激光多普勒测速光纤光路

Fiber optical path for laser Doppler velocity measurement

为了解决全光纤激光多普勒零差检测光路存在的光能量损耗大、干涉图对比度低、信噪比低等问题,比较了3种全光纤激光多普勒零差检测光路。分析并计算了3种光路中各光纤无源器件的光功率总损耗,设计了3种光路的对比性实验,采用光功率计和插回损仪实测了3种光路光的光功率;观测3种光路光电探测器输出的干涉波形,并且计算了干涉图对比度。结果表明,分析计算结果和实验实测结果吻合,光路中光能量损耗越低,输出的多普勒信号幅值越大,信号信噪比就越高,对比度越高。

In order to solve the all fiber laser doppler homodyne detection optical path of the light energy loss, interfer- ence figure problem of low contrast and low signal-to-noise ratio, this paper compares three kinds of all-fiber laser Doppler homodyne detection optical path. Analysis of four light path and calculate the optical power of each optical fiber passive components in the total loss and the overall utilization rate of light path of light, some comparative experiments of three light path design, the optical power meter and plug-in return loss instrument measured for three kinds of optical path of light power; Through observing three kinds of interference of light path photodetector output waveform, and cal- culated the interference figure contrast. The measured results show that the calculation results and experiment results, the optical path of the light energy loss is lower, the output of the doppler signal amplitude greatly, signal the higher sig- nal-to-noise ratio, the higher the contrast.