激光测距中共光路激光发射关键技术研究

Based on the 1.2 meter telescope co-optical path laser ranging system of Yunnan observatories, the project is to study on key technologies of laser transmitting, which include technical methods in precise examination of wave aberration in laser transmitting, optic path misaligned correction, and beam quality deterioration reduction; technical methods in laser divergence examination and precise configuration; technical methods in precise examination of laser transmitting direction in co-optical path laser ranging system, and maintenance of high level of parallelism between the laser transmitting direction and the optical axis of the telescope. The problems of laser transmitting in co-optical path laser ranging are expected to be solved through the research on the project. The result can be directly applied to co-optical path laser ranging system, help to make full use of the advantages such as larger aperture and better coaxality in co-optical path laser ranging system, be beneficial to target aiming and echo enhancement, and be of great significance of lunar laser ranging and diffuse reflection laser ranging. Beam quality improvement and laser divergence angle precise configuration in separated path laser ranging system can also be achieved as using the result of the project for reference.

本项目基于云南天文台1.2米望远镜共光路激光测距系统，研究激光发射的关键技术，包括：精密检测激光测距的光束波面误差并修正光路失调，从而减小光束质量劣化的技术方法；检测激光发散角、精确设定激光发散角的技术方法；精密检测共光路激光测距系统激光发射方向、保持激光发射方向与望远镜视轴高度平行的技术方法。通过本项目的研究有望解决共光路激光测距中激光发射的问题，研究成果能够直接应用于共光路激光测距系统，充分发挥共光路激光测距系统望远镜口径大、发射光路与接收光路同轴性好的特点，利于瞄准目标并增强回波，对于月球激光测距、空间碎片激光测距具有重要意义。分光路激光测距系统也可以借鉴本研究项目的成果来提高激光发射时的光束质量并精密设定激光发散角。

激光束的发散角，激光发射光轴、回波接收光轴与望远镜的同轴度是共光路激光测距最关键技术指标之一，因回波光子数与激光发散角的平方成反比，减小激光发散角可有效提高激光测距回波光子数；保持激光发射光轴与望远镜同轴可增加共光路激光测距成功成功率，利于瞄准目标并增强回波。本项目基于云南天文台1.2米望远镜共光路激光测距系统，研究激光发射的关键技术，采用标准光源和剪切干涉仪精密检测激光测距的光束波面误差并修正光路失调，减小光束质量劣化；采用剪切干涉仪检测激光发散角、精确设定激光发散角，使得激光发散角控制到1″以内；采用二次成像方法精密检测共光路激光测距系统激光发射方向，保持激光发射方向与望远镜视轴高度平行，同轴度达到1″。通过本项目的实施，解决了共光路激光测距中激光发射的问题，研究成果已经用于1.2米望远镜月球激光测距中，是云南天文台月球激光测距成功的关键技术之一。