Study on dispersion characteristics of phase modulation in liquid crystal spatial light modulator
Beijing Jinkun Technology Co., Ltdwww.jonkon.com.cn
pickTo: Propose to use ellipsometer method to test self-madeLiquid crystal spatial light modulator（LCSLM）The phase modulation dispersion characteristics of the ellipsometer method. The ellipsometer method has the advantages of simple and single optical path, accurate results, and automated testing. Compared with the monochromatic light source interferometer measurement method, it is simpler and more practical. The results show that in short wavelengths（450 nm）Here,LCSI MThe phase modulation capability is1．54λ（ λ=450 nm）At long wavelengths（800 nm）place,LCSLMThe phase modulation capability is0．70λ（ λ=800 nm）The dispersion characteristics are basically consistent with theoretical analysis
Keywords: LCD;spatial light modulatorDispersion; ellipsometer
Classification number:0753；TP217Document identification code:AArticle Number:1004—4213（2007）06—1065 3
0 Introduction
Under different wavelengths and voltages, liquid crystalsspatial light modulatorIt has different phase values. This dispersion characteristic can be applied in many fields such as dispersion compensation, white light wavefront correction, optical communication, etc., and has a very broad application prospect. Currently, research on the dispersion characteristics of liquid crystals mainly focuses on liquid crystal birefringence△nThe study of light intensity did not take into account the phase dispersion characteristics after applying voltage. Most phases are measured using interferometers, so the phases are measured at a single wavelength. Interference measurement has a complex optical path and complicated testing methods, and dispersion phase measurement requires the introduction of a spectrometer to generate a monochromatic light source, which is then measured separately at different wavelengths. This article proposes the use of a spectroscopic ellipsometer measurement method, which has the advantages of simple optical path, accurate results, and automated testing. The spectroscopic ellipsometer is used to achieve liquid crystal measurementlight modulatorIn450 nmto800 nmPhase measurement within the wavelength range