光束品质因子M2对非同轴激光雷达探测性能的影响

光束品质因子M2直接影响高斯光束传播特性,光纤口径主要约束激光雷达接收系统的视场角.几何重叠因子是影响激光雷达探测性能的重要参量,其主要受激光束的发射特性、接收系统的结构等影响.通过探讨光束品质因子M2及耦合光纤口径对几何重叠因子的影响,为设计激光雷达发射接收系统,改善激光雷达的探测性能提供了优化方案.数值计算及初步实验表明,光纤的耦合效率与光纤的放置位置及光纤口径有很大的关系;几何重叠因子小于1的探测距离受到M2因子的较大影响且随着M2因子的增大而增大.

Effect of M2 Factor of Laser Beam for a Non-Coaxial Lidar System

The propagation properties of Gaussian beam are directly influenced by beam quality factor M2 and the field of view of the receiver of lidar is limited mainly by the fiber core. The geometrical form factor which influences the measurement performance of the lidar system is related strictly with the transmission properties of laser beam and the configuration of the receiving system combined with the coupling fiber and the receiving telescope. This paper discusses mainly the properties of the geometrical form factor due to the beam quality factor M2 and the coupling fiber core, in order to optimize the design of the transmitter and receiver of the lidar and to improve the detection capability of the lidar. The numerical calculation shows that the coupling efficiency of the fiber is largely related with location position of fiber from the focus of the telescope and its core; and the range in which the geometrical form factor is less than one is largely influenced by M2 factor and is increased with the enhance of the value of the M2. The preliminary experiment is used to support the analysis of the influence factors on the performance for a non-coaxial lidar system.