a programmable wavelength channel that covers the C-band communication window. Figure 6 As shown in , the same refractive index change enables the phase to achieve continuous coverage of 0-2π in the 1530-1620 nm band; Figure 7 As shown, when the refractive index of the central defect silicon column is dynamically controlled (n=3.46-3.50), the transmission spectrum of the reconfigurable photonic crystal unit of the present invention exhibits programmable wavelength selectivity. By voltage-controlled refractive index of the central defect silicon column, the device can achieve fine control between wavelength channels while maintaining high transmittance. Combined with the preset voltage-wavelength-transmittance mapping parameters, the photonic crystal unit can be equivalent to a programmable spatial convolution kernel, and the computing throughput can be increased by 32 times compared with the traditional single-wavelength solution, providing a physical basis for multimodal optical computing.

[0072] The reconfigurable photonic crystal all-optical device proposed in this paper achieves on-chip integration of multi-wavelength parallel convolution and all-optical nonlinear activation through dynamic control of defect structures. Its high transmittance, low crosstalk, fast response, and CMOS compatibility provide a solution to overcome the energy efficiency bottleneck of traditional electronic computing. This technology has broad applications in areas such as real-time multi-target tracking (wavelength-encoded spatial coordinates) for autonomous driving, high-resolution medical image processing (multispectral feature fusion), and next-generation optical communications (terabit-per-second all-optical switching). It is expected to promote the development of optical intelligent computing to larger scales and higher dimensions, laying the core hardware foundation for the deep integration of artificial intelligence and the optoelectronic information industry.

[0073] The reconfigurable photonic crystal device for optical reasoning classification provided by the present invention has the following advantages over existing technologies: (1) High integration: The present invention integrates multi-wavelength convolution operation, all-optical nonlinear activation and dynamic tuning functions into the photonic crystal unit, realizing the integration of diffraction calculation and optical modulation.

[0074] (2) Multi-wavelength parallel processing: Wavelength-dimensional parallel computing is achieved based on 32 sets of programmable wavelength channels, and the computing throughput is increased by 32 times compared with the single-wavelength diffraction network.

[0075] (3) All-optical nonlinear activation effect: The dynamic refractive index adjustment of PhC can realize wavelength-selective light intensity control, directly mapping the light intensity into nonlinear output characteristics, and synchronously completing convolution and activation operations.

[0076] (4) Dynamic reconfigurability: The TiN microheater precisely and electrically adjusts the refractive index of the tunable defective silicon column of the photonic crystal unit, shifting the transmission peak wavelength and rapidly updating the convolution kernel weights.

[0077] (5) Broad application prospects: Through the wavelength-space joint modulation model, the present invention demonstrates strong adaptability in scenarios such as medical field (pathological feature recognition), intelligent transportation (multi-target tracking), industrial detection and quantum computing.

[0078] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units. That is, they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0079] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A reconfigurable photonic crystal device for optical reasoning classification, characterized in that: include: A silicon-on-insulator substrate and a photonic crystal unit constructed on the silicon-on-insulator substrate and composed of first silicon pillars periodically arranged in a two-dimensional square lattice; wherein: the photonic crystal unit also includes a defect structure formed by removing an entire row of the first silicon pillars at the center of the photonic crystal unit, and a tunable defect silicon pillar located at the defect center of the defect structure and with an integrated microheater, and at least one second silicon pillar is distributed on both sides of the tunable defect silicon pillar along the lattice direction.

2. The reconfigurable photonic crystal device for optical reasoning classification according to claim 1, characterized in that: Three second silicon pillars are symmetrically distributed on both sides of the tunable defect silicon pillar along the lattice direction.

3. The reconfigurable photonic crystal device for optical reasoning classification according to claim 2, characterized in that: The first spacing is twice the second spacing; where: The first distance is the distance between the center point of the second silicon column close to the tunable defective silicon column and the center point of the tunable defective silicon column; The second distance is the distance between the center points of two adjacent first silicon pillars.

4. The reconfigurable photonic crystal device for optical reasoning classification according to any one of claims 1 to 3, characterized in that: The variable diameter of the first silicon column is 126 nm, the lattice constant of the photonic crystal unit is 420 nm, the radius of the tunable defect silicon column is 161.54 nm, and the radius of the second silicon column is 156.15 nm.

5. The reconfigurable photonic crystal device for optical reasoning classification according to claim 1, characterized in that: The micro heater is a titanium nitride micro heater.

6. A method for implementing a reconfigurable photonic crystal device for optical reasoning classification according to any one of claims 1 to 5, characterized in that: include: By applying voltage to the micro heater, the refractive index of the tunable defective silicon pillar is driven to change, which causes the dynamic shift of the transmission peak of the input optical signal and the continuous modulation of the output phase within the range of 2π. A plurality of groups of programmable wavelength channels are formed according to the distribution of the transmission peaks.

7. The method for implementing a reconfigurable photonic crystal device for optical reasoning classification according to claim 6, characterized in that: The wavelength range of the transmission peak dynamic shift is 1520-1620 nm.

8. The method for implementing a reconfigurable photonic crystal device for optical reasoning classification according to claim 6, characterized in that: The method further comprises: The transmittance and phase response of the programmable wavelength channel are mapped to the weight of the spatial convolution kernel, and the weight programming of the photonic crystal unit is performed by presetting the refractive index-wavelength control parameters.

9. The method for implementing a reconfigurable photonic crystal device for optical reasoning classification according to claim 6, characterized in that: The method further comprises: Based on wavelength-dimensional parallelism, data of the multiple groups of programmable wavelength channels are processed in parallel during a single optical propagation process.

10. The method for implementing a reconfigurable photonic crystal device for optical reasoning classification according to claim 6, characterized in that: The method further comprises: By dynamically adjusting the refractive index of the tunable defective silicon column, wavelength-selective light intensity control is achieved, so that the output optical signal exhibits nonlinear output characteristics.

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