Photon integrated spatial light receiver and optical implementation method thereof

Abstract

The invention relates to the technical field of optical communication, and provides a photon integrated spatial light receiver which comprises a metasurface dynamic wavefront correction layer and an inverse design multimode interference coupler. The metasurface dynamic wavefront correction layer focuses the spatial light into a focusing light spot as an input light field of the inverse design multimode interference coupler. Orthogonal modes in an input light field are effectively demultiplexed into multiple paths of independent light fields to be output through an inverse design multimode interference coupler, and each path of light field is further converted into a waveguide base mode to be output through a corresponding waveguide channel. According to the invention, efficient light field receiving, dynamic wavefront correction and multimode diversity output are realized, and the performance of a space optical communication system is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the field of optical communication technology, and in particular to a photon-integrated spatial optical receiver based on the coordinated operation of a metasurface and a waveguide coupling and an optical implementation method thereof. Background Art

[0002] Free-space optical communication uses laser beams as carrier waves to transmit information in space. It boasts high communication capacity, strong confidentiality, and excellent resistance to electromagnetic interference. However, as laser signals pass through the Earth's atmosphere, they are affected by atmospheric effects such as turbulence. This causes light wave intensity attenuation and random phase jitter, leading to beam drift and spot spread, which can severely impact communication quality and even cause communication interruption. Light wave intensity attenuation weakens the signal, potentially below the receiver's recognizable threshold. Random phase jitter, beam drift, and spot spread undermine the stability and accuracy of the optical signal, making it difficult for the receiver to accurately interpret the signal.

[0003] To address these issues, traditional spatial optical receivers employ a variety of technologies, but each has its own drawbacks. Single-mode fiber receivers rely on complex control algorithms to improve coupling efficiency, but this limits loop bandwidth and impacts system transmission efficiency. Few-mode fiber receivers couple spatial light into a few-mode fiber and then project it onto the fiber's fundamental mode through a spatial demultiplexer. While this approach reduces the probability of overall communication interruption due to a single signal interruption, it requires a corresponding coherent receiver to be connected to each single-mode fiber, resulting in high costs and limited system scalability.

[0004] Furthermore, traditional grating couplers and subwavelength holographic surface gratings also have limitations in on-chip spatial optical receiver applications. Grating couplers rely on fixed geometric structures, making them less adaptable to beams of varying wavelengths or angles. Subwavelength holographic surface gratings, while offering high resolution and compact size, are complex to design and manufacture, presenting significant challenges in achieving efficient coupling and struggling to maintain stable performance during signal transmission.

[0005] Therefore, there is an urgent need for a photon-integrated spatial light receiving solution with multi-dimensional dynamic adaptation capability, high integration, and high coupling efficiency to achieve efficient dynamic adaptation of free-space light and photon-integrated waveguides. Summary of the Invention

[0006] The object of the present invention is to provide a photonic integrated spatial light receiver, comprising a metasurface dynamic wavefront correction layer and an inverse-designed multimode interference coupler, wherein the inverse-designed multimode interference coupler forms a mode demultiplexing conversion channel; the metasurface dynamic wavefront correction layer focuses spatial light into a focused light spot, and the focused light spot serves as the input light field of the inverse-designed multimode interference coupler; through the inverse-designed multimode interference coupler, each orthogonal mode in the input light field is effectively demultiplexed into multiple independent light field outputs, and each light field is further converted into a waveguide fundamental mode and output respectively through the corresponding waveguide channel.

[0007] According to one embodiment of the present invention, the focus of the metasurface dynamic wavefront correction layer coincides with the center of the inverse-designed multimode interference coupler, so that the metasurface dynamic wavefront correction layer inputs the focused light spot into the center of the inverse-designed multimode interference coupler.

[0008] According to one embodiment of the present invention, the metasurface dynamic wavefront correction layer is composed of a two-dimensional nanocolumn array and a base material. The two-dimensional nanocolumn array is composed of a plurality of nanocolumns with subwavelength scales, and the two-dimensional nanocolumn array is fixed on the base material.

[0009] According to one embodiment of the present invention, the heights of the plurality of nanopillars in the two-dimensional nanopillar array are the same; when the heights are determined, the nanopillars are arranged according to a specific phase, and the phases of the nanopillars at corresponding positions are determined according to the following formula: in, Arrange the corresponding positions The phase of the nanopillars on is the target focal length of the metasurface dynamic wavefront correction layer, is the distance between the edge of the incident light of the metasurface dynamic wavefront correction layer and the optical axis of the metasurface dynamic wavefront correction layer, is the vacuum wavelength, The refractive index of the material used for the nanopillars of the metasurface dynamic wavefront correction layer, ∈(0, the number of rows in the two-dimensional nanopillar array - 1) and ∈ (0, the number of columns in the two-dimensional nanocolumn array - 1) corresponds to the position of the nanocolumns in the two-dimensional nanocolumn array.

[0010] According to one embodiment of the present invention, the inverse-designed multimode interference coupler is a three-layer vertical structure consisting of a spatial optical coupler, a substrate layer, and a metal reflective layer. The spatial optical coupler is arranged on one side of the substrate layer, and the metal reflective layer is deposited on the other side of the substrate layer by a sputtering process.

[0011] According to one embodiment of the present invention, the thickness of the substrate layer of the inverse-designed multimode interference coupler is determined according to the following formula: in, is the thickness of the substrate layer, is the wavelength of incident light, is the refractive index of the material used for the substrate layer, is the number of cycles.

[0012] According to one embodiment of the present invention, the metasurface dynamic wavefront correction layer is a metalens.

[0013] In this photonic integrated spatial light receiver, the metalens and spatial optical coupler work together to effectively expand the spatial light receiving area and improve the system's duty cycle, thereby achieving more efficient spatial light coupling performance. Furthermore, integrating the metalens with the inversely designed multimode interference coupler on the same photonic chip not only improves the system's alignment tolerance to incident spatial light but also reduces the overall structural complexity of the system, providing strong support for the integration of high-density, high-stability on-chip optical systems.

