Work

ViT-SPGD: vision transformer-driven stochastic parallel gradient descent for WFS-less adaptive optics in FSO communication

Year: 2025

Type: article

Abstract: In free-space optical communication (FSOC) using wavefront-sensor-less (WFS-less) adaptive optics (AO), stochastic parallel gradient descent (SPGD) is commonly used to mitigate the adverse effects of atmospheric turbulence (AT) and correct the wavefront distortions. However, conventional SPGD often converges slowly and is prone to becoming trapped in local optima, especially under severe phase aberrations. In this study, we propose ViT-SPGD, a novel wavefront-correction method that integrates a vision transformer (ViT) with SPGD, to significantly improve wavefront correction performance. Specifically, the ViT predicts a deterministic, high-confidence gradient direction while SPGD provides stochastic gradient perturbations. By adaptively fusing the two directions, the hybrid update leverages ViT's learned before accelerate convergence while preserving SPGD's stochastic exploration whenever the ViT guidance is uncertain. We first detail the ViT-SPGD design and fusion mechanism, then validate its performance by comparing it with the original SPGD and two established variants, AdamSPGD and NSPGD. Simulation results, including the system-level dynamic simulations, show that ViT-SPGD substantially accelerates convergence and improves robustness in phase distortion correction. By combining deep learning techniques (i.e., ViT), with traditional iterative optimization (i.e., SPGD), ViT-SPGD provides a practical blueprint for intelligent, high-performance AO and helps pave the way for more robust FSOC operation in atmospheric conditions.

Source: Optics Express

DOI: 10.1364/oe.581667

Authors: Zhaokun Li, Hua Ming, Xiongchao Liu, Jing Jiang, Tao Shang

Institution: Xidian University

Language: English

Topic: Adaptive optics and wavefront sensing

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,270

Funders: National Natural Science Foundation of China, Fundamental Research Funds for the Central Universities