Cheng Zhongtao, Yang Jiamiao, 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.
ACS Photonics. 2020 Oct 21;7(10):2871-2877. doi: 10.1021/acsphotonics.0c01154. Epub 2020 Sep 18.
Optical time reversal can focus light through or into scattering media, which raises a new possibility for conquering optical diffusion. Because optical time reversal must be completed within the correlation time of speckles, enhancing the speed of time-reversed optical focusing is important for practical applications. Although employing faster digital devices for time-reversal helps, more efficient methodologies are also desired. Here, we report a single-shot time-reversed optical focusing method to minimize the wavefront measurement time. In our approach, all information requisite for optical time reversal is extracted from a single-shot hologram, and hence no other preconditions or measurements are required. In particular, we demonstrate the first realization of single-shot time-reversed ultrasonically encoded (TRUE) optical focusing into scattering media. By using the minimum amount of measurement, this work breaks the fundamental speed limit of digitally based time reversal for focusing into and through scattering media, and constitutes an important step toward high-speed wavefront shaping applications.
光学时间反转可以使光聚焦通过或进入散射介质，这为克服光扩散带来了新的可能性。由于光学时间反转必须在散斑的相关时间内完成，提高时间反转光学聚焦的速度对于实际应用至关重要。虽然使用更快的数字设备进行时间反转有帮助，但也需要更有效的方法。在此，我们报告一种单次时间反转光学聚焦方法，以尽量减少波前测量时间。在我们的方法中，光学时间反转所需的所有信息都从单次全息图中提取，因此不需要其他前提条件或测量。特别是，我们首次实现了单次时间反转超声编码（TRUE）光学聚焦进入散射介质。通过使用最少的测量量，这项工作打破了基于数字的时间反转聚焦进入和通过散射介质的基本速度限制，并朝着高速波前整形应用迈出了重要一步。
