Study on Sensing Head for Selfmixing Laser Doppler Velocimeter

提出了一种基于Y分支波导和光纤透镜的双光束自混合激光多普勒测速仪的新型结构。然后，在Y分支光波导边放置一个光纤透镜，完成了实验。对单模光纤(SMF)和塑料光纤(POF)作为光纤透镜进行了比较，证实了紧凑型LDV传感头的可行性，并发现了一种采用V型光纤的双光束照射头的新结构。成功地实现了双光束辐照，并且可以用单根光纤测量物体的速度。

We have proposed a new structure of two-beam irradiation head using Y-branching waveguides and a fiber lens for Selfmixing laser Doppler Velocimeter.First, velocity measurement was studied with Y-branching waveguides only. Then, setting a fiber lens on the edge of Y-branching waveguides, we accomplished the experiment. Comparison between a single-mode fiber (SMF) and a plastic optical fiber (POF) as a fiber lens was made.It was confirmed that the sensor head of compact LDV was possible.In addition, we found that a new structure of two-beam irradiation head using a V-shape fiber. Two-beam irradiation was successfully achieved and the object velocity could be measured using a single fiber.