分析了视场展宽迈克耳孙干涉仪(FWMI)用作高光谱分辨率激光雷达(HSRL)光谱滤光器时一个未引起广泛重视却又非常重要的问题：FWMI增透(AR)膜反射率容差评估。由于FWMI不同材料分界面的AR 膜无法做到100%透射，一旦光线经过该表面，将引起部分光被反射，且这部分光线将成为游离光线在干涉仪主体中不断被多次反射。分析了AR膜反射率导致的多次反射对FWMI滤光性能的影响机理，并采用光谱分离比(SDR)作为性能量化指标，提出了一种迭代算法来定量评估FWMI光谱分离特性与AR膜反射率的关系。分析结果表明，AR膜反射尽管对大气分子散射信号的透射率影响不大，但会较大的降低FWMI对气溶胶散射信号的抑制能力，最终总体上导致SDR 的降低。本方法对FWMI AR 膜反射率容差评估具有较大的参考价值，是保证FWMI良好设计性能的重要方面之一。

A significant yet not widely realized topic is analyzed when the field-widened Michelson interferometer (FWMI) is used as a spectroscopic filter in high spectral resolution lidar (HSRL), that is, tolerance evaluation for anti-reflection (AR) coating reflectivity of the FWMI. Since AR coatings on the interface of different materials in the FWMI cannot be with 100% transmittance, a part of the radiation would be reflected back once the light passes through these surfaces, and these reflected lights would be further reflected many times in the interferometer as stray lights. The influence mechanism on the FWMI performance due to the multi-reflection caused by AR coating reflectivity is analyzed, and an iterative algorithm is proposed to estimate the relationship between the performance of the FWMI and the reflectivity of the AR coating quantitatively, using the spectral discrimination ratio (SDR) as the performance metric. Results show that the reflection induced by AR coating will degrade the suppression ability of the FWMI to the aerosol scattering while it imposes no effect on the molecular transmittance. The overall consequence is to make the SDR of the FWMI decrease. This method can provide considerable reference for the tolerance evaluation of AR coating reflectivity in FWMI, and is one of the important aspects that can guarantee good design performance of the FWMI.