Preparation and characterization of quarter-wave plate at 12.4 μm based on CdSe single crystal

Abstract

CdSe single crystal with good optic properties is great candidates for optical devices. In this paper, CdSe single crystal was grown by the modified vertical unseeded vapor sublimation method with the diameter of 36 mm and the length of 40 mm. The quarter wave plates of CdSe single crystal with size of 20 mm×20 mm×3 mm was cut along the (001) orientation. The transmittance of the CdSe wave plate was about 69% in the range of 8-14 μm, where the absorption coefficient was about 0.04 cm-1. The phase delay was 90.71176 ° at 12.4 μm, which less than 5%. This work disclosures a high-quality and large size wave plate of CdSe single crystal, such wave plate has wide application prospects in mid-infrared.