Research on the Deflection Characteristics of Non-Mechanical Beams of Liquid Crystal Variable Retarder Cascade Polarization Gratings

Abstract

According to the research status of fast beam pointing and scanning in space laser communication, this paper proposes a beam deflection method that cascades liquid crystal tunable phase retarder with polarization grating, and realizes fast beam scanning and pointing according to the polarization and diffraction characteristics of light and analyzes the relationship between voltage and delay, the voltage regulation accuracy is 0.001 V, and whether the spot intensity can be used in space laser communication is verified, and the fast pointing of four spots of ±6° and ±2° is realized. The pointing accuracy is 30.49 μrad, the beam divergence angle is about 0.0339°, and it is connected to the blazed grating, and the single beam is scanned at 4.062° and 16.06° by wavelength tuning from 1525 nm to 1600 nm, with a wavelength tuning accuracy of 0.01 nm and repeated positioning accuracy of about 0.01°, which has certain research significance for the miniaturization and lightweight design of space laser communication optical transceiver and lidar.

Keywords

• Diffraction characteristics
• liquid crystal variable retarder
• non-mechanical beam deflection
• polarization grating