[0014] The present invention also provides an optical implementation method of a photon-integrated spatial light receiver, which is used for the photon-integrated spatial light receiver of the above-mentioned embodiment. The method includes: receiving spatial light through a metasurface dynamic wavefront correction layer, and focusing the spatial light into a focused light spot; inputting the focused light spot as an input light field into an inverse-designed multimode interference coupler through the metasurface dynamic wavefront correction layer; effectively demultiplexing the orthogonal modes in the input light field into multiple independent light field outputs through the inverse-designed multimode interference coupler, and further converting each light field into a waveguide fundamental mode, and outputting them respectively through the corresponding waveguide channels.

[0015] According to one embodiment of the present invention, the inverse-designed multimode interference coupler is used to effectively demultiplex the orthogonal modes in the input light field into multiple independent light field outputs, and specifically includes: performing mode decomposition on the input light field through the inverse-designed multimode interference coupler to generate multiple mode lights, and separating the different mode lights into corresponding waveguide channels; wherein the multiple waveguide channels correspond to different modes respectively.

[0016] According to one embodiment of the present invention, each light field is further converted into a waveguide fundamental mode and outputted through the corresponding waveguide channel. Specifically, for each mode light, a mode overlap integral method is used to spatially match the input mode with the waveguide fundamental mode to achieve maximum efficiency; based on a convex optimization algorithm, a micro-nanostructure is designed to meet the high coupling efficiency requirements of multiple mode conversions.

[0017] The optical implementation method of the photon-integrated spatial light receiver of the present invention utilizes an inverse design method for a spatial optical coupler to expand the number of modes, achieve mode selectivity, efficiently convert light spots, have strong multi-modal support and efficient coupling capabilities, and have stable performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] 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.

[0019] Figure 1 It is a schematic cross-sectional view of the three-dimensional heterogeneous integrated architecture of the photon integrated spatial light receiver of the present invention.

[0020] Figure 2 This is a scanning electron microscope (SEM) characterization image of the sub-wavelength phase control layer structure of the metasurface dynamic wavefront correction layer of the present invention.

[0021] Figure 3 This is a scanning electron microscope (SEM) characterization image of the three-dimensional heterogeneous integrated structure of the four-channel inverse design multi-mode interference coupler based on the convex optimization algorithm of the present invention.

[0022] Description of reference numerals: 1. Nanopillars; 2. Two-dimensional nanopillar array; 3. Substrate material; 4. Waveguide channel; 5. Spatial optical coupler; 6. Metal reflective layer; 7. Substrate layer; 8. Metasurface dynamic wavefront correction layer; 9. Inversely designed multimode interference coupler; 10. Photonic integrated spatial optical receiver. 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] The following combination Figure 1-Figure 3 The present invention describes a photon-integrated spatial optical receiver and an optical implementation method of the photon-integrated spatial optical receiver.

[0025] The present invention provides a photon-integrated spatial light receiver 10, which includes a metasurface dynamic wavefront correction layer 8 and an inverse-designed multimode interference coupler 9, wherein the inverse-designed multimode interference coupler 9 forms a mode demultiplexing conversion channel; the metasurface dynamic wavefront correction layer 8 focuses spatial light into a focused light spot, which serves as the input light field of the inverse-designed multimode interference coupler 9; through the inverse-designed multimode interference coupler 9, each orthogonal mode in the input light field is effectively demultiplexed into multiple independent light field outputs, and each light field is further converted into a waveguide fundamental mode and output respectively through the corresponding waveguide channel 4.

[0026] Specifically, the present invention provides a photon-integrated spatial optical receiver 10, which exhibits unique and powerful functional characteristics in the field of optical communications. This photon-integrated spatial optical receiver 10 primarily comprises a metasurface dynamic wavefront correction layer 8 and an inverse-designed multimode interference coupler 9, which work closely together to achieve efficient reception of spatial optical signals.

[0027] The structural design of the inverse-engineered multimode interference coupler 9 is particularly critical. Its internal structure features carefully constructed mode demultiplexing and conversion channels. These channels are crucial for achieving optical signal mode conversion and efficient transmission. They accurately convert input optical signals into fundamental mode optical signals suitable for waveguide transmission according to specific rules and methods, ensuring stable subsequent optical signal transmission.

[0028] The metasurface dynamic wavefront correction layer 8 is like a precise optical "super lens" with excellent focusing capabilities. When spatial light enters the system, the metasurface dynamic wavefront correction layer 8 can dynamically correct the wavefront of the spatial light, thereby accurately focusing the spatial light into a focused light spot. The quality of this focused light spot directly affects the effect of subsequent optical signal processing, and the metasurface dynamic wavefront correction layer 8, with its special micro-nano structure and design, ensures that the focused light spot has high energy concentration and stability. Afterwards, the focused light spot serves as the input light field of the inverse-designed multimode interference coupler 9, providing the initial conditions for subsequent optical signal conversion and processing.

[0029] After receiving the input light field of the focused light spot, the inversely designed multimode interference coupler 9 performs its core conversion function. It can effectively demultiplex the orthogonal modes in the input light field into multiple independent light field outputs, and further convert each light field into a waveguide fundamental mode, which is output separately through the corresponding waveguide channel. In this way, an efficient conversion from a complex spatial light field to a multi-channel single-mode waveguide fundamental mode light field is achieved. Subsequently, these multiple light field outputs are output separately through the corresponding waveguide channel 4. As the "highway" for optical signal transmission, the waveguide channel 4 transmits the converted optical signal stably and quickly to the subsequent optical communication system module, ensuring the stable operation of the entire optical communication link.

[0030] Figure 1 It is a schematic cross-sectional view of the three-dimensional heterogeneous integrated architecture of the photon integrated spatial light receiver of the present invention.

