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CN-122021342-A - Multi-plane device optimization design method based on polygon

CN122021342ACN 122021342 ACN122021342 ACN 122021342ACN-122021342-A

Abstract

The invention relates to an optimal design method of a multi-plane device based on a polygon, which comprises the following steps of S1, determining parameters based on the polygon MPLC device, S2, constructing a topology-mode coupling model, determining a phase compensation amount, S3, generating an initial phase mask by combining phase distribution characteristics of a target mode according to the phase compensation amount calculated in the step S2, S4, outputting optimized phase mask parameters based on a genetic optimization algorithm, S5, simulating and verifying, namely, constructing simulation models of different topological structures, inputting the optimized phase mask parameters, simulating a mode evolution process, and analyzing whether a performance threshold meets requirements. The method solves the problems that the traditional algorithm ignores the influence of the topological structure and has poor universality of the phase mask, and realizes the accurate design of different polygonal devices, thereby effectively reducing the loss and improving the shaping effect.

Inventors

  • LI CHAOHUI
  • Shi Yuetong
  • Wen Zhanhong

Assignees

  • 中山大学

Dates

Publication Date
20260512
Application Date
20260407

Claims (10)

  1. 1. The optimized design method of the multi-plane device based on the polygon is characterized by comprising the following steps: S1, determining parameters based on a polygon MPLC device, wherein the parameters comprise a topological structure parameter, a target transmission mode and a performance threshold, the topological structure parameter comprises the number N of faces of the polygon, an included angle theta of adjacent phase faces and a distance d between the adjacent phase faces, and the performance threshold comprises an insertion loss IL and a modal purity factor P; S2, constructing a topology-modal coupling model, and determining a phase compensation amount: Based on the geometrical optics principle, calculating a modal evolution path of the light beam in the target topological structure, and determining model parameters including reflection times, incidence angles of all phase surfaces and total optical path; establishing a topology-modal coupling model: wherein Representing the total phase accumulation amount, The wave number is represented by a number of waves, , Is the working wavelength; determining the phase compensation amount to be provided by the phase mask according to the modal evolution path, the model parameters and the topology-modal coupling model; S3, determining an initial phase mask, namely generating the initial phase mask according to the phase compensation quantity calculated in the step S2 and combining the phase distribution characteristics of the target mode; s4, outputting optimized phase mask parameters based on a genetic optimization algorithm, wherein the fitness function in the genetic optimization algorithm is expressed as: , 、 、 Is a weight coefficient; S5, simulation verification, namely building simulation models of different topological structures, inputting optimized phase mask parameters, simulating a modal evolution process, analyzing whether a performance threshold meets requirements, and if not, returning to the step S2, and adjusting model parameters until the target design requirements are met.
  2. 2. The method for optimizing design of a polygon-based multi-planar device according to claim 1, wherein the step of performing phase plane etching by using a topology partition and a mode-specific etching mode based on differences of mode evolution paths of different polygon topologies comprises: according to the incidence angle and the light spot distribution of the light beam on each phase surface and combining topological parameters, the topological parameters comprise an included angle and a distance between the phase surfaces, the phase surfaces are divided into a core regulation area and a topology adaptation area, wherein the core regulation area etches a target modal phase pattern, and the topology adaptation area etches a phase compensation amount matched with a topological structure, so that modal conversion efficiency and stability of MPLC devices of different topological structures are ensured.
  3. 3. The method for optimizing design of polygon-based multi-planar device of claim 2, wherein for differences in loss sources of different polygonal topologies, a topology differential compensation strategy is used to differentially compensate for different topologies to reduce loss.
  4. 4. The optimal design method for a polygonal-based multi-planar device according to claim 3, wherein for a quadrangular MPLC device, a reflection phase plane is divided into an LG mode core area and a right angle adaptation area according to the number of reflection times, wherein the LG mode core area etches a target mode phase pattern, and the right angle adaptation area etches a phase compensation amount to offset a phase jump caused by a 90 DEG included angle; etching anti-reflection texture on transmission phase surface, and texture period ) Depth, depth , Is refractive index.
  5. 5. The method for optimizing design of polygon-based multi-planar device as set forth in claim 3, wherein for a pentagonal MPLC device, the reflection phase plane is divided into an LG01 mode core region, an LG10 mode core region and a 108 ° angle adaptation region according to the number of reflection times, the LG01 mode core region and the LG10 mode core region respectively etch corresponding target mode phase patterns, the 108 ° angle adaptation region etch phase compensation amounts, and an anti-reflection etching region, a texture period are set at the edges of each phase plane So as to reduce the edge reflection loss, Is refractive index; etching anti-reflection texture on transmission phase surface, and texture period ) Depth, depth And simultaneously, superposing the phase correction quantity with a preset value to balance the transmission loss and the reflection loss.
  6. 6. The optimal design method of the polygonal-based multi-plane device according to claim 3 is characterized in that for a heptagon MPLC device, a reflection phase surface is divided into 4 multi-mode core areas and a long optical path adaptation area according to reflection times, the 4 multi-mode core areas are subjected to multi-mode parallel etching, 2-8 target modes of transmission can be adapted, and the long optical path adaptation area etches a phase compensation amount to offset phase attenuation caused by a long optical path; etching anti-reflection texture on transmission phase surface, and texture period ) Depth, depth And meanwhile, the loss suppression phase pattern is added in the long optical path adaptation area so as to reduce the reflection accumulated loss.
  7. 7. The method for optimizing design of a polygon-based multi-planar device according to any one of claims 1 to 6, wherein the environmental-modal drift correlation models of different topologies are built based on the difference of environmental sensitivities of different polygonal topologies, so as to dynamically adjust environmental parameters according to different topologies, wherein the environmental-modal drift correlation models of different topologies are expressed as: In which, in the process, In order for the temperature to change, For the purpose of the vibration displacement, As the amount of phase shift, For the temperature correction coefficient(s), Is a displacement correction coefficient.
  8. 8. The optimal design method of the polygonal-based multi-plane device according to claim 7, wherein the polygonal-based MPLC device comprises a polygonal glass block, a transmission phase surface and a reflection phase surface are etched on each surface of the polygonal glass block according to design requirements, and a micro temperature sensor for collecting the temperature of the polygonal glass block, a vibration sensor for collecting vibration displacement of the polygonal glass block and a piezoelectric ceramic fine adjustment unit for adjusting the position of the phase surface are integrated on the edge of the polygonal glass block.
  9. 9. The method of optimizing design of a polygon-based multi-planar device of claim 8, wherein for a quadrilateral MPLC device, in an environment-modal drift correlation model, ° C , For pentagonal MPLC devices, C in the environment-modal drift correlation model , For heptagon MPLC devices, in the ambient-modal drift correlation model, ° C , 。
  10. 10. The optimization design method of the polygon-based multi-plane device according to claim 9 is characterized in that temperature and vibration displacement of a polygon glass block are collected in real time through a temperature sensor and a vibration sensor, corresponding environment-modal drift correlation models are called according to different topological structures, phase drift is calculated, for a quadrilateral MPLC device, light path offset caused by vibration displacement is compensated through adjustment of the position of a phase surface, for a pentagonal MPLC device, the position of the phase surface and phase mask equivalent phase are adjusted synchronously, influences of temperature and vibration are balanced, for a heptagon MPLC device, temperature phase drift under a long light path is compensated through adjustment of the phase mask equivalent phase and adjustment of the angle of the phase surface.

