消色差相位延迟器可以在较宽光谱范围内获得所需要的相位延迟量,是偏振光调制的核心元件之一。根据严格耦合波理论和遗传算法,提出了一种基于夹层式亚波长金属介质膜光栅的宽光谱消色差相位延迟器的设计方法,并设计了一种在900~1200nm波长范围内实现消色差的相位延迟器,其相位延迟量在90°左右的最大偏差小于2.3%,且横电波和横磁波的衍射效率均高于90%。数值分析表明,所设计的消色差相位延迟器对槽深和入射角具有较大的工艺容差。该消色差相位延迟器设计简单,性能稳定,具有重要的应用价值。 Achromatic phase retarders achieve the required amount of phase delay over a wide spectral range and are one of the core components of polarization modulation. According to the strict coupled wave theory and genetic algorithm, a method of designing a wide-spectrum achromatic phase retarder based on the sandwich sub-wavelength metal dielectric film grating is proposed and an achromatic phase retarder is designed to achieve achromaticity in the wavelength range from 900 to 1200 nm The phase retarder has a maximum deviation of less than 2.3% at a phase delay of about 90 ° and a diffraction efficiency of both transverse and transverse magnetic waves higher than 90%. Numerical analysis shows that the designed achromatic phase retarder has larger process tolerance to the slot depth and incident angle. The achromatic phase retarder has the advantages of simple design, stable performance and important application value.