六端口光学混频器的相位补偿研究

Reseach on phase compensation of a six-port optical hybrid

设计了一个由可调半波片和集成偏振敏感光学元件组成的六端口光学混频器。通过在本征光通道中引入可调节半波片,使六端口光学混频器可实现良好的相位不平衡误差补偿。给出了混频器的工作原理和相位不平衡误差的补偿理论,并研究了其输出特性。结果表明,所设计的六端口光学混频器可实现较宽范围的相位不平衡补偿,并且经补偿后的正交信号相位不平衡量小于0.5o,应用在同差激光多普勒测振系统中实现了nm级振动信息的检测。

A six-port optical hybrid is designed using an integrated polarization sensitive device and an adjustable half- wave plate （I/W）. By carefully revolving the HW in the local beam path, the imbalanced phase errors between output mixed signals are well corrected. Details, both in phase compensation principle and experiments, on the hybrid, are given. The output characteristics are studied. Results show that the hybrid realizes compensation for large-range imbalanced phase errors and generates in-phase and quadratic signals with imbalanced phase errors less than 0. 5°. This optical hybrid is successfully applied in a homodyne Laser Dooppler Vihrometer for vibration detection.