[0031] Preferably, if Figure 1 As shown, the focus of the metasurface dynamic wavefront correction layer 8 coincides with the center of the inverse-designed multimode interference coupler 9, so that the metasurface dynamic wavefront correction layer 8 inputs the focused light spot into the center of the inverse-designed multimode interference coupler 9.

[0032] Specifically, refer to Figure 1 Let’s learn in detail about the exquisite coordination of each key component in the photonic integrated spatial optical receiver 10. Figure 1 The positional relationship between the metasurface dynamic wavefront correction layer 8 and the inverse-designed multimode interference coupler 9 in the entire system and their collaborative working mechanism are clearly demonstrated.

[0033] A crucial design key in this embodiment is the precise alignment of the focus of the metasurface dynamic wavefront correction layer 8 with the center of the inverse-designed multimode interference coupler 9. This precise alignment is not accidental, but the result of meticulous design and rigorous calibration. Actual manufacturing and integration requires the use of high-precision optical positioning technology and advanced micro-nanofabrication techniques.

[0034] The metasurface dynamic wavefront correction layer 8 focuses the spatial light into a focused spot. This focused spot carries the information contained in the spatial light and has a high energy density. Because the focal point coincides with the center of the inverse-designed multimode interference coupler 9, this focused spot can be precisely input into the center of the inverse-designed multimode interference coupler 9.

[0035] After receiving the focused light spot, the inverse-designed multimode interference coupler 9 begins further processing. Using its carefully designed internal micro-nanostructure, it effectively demultiplexes the orthogonal modes of the input light field into multiple independent light field outputs. It then further converts each light field into a waveguide fundamental mode, which is then output via its corresponding waveguide channel. In this way, the inverse-designed multimode interference coupler 9 achieves mode decomposition and conversion of spatial light, laying the foundation for subsequent optical signal processing and transmission.

[0036] Figure 2 This is a scanning electron microscope (SEM) characterization image of the sub-wavelength phase control layer structure of the metasurface dynamic wavefront correction layer of the present invention.

[0037] Preferably, if Figure 2 As shown, the metasurface dynamic wavefront correction layer 8 is composed of a two-dimensional nanocolumn array 2 and a base material 3 . The two-dimensional nanocolumn array 2 is composed of a plurality of nanocolumns 1 with subwavelength dimensions. The two-dimensional nanocolumn array 2 is fixed on the base material 3 .

[0038] The metasurface dynamic wavefront correction layer 8 exhibits a unique and exquisite microstructure, which is composed of a two-dimensional nanocolumn array 2 and a substrate material 3. The two complement each other and together give the metasurface dynamic wavefront correction layer 8 excellent optical properties.

[0039] Specifically, the two-dimensional nanopillar array 2 plays a core role in the entire metasurface dynamic wavefront correction layer 8. This array is composed of multiple closely arranged nanopillars 1 with subwavelength scales. The scale of these nanopillars 1 is at the subwavelength level, which means that their size is on the same order of magnitude as the wavelength of light or even smaller. This characteristic gives them special optical effects. During the manufacturing process, advanced micro-nano processing technologies such as electron beam lithography and nanoimprinting can be used to precisely control the shape, size, and spacing of the nanopillars 1. The height, radius, and period between each nanopillar 1 are carefully designed and strictly controlled. For example, the height of the nanopillar 1 may be between tens and hundreds of nanometers, and the radius is also controlled in the range of a few nanometers to tens of nanometers, while the period between them is precisely adjusted within the subwavelength scale according to the required optical function. These nanopillars 1 are not arranged randomly, but form a two-dimensional array according to specific phase distribution rules. This orderly arrangement enables the two-dimensional nanopillar array 2 to precisely control the phase of the incident light.

[0040] The two-dimensional nanopillar array 2 is fixed on the base material 3, which plays a key role in supporting and protecting the two-dimensional nanopillar array 2. The selection of the base material 3 is crucial. It needs to have good optical transparency to ensure that the energy loss of light is minimized during propagation. At the same time, the physical and chemical properties of the base material 3 must be stable and able to maintain its own characteristics under different environmental conditions, providing a stable support environment for the two-dimensional nanopillar array 2. In this embodiment, the base material 3 may be a common optical material such as silica. Silica has excellent optical uniformity and chemical stability, and can well meet the working requirements of the metasurface dynamic wavefront correction layer 8. When fixing the two-dimensional nanopillar array 2 on the base material 3, a special material bonding process, such as chemical vapor deposition, atomic layer deposition and other technologies, is used to form a strong and stable bond between the two-dimensional nanopillar array 2 and the base material 3, ensuring that the two-dimensional nanopillar array 2 will not be displaced or fall off under the action of light, thereby ensuring that the optical performance of the metasurface dynamic wavefront correction layer 8 is stable and reliable. This structural design enables the metasurface dynamic wavefront correction layer 8 to effectively perform dynamic correction on the wavefront of spatial light, achieve flexible control of the light field, and lay a solid foundation for the efficient operation of the photonic integrated spatial light receiver 10.

[0041] Preferably, the heights of the multiple nanopillars 1 of the two-dimensional nanopillar array 2 are the same; when the heights are determined, the nanopillars 1 are arranged according to a specific phase, and the phases of the nanopillars 1 at corresponding positions are determined according to the following formula: in, Arrange the corresponding positions The phase of nanopillar 1 on is the target focal length of the metasurface dynamic wavefront correction layer 8, is the distance between the incident light edge of the metasurface dynamic wavefront correction layer 8 and the optical axis of the metasurface dynamic wavefront correction layer 8, is the vacuum wavelength, is the refractive index of the material used for the nanorods 1 of the metasurface dynamic wavefront correction layer 8, ∈(0, number of rows in the two-dimensional nanopillar array 2 - 1) and ∈ (0, the number of columns in the two-dimensional nanopillar array 2 - 1) corresponds to the position of nanopillar 1 in the two-dimensional nanopillar array 2.

