中国激光, 2019, 46 (9): 0904005, 网络出版: 2019-09-10
光纤四通道双平衡外差相位检测实验研究 下载: 984次
Fiber-Optic Four-Channel Dual-Balanced Heterodyne Phase Detection
测量 外差检测 四通道双平衡探测 电光调制 相位检测 measurement heterodyne detection four-channel dual-balanced detection electro-optic modulation phase detection
摘要
为实现高灵敏度的外差相位检测,提出了一种基于光外差检测原理的光纤四通道双平衡外差相位检测方法。搭建光纤四通道双平衡外差检测光路,采用1/4波片作为相位检测样品,验证分析了光纤四通道双平衡外差相位检测的性能。分析了外差检测中信号调制频率对相位测量结果的影响,结果表明受限于光电接收器件的响应带宽,过高或过低的调制频率均不能有效检测到相位信息。在实验中,最优的信号调制频率范围为 500.5~1550.5 kHz,实际测得的相位均方根为89.1°,标准差为0.3°。在此基础上,分析了双平衡外差干涉中光纤分束比以及耦合透镜的有效接收口径效应对相位检测的影响。当光纤分束比接近1∶1时,得到了较高信噪比下更加精确的检测结果;通过改变耦合透镜的发射角,验证了有效接收口径对接收信号灵敏度的实际影响。
Abstract
This study proposes a fiber-optic four-channel dual-balanced heterodyne phase detection method based on optical heterodyne detection principle to realize high-sensitivity heterodyne phase detection. A fiber-optic four-channel dual-balanced heterodyne detection optical path is experimentally established, and a quarter-wave plate is used as a phase detection sample to verify the detection performance. Further, the influence of the signal modulation frequency on the phase measurement result in heterodyne detection is analyzed. Results reveal that the phase information cannot be effectively detected by too high or too low modulation frequency due to the limitation of the response bandwidth of the photodetector. Fiber splitting ratio in double-balanced heterodyne interference and the effect of the effective receiving aperture of the coupling lens on phase detection are analyzed based on the optimal signal modulation frequency of 500.5-1550.5 kHz and the actual measured phase root-mean-square of 89.1° with a standard deviation of 0.3°. When the fiber splitting ratio is approximately 1∶1, a more accurate detection result with a higher signal-to-noise ratio is obtained. The actual influence of the effective receiving aperture on the sensitivity of the received signal is verified by varying the emission angle of the coupling lens.
施剑波, 张娟, 刘德安. 光纤四通道双平衡外差相位检测实验研究[J]. 中国激光, 2019, 46(9): 0904005. Shi Jianbo, Zhang Juan, Liu Dean. Fiber-Optic Four-Channel Dual-Balanced Heterodyne Phase Detection[J]. Chinese Journal of Lasers, 2019, 46(9): 0904005.