Yu Yeh-Wei, Hou Tsung-Yi, Yang Tsung-Hsun, Sun Ching-Cherng
Department of Optics and Photonics, National Central University, Chung-Li, 32001, Taiwan.
Department of Electrophysics, National Yang Ming Chiao Tung University, Hsin-Chu, 30010, Taiwan.
Sci Rep. 2022 Jun 8;12(1):9471. doi: 10.1038/s41598-022-13578-3.
In this paper, we propose and demonstrate a novel interferometer and signal process to retrieve two-dimensional signals with multilevel phases. The interferometer is based on a shearing interferometry with double-frequency grating, and phase-shifting interferometry is derived as a built-in function of the lateral displacement of the grating. The interferometer not only retrieves the multilevel phase signals but also eliminates slow-varying phase errors wherever they occur. Owing to the common path algorithm, the new interferometer is more robust in dynamic circumstances for optical testing and data processing. We propose a pre-integral signal process for two-dimensional (2D) data processing to prevent post-phase-integral due to shearing interferometry. The simulation and experiment showed that the proposed interferometer with a pre-integral process has various advantages in signal processing for multilevel phase retrieval, and will be useful for higher data rates in optical data storage and free-space communication.
在本文中，我们提出并演示了一种新颖的干涉仪及信号处理方法，用于检索具有多级相位的二维信号。该干涉仪基于带有双频光栅的剪切干涉测量法，相移干涉测量法是作为光栅横向位移的内置功能推导得出的。该干涉仪不仅能检索多级相位信号，还能消除任何位置出现的慢变相位误差。由于采用了共光路算法，这种新型干涉仪在光学测试和数据处理的动态环境中更具鲁棒性。我们提出了一种用于二维（2D）数据处理的预积分信号处理方法，以防止因剪切干涉测量法导致的后相位积分。仿真和实验表明，所提出的带有预积分处理的干涉仪在多级相位检索的信号处理方面具有多种优势，并且将有助于提高光学数据存储和自由空间通信中的数据速率。