Description

Multi-plane device optimization design method based on polygon Technical Field The application relates to the technical field of multi-plane light conversion, in particular to an optimal design method of a multi-plane device based on polygons. Background The multi-plane multiplexing and demultiplexing device is based on multi-plane optical conversion technology (MPLC), and has the core function of multiplexing (combining) and demultiplexing (separating) multiple independent optical signal modes in a Mode Division Multiplexing (MDM) system. In the multiplexing process, the multi-optical signals are integrated into a single optical fiber for transmission, in the demultiplexing process, the signals are separated back to the original independent mode, the multi-transmission mode of the few-mode optical fiber can be fully utilized, the transmission capacity of the single optical fiber is obviously improved, and the multi-optical fiber has the characteristics of strong reconfigurability, low insertion loss and low crosstalk, and is a key component of a modern high-bandwidth communication network. The existing multi-plane optical conversion technology is mainly divided into a transmission type multi-plane multiplexer and a reflection type multi-plane multiplexer. (1) The transmission type multi-plane multiplexer is characterized in that signals directly pass through the multiplexer for transmission, and the multiplexing transmission of the multi-signals on different planes (such as different frequencies and time slices) can be realized by adopting a microwave transmission technology, so that the transmission type multi-plane multiplexer is widely applied to the fields of satellite communication, radar systems and wireless communication. However, the signal energy loss is increased due to multiple transmissions, the cleanliness and the angle accuracy of the transmission surface have great influence on performance, the manufacture and the maintenance are complex, and extra crosstalk is easy to introduce. (2) The reflective multi-plane multiplexer integrates multiple optical signals by utilizing the reflection principle of light, comprises a reflecting mirror or a special optical film coating, can guide different input ports or wavelength optical signals to the same output optical fiber through precise angle reflection, has flexible optical path design and strong wavelength selectivity, and is suitable for high-precision optical path control scenes such as Dense Wavelength Division Multiplexing (DWDM) systems and the like. The light is reflected and shaped back and forth between the phase plate and the reflecting mirror, the phase is processed on a single phase plate, the increase of the phase is required to increase the reflection times, the loss is increased, the shaping effect is affected when the reflection times are too small, the angles and the intervals of the reflecting mirror and the phase affect the mode output, the stability after the debugging is required to be additionally reinforced, the cleanliness and the angle precision of the reflecting surface have great influence on the performance, the manufacturing and the maintenance are complex, and the extra crosstalk is easy to be introduced. Disclosure of Invention The invention aims to overcome the defect that the loss and the shaping effect of a reflective multi-plane multiplexer in the prior art are difficult to balance, and provides an optimal design method of a multi-plane device based on a polygon, which effectively reduces the loss and improves the shaping effect. In order to solve the technical problems, the invention adopts the following technical scheme: The method for optimally designing the multi-plane device based on the polygon comprises the following steps: S1, determining parameters based on a polygon MPLC device, wherein the parameters comprise a topological structure parameter, a target transmission mode and a performance threshold, the topological structure parameter comprises the number N of faces of the polygon, an included angle theta of adjacent phase faces and a distance d between the adjacent phase faces, and the performance threshold comprises an insertion loss IL and a modal purity factor P; S2, constructing a topology-modal coupling model, and determining a phase compensation amount: Based on the geometrical optics principle, calculating a modal evolution path of the light beam in the target topological structure, and determining model parameters including reflection times, incidence angles of all phase surfaces and total optical path; establishing a topology-modal coupling model: wherein Representing the total phase accumulation amount,The wave number is represented by a number of waves,,Is the working wavelength; determining the phase compensation amount to be provided by the phase mask according to the modal evolution path, the model parameters and the topology-modal coupling model; S3, determining an initial phase mask, name