面向宽谱段共焦测量的消像差准直会聚方法

Aberration-free collimation convergence method for broadband confocal measurement

针对宽谱段定焦系统存在色散严重、像差较大的问题,提出一种面向宽谱段共焦测量的消像差准直会聚新方法。该方法利用全反射式结构抑制不同波长定焦时造成的色散效应,利用抛物面结构和环形光束抑制像差,在可见至红外宽谱段内实现了对光束的精确准直与会聚,相对于现有准直会聚方法可以消除色散且明显抑制像差。理论分析和初步实验表明：依据该方法构建的准直会聚系统在不同波长光源情况下聚焦点完全重合,定焦曲线旁瓣得到明显抑制,且定焦分辨力达到72.4μm@1 064 nm,接近环形光束聚焦情况下的理论计算极限。

To solve the problem of large dispersion and large aberration in the broadband focusing system, a new method of collimation and convergence for aberration-free confocal measurement is proposed. The method uses a total reflection configuration to suppress the dispersion effects caused by different wavelength focusing, and utilizes a paraboloid configuration and annular beam to suppress aberrations. In this way, the accurate collimation and convergence of beams in the visible to infrared range can be realized. The collimation convergence method can eliminate dispersion and significantly suppress aberrations. Theoretical analysis and preliminary experiments indicate that the focal points completely coincide when the different wavelength light sources pass the collimated convergence system constructed by using this proposed method. The sidelobes of the focusing curve is significantly suppressed. The focusing resolution reaches 72.4 μm@1 064 nm which is close to the limit of theoretical calculation in the case of annular beam focusing.