基于1.55μm的全光纤测速激光雷达

针对传统相干激光雷达难于实现本振光与信号光波前匹配的问题,设计了一种基于光纤低损窗口1.55μm的全光纤测速激光雷达.系统以全光纤器件构成整个光路结构,偏振无关光纤环形器与Cassegrain型望远镜组成收发合置光学天线.给出了激光雷达的整体方案和系统设计,并对接收机的光混频、天线与单模光纤的耦合、信号检测和数据采集处理等技术进行了讨论.通过实验说明,全光纤测速激光雷达对空间光随机噪声有较好的抗干扰能力,提高了干涉条文可见度和雷达系统的性能,所得的速度分辨率优于0.5mm/s,输出非线性度小于0.1％.

All-fiber laser radar at 1.55 μm for speed measurement

Strict optical alignment is essential for conventional coherent laser radar to match the local oscillator (LO) and signal modes. The scheme and system design of simple, continuous-wave (CW) coherent laser radar at 1.55 μm for speed measurement were presented. The system was based on all fiber instruments. A polarization-independent fiber-optic circulator and a Cassegrain telescope were used as the monostatic optical antenna. The fiber mixing technique of the receiver, the coupling efficiency between antenna and single-mode fiber (SMF) for spatial light, signal detection, digital data acquisition and processing were discussed. The experimental results indicate that the laser radar system has good robustness to random fluctuation noise of spatial light. In addition, the interference fringe visibility and the performance of the laser radar system are enhanced greatly. The speed resolution is less than 0.5mm/s, and the output nonlinearity of this laser radar is less than 0.1％.