扩展光源准直照明系统出射光束发散特性的研究

Divergence Characteristics of Outgoing Beam from a Collimating Illumination System with an Extended Source

扩展光源准直照明系统的出射光束发散特性决定了其极限照明距离的大小。基于费马原理,给出了平凸准直透镜面型的解析表达式,根据成像光学相关理论推导出扩展光源条件下准直照明系统中出射光束发散角的计算公式,并进行了模拟仿真和实验验证。研究发现扩展光源准直照明系统中出射光束的发散角与光源发光区域的尺寸成正比,与准直透镜的焦距成反比,与透镜口径无关。该结论可为扩展光源准直照明系统出射光束发散角的压缩和极限照明距离的拓展提供理论依据,对探照类灯具研制中光源的选择、准直配光透镜的设计有指导意义。

The limiting distance for illumination from a collimating illumination system with an extended source is determined by the divergence of the outgoing beam.Herein,the analytical expression for the surface of the plano-convex collimating lens based on Fermat's principle was obtained.The formula for calculating the divergence angle of the outgoing beam in such a system was derived according to the theory of imaging optics.Simulations and experimental validation were also conducted.Results reveal that the divergence angle of the outgoing beam from the collimating illumination system with an extended source is proportional to the source size,inversely proportional to the focal length of the collimating lens,and independent of the lens aperture.This conclusion provides a theoretical basis for compressing the divergence angle of the outgoing beam and extending the limiting distance for illumination from a collimating illumination system with an extended source.It has guiding significance for the selection of the light source and the design of the collimating lens in the development of searchlights.