闪电场景模拟系统中需要不同强度分布的光轴平行的多路光束, 多棱镜分光系统能够实现平行光束增宽和强度分布调制。为获取彼此平行的多路光束, 采用五棱镜扫描法完成等间隔分布的四棱镜分光系统的多光束光轴平行度检测, 通过CCD采集返回的与特定光轴位置信息有关的光点光强分布, 并编制相关的软件计算质心偏差, 为分光棱镜的定位装校提供直观准确的反馈信息, 装校装置具有简单方便的特点。装校后的四棱镜分光系统在x、y、z 3个方向上的光轴匹配精度分别小于3′、4′和4.5′, 4束平行光的光强之比约为8∶4∶2∶1。进一步提高CCD分辨率和增大成像物镜L的焦距后, 光轴的匹配精度可以达到秒量级。

Multiple prism beam splitter can enlarge the parallel beam width and arrange the intensity distribution, which is used in the experimental simulation of lightening optical emission with different intensity distribution and high parallelism multi-channel beam. In order to obtain multi-channel parallel beam, penta prism scanning method was applied to test the multi-channel beams′ parallelism in four-prism beam splitter with four prisms equally separated in the mechanical foundation. After we acquired the intensity distribution diagrams related to multi-channel optical axis by CCD, the software of centroid deviation calculation was programmed to feedback the accurate site-deviation information for prism calibration, which had the advantages of simpleness and convenience. The calibrated four-prism beam splitter had the optical axis matching precision less than 3′, 4′ and 4.5′ in x-direction, y-direction and z-direction respectively, and the ratio of four-beam parallel light′s intensity was about 8∶4∶2∶1. If the resolution of CCD is improved and the focal length of the objective is enlarged, the precision of optical axis matching will achieve the seconds order.