AI 中文总结
本文针对大气湍流导致自由空间光通信性能下降的问题，提出实时递归优化程序估计随时间演化的大气信道传输矩阵，可提升光耦合效率并降低功率中断概率，适用于经典与量子自由空间光通信。
AI 中文摘要
光波长在自由空间信道中已受到广泛关注，对通信、成像和传感等应用至关重要。其广泛应用得益于带宽提升、安全性增强及能量效率更高等多种优势。但在实际场景中，这些优势因大气湍流的有害效应无法充分发挥。大气湍流由环境中空间和时间快速变化的微小温度与压力波动引发，会导致显著的功率损耗，降低信噪比（SNR），在通信链路中引发严重串扰，并极大限制远程成像系统的分辨率。为解决该问题，本文通过数值模拟和实验，研究了采用实时递归优化程序对随时间演化的大气信道传输矩阵进行重构的方法。研究表明，该估计技术能够跟踪信道的演化，可显著改善与通信相关的性能指标，例如将接收光耦合进单模光纤的效率，同时大幅降低功率中断的概率和持续时间，即使在强湍流环境下亦是如此。研究结果可直接应用于经典和量子领域的自由空间光通信。
英文摘要
Optical wavelengths have received significant attention in free-space channels and are vital for applications in communications, imaging and sensing. Their widespread implementation is motivated by a variety of factors including improved bandwidths, increased security and higher energy efficiency. However, these advantages cannot be fully brought to bear in real-world scenarios due to the deleterious effects of atmospheric turbulence. Induced by small temperature and pressure fluctuations in the environment that vary rapidly in space and time, these effects cause significant power losses which decrease SNR, induce severe crosstalk in communication links, and greatly limit resolution of long-range imaging systems. To overcome this, we numerically and experimentally investigate the reconstruction of the transmission matrix of a time-evolving atmospheric channel with a real-time recursive optimization routine. We demonstrate that this estimation technique is able to keep up with the evolution of the channel and enables a significant improvement of communication-relevant quantities such as the coupling of the received light into a single-mode fiber while notably reducing the probability and duration of power outages, even in strong turbulence. Our results have immediate applications in free-space optical communication in both the classical and quantum regimes.