[0042] Specifically, for the two-dimensional nanopillar array 2 in the metasurface dynamic wavefront correction layer 8, its structural design has clear and precise rules. In this embodiment, the multiple nanopillars 1 in the two-dimensional nanopillar array 2 have the same height. This highly consistent design is not arbitrary, but is to ensure that the entire two-dimensional nanopillar array 2 can achieve specific optical functions based on a unified physical basis when regulating the light field. When all nanopillars 1 are the same height, in the subsequent arrangement and parameter setting of the nanopillars 1, it is more convenient to perform precise control based on optical principles and design goals, avoiding the interference of additional complex factors caused by height differences on the light field regulation effect.

[0043] Under the premise of high certainty, the nanopillars 1 need to be arranged in a specific phase. The specific phase arrangement here is carefully designed based on the optical function requirements of the metasurface dynamic wavefront correction layer 8. One of the core functions of the metasurface is to precisely control the wavefront of the incident light, and the phase arrangement of the nanopillars 1 is the key factor in achieving this control. By rationally arranging the phase distribution of the nanopillars 1, the metasurface can flexibly adjust the phase, amplitude and other characteristics of the incident light, thereby realizing a variety of optical functions such as focusing, beam deflection, and wavefront shaping. This specific phase arrangement is obtained through complex optical simulations and theoretical calculations, and is intended to enable the metasurface to achieve optimal optical performance under specific working wavelengths and incident conditions.

[0044] Furthermore, the phase of the nanopillar 1 at the corresponding position is determined according to an accurate formula. This formula is: in, Represents the corresponding arrangement position ( ). This phase parameter is crucial for nanopillars 1 to regulate the light field. Different phases will lead to different interactions between nanopillars 1 and incident light, thus affecting the propagation of light and phase changes.

[0045] The target focal length of the metasurface dynamic wavefront correction layer 8 determines the metasurface's ability to focus incident light. The target focal length is determined based on the specific metasurface application and optical design requirements. For example, in some optical communications or imaging systems, a specific focal length is required to achieve optimal signal transmission or image quality.

[0046] is the distance between the edge of the incident light on the metasurface dynamic wavefront correction layer 8 and the optical axis of the metasurface dynamic wavefront correction layer 8. This distance reflects the distribution range and position information of the incident light on the metasurface. When the incident light at different positions interacts with the nanopillar 1, Different values produce different optical responses.

[0047] The vacuum wavelength is a fundamental property of light, with different vacuum wavelengths corresponding to light of different colors and frequencies. When designing metasurfaces, the operating wavelength range must be considered to ensure that the parameters of the nanopillars 1 can effectively control light within this wavelength range.

[0048] The refractive index of the material used for the nanopillars 1 in the metasurface dynamic wavefront correction layer 8. Refractive index is a key optical parameter of a material, determining the speed and direction of light propagating through it. Different materials have different refractive indices. By selecting the appropriate material and controlling its refractive index, the nanopillars' ability to manipulate the light field can be further optimized.

[0049] ∈(0,number of rows in the two-dimensional nanopillar array-1) and ∈ (0, the number of columns in the two-dimensional nanopillar array 2 - 1) corresponds to the position of nanopillar 1 in the two-dimensional nanopillar array 2. This means that for each nanopillar 1 in the two-dimensional nanopillar array 2, its coordinates in the array can be To accurately determine its position, the phase of the nanopillar 1 at that position is calculated according to the above formula. This precise position correspondence and phase calculation method enables the entire two-dimensional nanopillar array 2 to accurately correct and control the wavefront of incident light according to design requirements, thereby realizing the expected optical function of the metasurface dynamic wavefront correction layer 8.

[0050] Specifically, in the actual design and manufacturing process, it is first necessary to determine the target focal length according to the application requirements of the metasurface. , working vacuum wavelength and the refractive index of the material used in the nanorod 1 Then, according to the number of rows and columns of the two-dimensional nanopillar array 2, the position coordinates of each nanopillar 1 are determined. Then, the distance between the edge of the incident light and the optical axis is obtained by measuring or calculating Finally, these parameters are substituted into the above formula to calculate the phase of each nanopillar 1 When manufacturing the two-dimensional nanopillar array 2, advanced micro-nanofabrication techniques, such as electron beam lithography and focused ion beam machining, are utilized to precisely fabricate each nanopillar 1 according to the calculated phase and position information, thereby enabling the precise design and fabrication of the metasurface dynamic wavefront correction layer 8. The resulting metasurface dynamic wavefront correction layer 8 can efficiently and accurately correct and control the wavefront of incident light in practical applications, providing strong support for improving the performance of optical systems such as the photonic integrated spatial light receiver 10.

[0051] Figure 3 This is a scanning electron microscope (SEM) characterization image of the three-dimensional heterogeneous integrated structure of the four-channel inverse design multi-mode interference coupler based on the convex optimization algorithm of the present invention.

[0052] Preferably, if Figure 3 As shown, the inverse-designed multimode interference coupler 9 is a three-layer vertical structure consisting of a spatial optical coupler 5, a substrate layer 7, and a metal reflective layer 6. The spatial optical coupler 5 is arranged on one side of the substrate layer 7, and the metal reflective layer 6 is deposited on the other side of the substrate layer 7 by a sputtering process.

[0053] Specifically, the spatial optical coupler 5, as a core component, is carefully arranged on one side of the substrate layer 7. The spatial optical coupler 5 plays a key bridging role in the entire structure, and is responsible for efficiently coupling the spatial light into the waveguide to achieve effective transmission of the optical signal. When manufacturing the spatial optical coupler 5, advanced micro-nano processing technologies, such as electron beam lithography and reactive ion etching, are used to precisely control the shape, size and spacing of its micro-nano structure. These micro-nano structures are arranged according to a specific optical design, and can accurately control the light field of the incident spatial light, accurately guide it to the waveguide channel 4, and ensure the transmission efficiency and quality of the optical signal. Its design is based on complex optical theory and inverse design algorithms. By optimizing the micro-nano structure parameters, the spatial optical coupler 5 can achieve the best coupling effect for different orthogonal modes.

