激光雷达不仅可用于分析目标光谱特性, 还能够获取空间目标方位、距离、三维形貌及运动特征。常规激光雷达测量的目标特征单一, 难以同时具备以上所有的探测能力。针对激光雷达的多种功能需求, 设计了一种同时具备以上多种测量能力的激光雷达, 采用发射/接收共光路系统结构形式, 极大地简化了光学系统结构, 光学系统为特殊的折反射结构, 在仅使用两种光学材料的情况下即可实现400~1400 nm宽波段的发射与接收。为实现多谱段探测, 激光光源采用光参量振荡器单脉冲可调谐激光器, 光谱调节范围覆盖整个探测波段。激光发射系统的激光等效扩束比达到12.6, 单色回波接收系统等效F数为8, 采用光电倍增管, 20 μm内的径向能量接近100%。为满足对目标的跟踪与精细结构测量, 在共光路的基础上, 加入可见光接收系统, 使多谱段激光雷达还具备可见光成像能力, 可见光接收系统全视场为1.6°, 所设计的调制传递函数在37 lp·mm-1处优于0.5。系统各项设计指标满足探测需求。

Laser radar can be used not only to analyze the target spectral characteristics, but also to obtain the spatial orientation, distance, three-dimensional profile and movement characteristics of the target. The conventional lidars can only measure single characteristic of the target, thus it is difficult to obtain the above measurement features of the target at the same time. To meet the multi-functional requirements, such kind of lidar with the above measurement capabilities is designed. The structure of the optical system is greatly simplified by adopting transmitting/receiving common optical system. The optical system, with a special refraction /reflective structure, can achieve 400-1400 nm wide band transmission and reception by using two kinds of optical materials. To achieve multi-spectral detection, the laser light source uses an optical parametric oscillator single pulse tunable laser, of which spectral adjustment range covers the entire detection band. The equivalent beam expansion ratio of the laser emission system reaches 12.6, and the equivalent F number of monochrome echo receiving system is 8. The radial energy within 20 μm is close to 100% with the photomultiplier tube. In order to track and finely measure the structure of the target, a visible light receiving system is adopted to the common light path. Thus, the multi-spectral laser radar has visible light imaging capabilities. The full field of view of the visible light receiving system is 1.6°, and the designed modulation transfer function is better than 0.5 at 37 lp·mm-1. The design parameters of the system meet the detection requirements.