为从物理层面理解亚波长金属光栅偏振透射现象以及光栅参数对偏振透射的影响，基于等效介质理论定性解释了单层亚波长金属光栅的偏振透射现象，给出了各个光栅参数对偏振性能的影响规律。对于不同条件下透射峰值产生的机理，基于法布里-珀罗共振理论给出了定量解释。对于等效介质理论和法布里-珀罗共振理论的准确性给出了验证及分析。通过两理论定性或定量的对单层亚波长金属光栅偏振器透射机理的系统分析，将有助于更清晰地理解金属光栅偏振器的偏振透射影响规律。

In order to understand the transmission phenomena of sub-wavelength metal gratings and the effect of grating parameters on polarization transmission, the polarization transmission is analyzed qualitatively based on the equivalent medium theory. The influence of the grating parameters on polarization transmission and the reason why these influences generated are presented. The mechanism of the transmission peaks is analyzed quantitatively by using the Fabry-Pérot resonance theory. The accuracy of the two theories is carefully verified and analyzed. The qualitative and quantitative analysis of the transmission mechanism of sub-wavelength metal gratings will be helpful for better understanding of the effect of grating parameters on polarization transmission.