[0054] The substrate layer 7 provides a stable and reliable support platform for the spatial optical coupler 5. The substrate layer 7 must possess excellent optical and mechanical properties. On the one hand, it must ensure low light loss during propagation within it, and on the other hand, it must be able to withstand various processing steps during the manufacturing process and maintain structural stability during long-term use. In this embodiment, the substrate layer 7 may be made of a material such as silicon dioxide, which has excellent optical uniformity and chemical stability. When preparing the substrate layer 7, mature processes such as chemical vapor deposition are employed to grow a uniform, high-quality thin film on the substrate, laying the foundation for the subsequent processing of the spatial optical coupler 5 and the metal reflective layer 6.

[0055] The metal reflective layer 6 is deposited on the other side of the substrate layer 7 by a sputtering process. The sputtering process is a physical vapor deposition technology that can uniformly deposit a layer of metal film on the surface of the substrate layer 7. When selecting metal materials, high reflectivity and good conductivity are usually considered, such as metals such as gold and silver. The role of the metal reflective layer 6 is very critical. It can reflect the optical signal that may leak in the substrate layer 7 back to the waveguide channel 4, reduce the loss of the optical signal, and improve the coupling efficiency of the optical signal. In this way, through the coordinated work of the spatial optical coupler 5, the substrate layer 7 and the metal reflective layer 6, the inversely designed multimode interference coupler 9 can efficiently realize the coupling and transmission of spatial light, providing a strong guarantee for the overall performance improvement of the photon integrated spatial optical receiver 10.

[0056] Preferably, the thickness of the substrate layer 7 of the inversely designed multimode interference coupler 9 is determined according to the following formula: in, is the thickness of the substrate layer 7, is the wavelength of incident light, is the refractive index of the material used for the substrate layer 7, is the number of cycles.

[0057] In the fields of optical communications and photonic integration, precise design and parameter determination play a crucial role in device performance. In a specific embodiment, the thickness of substrate layer 7 of inverse-designed multimode interference coupler 9 is determined according to a precise formula derived from strict optical principles and practical application requirements. This formula ensures that inverse-designed multimode interference coupler 9 can operate efficiently and stably.

[0058] Specifically, the thickness of the substrate layer 7 is It is calculated by the following formula: in, represents the thickness of substrate layer 7, a parameter that requires precise determination. This thickness directly affects the propagation characteristics of light in substrate layer 7, including phase shifts and interference effects. A suitable thickness ensures that optical signals propagate and interfere as expected in substrate layer 7, thereby achieving optimal performance of the inverse-designed multimode interference coupler 9.

[0059] The wavelength of the incident light is a fundamental property of light, and different applications may utilize light of different wavelengths. In optical communication systems, common wavelengths include 850nm, 1310nm, and 1550nm. Varying wavelengths of incident light can cause variations in the propagation characteristics of light in substrate layer 7. Therefore, the specific wavelength of the incident light must be considered when determining the thickness of substrate layer 7.

[0060] is the number of cycles, which is an integer and is usually determined based on specific design requirements and optical performance requirements. The selection will affect the thickness of the substrate layer 7 and the interference effect of light therein. In actual design, the inventor will determine the appropriate number of cycles through theoretical calculation and simulation analysis based on the specific application scenario and performance indicators of the inverse design multimode interference coupler 9. .

[0061] This formula allows us to accurately calculate the thickness of substrate layer 7 based on the wavelength of the incident light, the refractive index of the material used in substrate layer 7, and the predetermined number of periods. This precise design method enables the inverse-designed multimode interference coupler 9 to achieve efficient coupling and processing of optical signals under various operating conditions, providing a strong guarantee for improving the performance of optical communications and photonic integrated systems.

[0062] In summary, through precise calculations and advanced manufacturing processes, the thickness of substrate layer 7 of the inverse-designed multimode interference coupler 9 can be precisely controlled, providing a solid foundation for high-performance operation of the entire device. This approach, based on scientific principles and precise design, will help promote the continued development and advancement of optical communications and photonic integration technologies.

[0063] Preferably, the metasurface dynamic wavefront correction layer 8 is a superlens.

[0064] As optical communication technology continues to advance, various design options exist for the metasurface dynamic wavefront correction layer 8, a key component of the photonic integrated spatial optical receiver 10. However, after extensive theoretical research, experimental verification, and practical application considerations, the metasurface dynamic wavefront correction layer 8 is preferably designed as a metalens.

[0065] As a new type of optical element, the metalens possesses unique advantages that are difficult to match with traditional lenses, making it an ideal choice for the metasurface dynamic wavefront correction layer 8. Compared to traditional glass microlenses, the structure of the metalens exhibits significant differences. Traditional glass microlenses rely on their curved surface shape to refract and focus light, while the metalens, based on the principles of metasurfaces, flexibly manipulates the light field by precisely controlling the geometric parameters and spatial position of the surface micro-nanostructures. This micro-nanostructure-based design gives the metalens a flat structure, which not only facilitates the high integration of optical devices but also effectively reduces the volume and weight of the entire optical system, making it particularly important in the space-constrained photon-integrated spatial light receiver 10.

[0066] In terms of optical performance, the metalens exhibits exceptional properties. It exhibits no axial chromatic aberration, meaning that light of different wavelengths can be focused at the same location when passing through the metalens, avoiding image blur or signal distortion caused by chromatic aberration. In optical communication systems, optical signals often contain light of multiple wavelengths. This characteristic of the metalens ensures that optical signals of each wavelength can be accurately focused and processed, greatly improving the transmission quality of the optical signal and the stability of the system.

