微米级光学光斑测量系统设计

Design on micron-level optical light spot measurement system

微米级测量光斑是激光非接触共焦法测量核聚变微靶的一项重要指标。要使测量精度达到1μm,测量光斑直径也应在微米级。根据激光高斯分布理论,设计加工了在GJ—Ⅳ共焦测头上实现微米级焦点光斑的光学系统进行了测量误差分析。通过实验和测试,激光测量光斑为10μm,工作距离为20 mm,测量精度为0.04%。实验数据证明:设计的光学系统从测量范围、测量光斑尺寸、测量精度等方面均满足微靶球测量的要求。

Micron-level measurement light spot is an important quota for confocal laser with non-contact surveying micro-target in fusion. The spot size was needed to be micron level to realize precision 1 μm theoretical analysis. According to the Guass distribution of laser theory, the optical system of GJ-IV confocal probe was studied, not only from the stucture, but also the parameter in order to achieve micron-size focusing spot. En＇or analysis of the measurement was followed. The experiment showed that when the measuring spot size was 10 μm,working distance was 20 ram,measuring precision is 0.04 %. It was fully demonstrated that the designed optical system satisfied the need of the micro-target measurement. In many aspects, such as measuring scale, measuring light spot size, measuring precision, etc. It can promote the progress of laser-based nuclear fusion, which had great practical value.