Cheng Zhongtao, Li Chengmingyue, Khadria Anjul, Zhang Yide, Wang Lihong V
Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, Department of Electrical Engineering, California Institute of Technology, Pasadena, California 91125, USA.
Nat Photonics. 2023 Apr;17(4):299-305. doi: 10.1038/s41566-022-01142-4. Epub 2023 Jan 23.
Wavefront shaping (WFS) is emerging as a promising tool for controlling and focusing light in complex scattering media. The shaping system's speed, the energy gain of the corrected wavefronts, and the control degrees of freedom (DOF) are the most important metrics for WFS, especially for highly scattering and dynamic samples. Despite recent advances, current methods suffer from trade-offs that limit satisfactory performance to only one or two of these metrics. Here, we report a WFS technique that simultaneously achieves high speed, high energy gain, and high control DOF. By combining photorefractive crystal-based analog optical phase conjugation (AOPC) and stimulated emission light amplification, our technique achieves an energy gain approaching unity, more than three orders of magnitude larger than conventional AOPC. The response time of ~10 s with about 10 control modes corresponds to an average mode time of about 0.01 ns/mode, which is more than 50 times lower than some of the fastest WFS systems to date. We anticipate that this technique will be instrumental in overcoming the optical diffusion limit in photonics and translate WFS techniques to real-world applications.
波前整形（WFS）正在成为一种用于在复杂散射介质中控制和聚焦光的有前途的工具。整形系统的速度、校正波前的能量增益以及控制自由度（DOF）是WFS最重要的指标，特别是对于高散射和动态样本。尽管最近取得了进展，但目前的方法存在权衡，只能将令人满意的性能限制在这些指标中的一两个上。在这里，我们报告了一种同时实现高速、高能量增益和高控制自由度的WFS技术。通过结合基于光折变晶体的模拟光学相位共轭（AOPC）和受激发射光放大，我们的技术实现了接近单位的能量增益，比传统AOPC大三个数量级以上。约10 s的响应时间和约10个控制模式对应于约0.01 ns/模式的平均模式时间，这比一些迄今为止最快的WFS系统低50倍以上。我们预计这项技术将有助于克服光子学中的光学扩散极限，并将WFS技术转化为实际应用。