[0067] Metalenses also offer the advantage of high design freedom. The diversity and controllability of their surface micro-nanostructures allow designers to flexibly tailor the optical functionality of the metalens to specific application requirements. In the photonic integrated spatial light receiver 10, the metalens can precisely adjust light focusing and wavefront correction based on the incident angle, wavelength, and phase of spatial light. By varying parameters such as the period, height, and radius of the micro-nanostructures, the metalens can achieve fine-grained control of the light field, thereby better adapting to complex and changing optical signal environments.

[0068] When the metasurface dynamic wavefront correction layer 8 adopts a superlens design, it can give full play to its own advantages in the photon-integrated spatial light receiver 10. The superlens can efficiently focus spatial light into a focused light spot, providing high-quality input for subsequent optical signal processing. Its flexible control ability of the light field enables it to dynamically correct spatial light with wavefront distortion caused by factors such as atmospheric turbulence, ensuring the quality and stability of the focused light spot. Through precise micro-nanostructure design, the superlens can achieve multi-dimensional dynamic adaptation of the light wavefront phase, polarization state, and incident angle, and work in conjunction with other components such as the inverse-designed multimode interference coupler 9 to jointly enhance the photon-integrated spatial light receiver 10's processing capability for complex optical signals, thereby effectively improving the communication quality and reliability of the optical communication system.

[0069] The present invention also provides an optical implementation method of a photon-integrated spatial light receiver 10, which is used for the photon-integrated spatial light receiver 10. The method includes: The spatial light is received by the metasurface dynamic wavefront correction layer 8 and is focused into a focused light spot; The focused light spot is input as the input light field to the inverse-designed multimode interference coupler 9 through the metasurface dynamic wavefront correction layer 8; By inversely designing a multimode interference coupler 9, the orthogonal modes in the input optical field are effectively demultiplexed into multiple independent optical outputs. Each optical field is then converted into a waveguide fundamental mode and output via the corresponding waveguide channel 4. Specifically, this method can be applied to a photon-integrated spatial optical receiver 10, aiming to fully leverage the receiver's performance advantages, achieve efficient processing and conversion of spatial light, and thereby improve the overall quality and efficiency of optical communication systems. The following describes the various steps of this optical implementation method in detail.

[0070] Step 1: Receive and focus spatial light At the initial stage of the entire optical processing flow, the metasurface dynamic wavefront correction layer 8 performs a critical task: receiving spatial light and focusing it into a focused spot. Through precise design and optimization, the metasurface dynamic wavefront correction layer 8 is able to focus the complex spatial light field into a focused spot with highly concentrated energy. This focused spot not only contains the information carried by the spatial light but also has excellent optical quality, providing excellent input conditions for subsequent optical signal processing.

[0071] Step 2: Input the focused spot into the coupler After successfully focusing the spatial light into a focused spot, the metasurface dynamic wavefront correction layer 8 uses this focused spot as the input light field and accurately inputs it into the inverse-designed multimode interference coupler 9. This step requires ensuring that the focused spot can accurately reach the appropriate position of the inverse-designed multimode interference coupler 9 to ensure that subsequent light field conversion and processing can proceed smoothly.

[0072] To achieve this goal, during the design and fabrication of the photonic integrated spatial optical receiver 10, the relative positions and optical parameters of the metasurface dynamic wavefront correction layer 8 and the inverse-designed multimode interference coupler 9 need to be precisely calibrated. The focal position of the metasurface dynamic wavefront correction layer 8 needs to be precisely aligned with the input port of the inverse-designed multimode interference coupler 9 to ensure that the focused light spot can be input into the inverse-designed multimode interference coupler 9 in an optimal state.

[0073] Step 3: Convert and output multi-channel light fields After receiving the input light field, the inverse-designed multimode interference coupler 9 will play its core function, effectively demultiplexing the orthogonal modes in the input light field into multiple independent light field outputs, and further converting each light field into a waveguide fundamental mode, which is output separately through the corresponding waveguide channel 4. Inside the inverse-designed multimode interference coupler 9, the light field undergoes a complex interference and diffraction process. Through carefully designed micro-nano structures, the inverse-designed multimode interference coupler 9 is able to demultiplex the different modes of light in the input light field and convert them into the corresponding waveguide fundamental modes. These mode lights propagate in the waveguide in the form of fundamental modes, with low loss and high stability.

[0074] After conversion, the inverse-designed multimode interference coupler 9 transmits the multiple optical field outputs through their corresponding waveguide channels 4. Waveguide channels 4 are structures specifically designed to transmit optical signals, guiding light along specific paths and minimizing light leakage and scattering. Each waveguide channel 4 corresponds to an output port in the inverse-designed multimode interference coupler 9, ensuring that each optical field output is accurately transmitted to subsequent optical components or processing units.

[0075] Through the above three steps, the optical implementation method of the photonic integrated spatial light receiver 10 of the present invention can effectively convert complex spatial light into multi-path stable waveguide fundamental mode light field output, providing high-quality optical signal input for the optical communication system, and helping to improve the performance and reliability of the optical communication system.

[0076] Preferably, the input light field is converted into a multi-path light field output by inversely designing the multimode interference coupler 9, and specifically includes: The input light field is decomposed into multiple modes by inversely designing the multimode interference coupler 9, and the different modes of light are separated into corresponding waveguide channels 4; wherein the multiple waveguide channels 4 correspond to different modes respectively.

[0077] Specifically, when the focused light spot enters the inverse-designed multimode interference coupler 9 as the input light field, the inverse-designed multimode interference coupler 9 first uses its special micro-nanostructure constructed based on advanced inverse design algorithms to perform in-depth mode decomposition of the input light field. During the propagation of light, the input light field often contains a variety of different mode lights, which differ in terms of light phase, amplitude, polarization state, and propagation direction. The micro-nanostructure of the inverse-designed multimode interference coupler 9 can accurately perceive these differences and, based on the designed optical principles and algorithms, decompose the mixed input light field into different modes.

