	US 12,353,802 B1
	Model-based adaptive multi-aperture optical fiber coupling control system and method
Huizhen Yang, Nanjing (CN); Xianshuo Li, Nanjing (CN); Peng Chen, Nanjing (CN); Zhengqing Qi, Nanjing (CN); and Ronggang Zhu, Nanjing (CN)
Assigned to JINLING INSTITUTE OF TECHNOLOGY, Nanjing (CN)
Filed by JINLING INSTITUTE OF TECHNOLOGY, Nanjing (CN)
Filed on Jan. 17, 2025, as Appl. No. 19/026,409.
Application 19/026,409 is a continuation of application No. PCT/CN2024/141700, filed on Dec. 24, 2024.
Claims priority of application No. 202410840767.9 (CN), filed on Jun. 27, 2024.
Int. Cl. G06F 30/18 (2020.01); G06F 111/10 (2020.01)

CPC G06F 30/18 (2020.01) [G06F 2111/10 (2020.01)]

2 Claims

1. A model-based adaptive multi-aperture optical fiber coupling control method, applied to a control system, comprising the following steps:

step 1, initializing parameters of a control algorithm within a controller of the control system, using a fiber coupling efficiency as an objective function of the control algorithm;

step 2, preprocessing;

wherein the preprocessing in the step 2 specifically comprises the following steps: defining a set of basis functions {Z_x,Z_y} for characterizing a wavefront tilt aberration, respectively recording as a tilt in a X direction and a tilt in a Y direction, calculating gradient second-order moments of the basis function Z_xand the basis function Z_yfor x component and y component, inverting, and recording as a gradient inverse matrix P; measuring an influence function E of a coupling lens of the control system, establishing a cross-correlation matrix C_zebetween the coupling lens and the basis functions, and calculating an autocorrelation coupling matrix C_ebetween the influence functions of a driver, and using Equation (1) to obtain a driving signal of the coupling lens v;

where a is a variable scalar value;

step 3, measuring and calculating a sum I_i0of light intensities of N sub-apertures of the control system;

wherein the step 3 is specifically as follows: taking a center of mass corresponding to each sub-aperture as a center, intercepting an image plane of a size M*M, and calculating the sum I_i0of the respective light intensities of the N sub-apertures, where i∈{1, . . . , N};

step 4, adding a voltage perturbation of an X direction basis function with a coefficient a to the N sub-apertures in parallel, and measuring and calculating a sum of respective light intensities of the N sub-apertures; adding a voltage perturbation of a Y direction basis function with the coefficient a again, and measuring and calculating a sum of respective light intensities of the N sub-apertures;

wherein the step 4 is specifically as follows: adding the voltage perturbation of the X direction basis function with the coefficient of a to the N sub-apertures in parallel, and calculating a voltage magnitude according to the Equation (1), intercepting the image plane with the size M*M with the center of mass of each sub-aperture as the center, and calculating the sum I_ixof the respective light intensities of part of image surfaces intercepted by the N sub-apertures; adding the voltage perturbation of the Y direction basis function with the coefficient of a to the N sub-apertures in parallel, and calculating the voltage magnitude according to the Equation (1); intercepting the image plane with the size M*M with the center of mass of each sub-aperture as the center, and calculating the sum I_y, of the respective light intensities of part of the image surfaces intercepted by the N sub-apertures;

step 5, performing a difference operation on the measured sum of the light intensities after perturbations by the N sub-apertures and the sum of the light intensities corresponding to a distorted wavefront;

wherein the step 5 is specifically as follows: performing the difference operation on the measured light intensities (I_ix,I_iy) after perturbations by the N sub-apertures and the sum I_i0of the light intensities of the N sub-apertures corresponding to the distorted wavefront to obtain an N×2-dimensional vector Q:

Q_i={(I_ix,I_iy)−I_i0} i∈{1, . . . N} (2);

where Q_irepresent a light intensity difference of an i-th sub-aperture;

step 6, calculating and obtaining coupler driving signals corresponding to the N sub-apertures by using results of the difference operation; amplifying the coupler driving signals by a amplifier and applying the coupler driving signals to the driver of the coupling lens for each sub-aperture; detecting corrected light spot information with a photoelectric detector, and calculating a system performance evaluation function for a current iteration based on the corrected light spot information;

wherein calculating the driving signals in the step 6 is specifically as follows: obtaining a coupler driving signal V_icorresponding to each of the N sub-apertures by using the following Equation (3), where V is an N-dimensional control signal;

and

step 7, taking a residual wavefront as a wavefront to be corrected, and repeating the steps 3-6 to reach a preset termination condition and complete a correction of the distorted wavefront;

wherein the model-based adaptive multi-aperture optical fiber coupling control method comprises:

generating a surface type opposite to the distorted wavefront through an optical fiber coupler of the control system, superposing the surface type with the distorted wavefront to complete the correction of the distorted wavefront, and thereby controlling an optical fiber end face to find a maximum coupling efficiency point on a back focal plane to improve the fiber coupling efficiency.