基于非球面透镜的空间光场光纤耦合系统研究

针对全光纤激光雷达中空间光场与单模光纤的耦合问题,设计了基于非球面透镜的望远镜光纤耦合系统.利用ZEMAX软件以单模光纤耦合效率为优化目标对其结构参量进行优化设计,然后分别用LED和激光器作为光源进行初步实验,比较直接耦合和非球面透镜耦合效果.实验结果表明,采用非球面透镜耦合可使多模光源的耦合效率比直接耦合增加约47％,与仿真结果45％非常接近,且不同芯径耦合光功率之比大略等于芯径比平方;而该耦合方式可使单模光源的耦合效率增加约20％,且耦合进不同小芯径光纤的耦合效率之比约为其芯径比平方的2.4倍,这对构建全光纤转动喇曼激光雷达系统具有重要意义.

Fiber Coupling System of Space Optical Field Based on Aspheric Lens

A telescope fiber coupling system using aspheric lens for coupling free space optical field into single mode fiber in all fiber lidar is devised. Its layout is designed and optimized for coupling efficiency into single mode fiber through ZEMAX software. Moreover, the preliminary experiments are carried out using the LED and laser as optical source, and then the coupling efficiencies of directive coupling and aspheric lens coupling are compared. Experimental results show that the coupling efficiency using aspheric lens for multi mode optical source may be increased by 47% than that of directive coupling, which is close to simulating result of 45%, and that the ratio of coupling optical power for different fibers is roughly close to the square of the core diameter ratio. Furthermore, it is shown that the coupling efficiency of this way for single mode optical source may be raised by 20%, and that the ratio of coupling optical power is approximately 2.4 times more than the square of its core diameter ratio, which is significant to establish the all fiber rotational Raman lidar.