[0078] This mode decomposition process is like a delicate "optical sorting" operation. The micro-nanostructures within the inverse-designed multimode interference coupler 9 act like tiny, precise "optical filters," specifically manipulating the light field based on the characteristics of different light modes. As the light field propagates through these micro-nanostructures, different modes of light experience varying degrees of interference and diffraction, gradually separating them spatially.

[0079] After completing mode decomposition to generate multiple light modes, the inverse-engineered multimode interference coupler 9 must accurately guide these separated light modes into their corresponding waveguide channels 4. This process requires highly precise optical alignment and coupling between the inverse-engineered multimode interference coupler 9 and the waveguide channels 4. Each waveguide channel 4 is designed to efficiently propagate only specific light modes, like dedicated channels for different "optical couriers."

[0080] To achieve precise matching of the light modes with the waveguide channel 4, the inventors utilized advanced micro-nanofabrication techniques and optical simulation software during the design and fabrication of the inverse-engineered multimode interference coupler 9. By precisely controlling the size, shape, and spacing of the micro-nanostructures, as well as the geometric parameters and position of the waveguide channel 4, they ensured that each light mode could enter its corresponding waveguide channel 4 with optimal coupling efficiency. For example, for a particular light mode, its propagation path within the inverse-engineered multimode interference coupler 9 was precisely designed so that upon reaching the waveguide channel 4, the distribution of the light field was optimally matched to the fundamental mode of the waveguide channel 4, thereby achieving the lowest transmission loss and the highest transmission efficiency.

[0081] Preferably, the orthogonal modes in the input light field are effectively demultiplexed into multiple independent light field outputs by inversely designing the multimode interference coupler 9, specifically comprising: performing mode decomposition of the input light field by inversely designing the multimode interference coupler 9 to generate multiple mode lights, and separating the different mode lights into corresponding waveguide channels 4; wherein the multiple waveguide channels 4 correspond to different modes respectively.

[0082] When the focused light spot enters the inverse-designed multimode interference coupler 9 as the input light field, the spatial optical coupler 5 comes into play first. Due to its special micro-nano structure, it is able to decompose the input light field into modes. When light propagates in such a complex micro-nano structure, interference and diffraction phenomena will occur. Different orthogonal mode lights have different propagation characteristics in these micro-nano structures, such as differences in propagation speed, phase change, etc. By cleverly designing the parameters of the micro-nano structure, light of different modes is gradually separated during the propagation process, thereby generating multi-path mode light. To put it in another way, it is like taking mixed threads of different colors and using a special tool to classify them according to color and separate them into multiple separate threads. Here, threads of different colors represent different mode lights, and the spatial optical coupler 5 is that special tool.

[0083] Multiple waveguide channels 4 correspond to different modes, which is the key to achieving mode separation. These waveguide channels 4 are like "highways" specially prepared for different modes of light, and each mode of light has its corresponding "dedicated road".

[0084] The multiple light modes generated by mode decomposition are guided by the internal structure of the inverse-designed multimode interference coupler 9 into their corresponding waveguide channels 4. In this process, the micro-nanostructures guide the propagation of light. This is similar to a complex traffic hub with multiple lanes. Vehicles (light modes) enter their corresponding lanes (waveguide channels) based on different indicators (guided by the micro-nanostructures), thus achieving separation of the different light modes. This separation ensures that each light mode can be transmitted independently, preventing mutual interference between different light modes. This ensures the subsequent conversion of each light field into the waveguide fundamental mode and the stable transmission of the optical signal.

[0085] By inversely designing the multimode interference coupler 9 to decompose and separate the input light field, the complex input light field can be split into multiple independent modes according to orthogonal modes, and each is fed into the corresponding waveguide channel 4. This effectively avoids interference between modes, improves the accuracy and stability of optical signal transmission, and lays a solid foundation for the subsequent efficient conversion of the light field to the waveguide fundamental mode. This greatly optimizes the performance of the photonic integrated spatial optical receiver, enabling optical communication systems to more reliably and efficiently process and transmit optical signals.

[0086] Preferably, each light field is further converted into a waveguide fundamental mode and outputted through the corresponding waveguide channel 4, specifically including: for each mode light, using the mode overlap integral method to achieve the maximum efficiency mode field matching between the input mode and the waveguide fundamental mode in space; based on the convex optimization algorithm, designing a micro-nano structure that meets the high coupling efficiency requirements of multiple mode conversions.

[0087] During the operation of the photonic integrated spatial light receiver 10, converting each light field into a waveguide fundamental mode and outputting it through the corresponding waveguide channel 4 is a key link to ensure stable transmission of the optical signal. This is mainly achieved through two core steps: mode overlap integral and designing micro-nanostructures based on a convex optimization algorithm.

[0088] For each light mode, the mode overlap integral method is a key means of achieving efficient mode field matching. Before entering a waveguide for transmission, the mode of the light mode is not fully aligned with the fundamental mode of the waveguide. The mode overlap integral calculates the degree of spatial overlap between the input light mode and the fundamental mode of the waveguide. Mathematically, by integrating the field distribution functions of the two modes at each point in space, a value reflecting the degree of similarity between the two modes is obtained. In practice, the propagation conditions of the input light mode are adjusted, such as by modifying its phase and amplitude distribution. The input light mode can be imagined as a beam of light with a specific shape and energy distribution, while the fundamental mode of the waveguide is the light form most suitable for stable transmission in the waveguide. The mode overlap integral is like adjusting the shape and energy distribution of the input light to closely match the ideal transmission form in the waveguide. This minimizes energy loss during light transmission in the waveguide, achieving the most efficient mode field matching and improving optical signal transmission efficiency.

[0089] Convex optimization algorithms play a crucial role in designing micro-nanostructures that meet the requirements for multi-mode conversion and high coupling efficiency. Photonic integrated spatial optical receivers must process multiple modes of light, each with different requirements for conversion to the fundamental waveguide mode. Based on a mathematical model, convex optimization algorithms use mode conversion efficiency and micro-nanostructure parameters as optimization objectives and constraints. During the design process, the algorithm continuously adjusts various micro-nanostructure parameters, such as the size, shape, and arrangement of nanopillars. For a simple example, assuming the micro-nanostructure consists of nanopillars, the convex optimization algorithm will try different combinations of nanopillar height, radius, and spacing to find the optimal parameter combination that maximizes the conversion of the maximum number of modes to the fundamental waveguide mode with high coupling efficiency. Micro-nanostructures designed in this way can achieve efficient mode conversion and energy transmission, ensuring stable and efficient transmission of optical signals within complex photonic integrated systems and improving the performance of the entire spatial optical receiver.

[0090] The advantages of using mode overlap integrals and convex optimization algorithms to design micro-nanostructures are significant. Mode overlap integrals precisely adjust the matching degree between the input mode and the fundamental mode of the waveguide, minimizing energy loss during light transmission and improving transmission efficiency. Designing micro-nanostructures based on convex optimization algorithms fully considers multiple mode conversion requirements, finding the optimal parameter combination for efficient mode conversion and energy transmission. This effectively ensures the stable and efficient transmission of optical signals in complex systems, and comprehensively improves the performance of photonic integrated spatial optical receivers.

[0091] 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 photon-integrated spatial light receiver, characterized in that: The photon-integrated spatial light receiver comprises a metasurface dynamic wavefront correction layer and an inverse-designed multimode interference coupler, wherein the inverse-designed multimode interference coupler forms a mode demultiplexing conversion channel; The metasurface dynamic wavefront correction layer focuses the spatial light into a focused light spot, and the focused light spot serves as the input light field of the inverse-designed multimode interference coupler; The inversely designed multimode interference coupler effectively demultiplexes the orthogonal modes in the input light field into multiple independent light field outputs, and further converts each light field into a waveguide fundamental mode and outputs them respectively through the corresponding waveguide channels.

2. The photon-integrated spatial light receiver according to claim 1, wherein: The focus of the metasurface dynamic wavefront correction layer coincides with the center of the inverse-designed multimode interference coupler, so that the metasurface dynamic wavefront correction layer inputs the focused light spot into the center of the inverse-designed multimode interference coupler.

3. The photon-integrated spatial light receiver according to claim 2, wherein: The metasurface dynamic wavefront correction layer is composed of a two-dimensional nanocolumn array and a base material. The two-dimensional nanocolumn array is composed of a plurality of nanocolumns with subwavelength scales, and the two-dimensional nanocolumn array is fixed on the base material.

4. The photon-integrated spatial light receiver according to claim 3, wherein: The heights of the plurality of nanopillars in the two-dimensional nanopillar array are the same; When the height is determined, the nanorods are arranged in a specific phase, and the phase of the nanorods at the corresponding position is determined according to the following formula: in, Arrange the corresponding positions The phase of the nanopillars on is the target focal length of the metasurface dynamic wavefront correction layer, is the distance between the edge of the incident light of the metasurface dynamic wavefront correction layer and the optical axis of the metasurface dynamic wavefront correction layer, is the vacuum wavelength, The refractive index of the material used for the nanopillars of the metasurface dynamic wavefront correction layer, ∈(0, the number of rows in the two-dimensional nanopillar array - 1) and ∈ (0, the number of columns in the two-dimensional nanocolumn array - 1) corresponds to the position of the nanocolumns in the two-dimensional nanocolumn array.

5. The photon-integrated spatial light receiver according to claim 2, wherein: The inverse-designed multimode interference coupler is a three-layer vertical structure consisting of a spatial optical coupler, a substrate layer, and a metal reflective layer. The spatial optical coupler is arranged on one side of the substrate layer, and the metal reflective layer is deposited on the other side of the substrate layer by a sputtering process.

6. The photon-integrated spatial light receiver according to claim 5, characterized in that: The thickness of the substrate layer of the inverse-designed multimode interference coupler is determined according to the following formula: in, is the thickness of the substrate layer, is the wavelength of incident light, is the refractive index of the material used for the substrate layer, is the number of cycles.

7. The photon-integrated spatial light receiver according to claim 4, characterized in that: The metasurface dynamic wavefront correction layer is a metalens.

8. A method for optically implementing a photon-integrated spatial light receiver, characterized in that: For the photon-integrated spatial light receiver according to any one of claims 1 to 7, the method comprises: receiving spatial light through the metasurface dynamic wavefront correction layer and focusing the spatial light into a focused light spot; Inputting the focused light spot as an input light field into an inverse-designed multimode interference coupler through the metasurface dynamic wavefront correction layer; The inversely designed multimode interference coupler effectively demultiplexes the orthogonal modes in the input light field into multiple independent light field outputs, and further converts each light field into a waveguide fundamental mode and outputs them respectively through the corresponding waveguide channels.

9. The optical implementation method of the photon integrated spatial light receiver according to claim 8, characterized in that: The inversely designed multimode interference coupler is used to effectively demultiplex the orthogonal modes in the input light field into multiple independent light field outputs, and specifically includes: The input light field is subjected to mode decomposition by the inversely designed multimode interference coupler to generate multi-path mode light, and different mode lights are separated into corresponding waveguide channels; wherein the multiple waveguide channels correspond to different modes respectively.

10. The optical implementation method of the photon integrated spatial light receiver according to claim 9, characterized in that: Each optical field is further converted into a waveguide fundamental mode and output through the corresponding waveguide channel, specifically including: For each mode light, the mode overlap integral method is used to achieve the most efficient mode field matching between the input mode and the waveguide fundamental mode in space; based on the convex optimization algorithm, a micro-nanostructure is designed to meet the high coupling efficiency requirements of multiple mode conversions.

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