Study On Properties Of Phase-Only Liquid Crystal Spatial Light Modulator And Application On Diffractive Micro-Elements

Micro-optics which is one of three major components of the micro optical electro-mechanical systems, represents one direction of information optical development. Micro-optical elements have extensive applications in optical fiber sensing, optical information processing, image-forming system, optical communication, optical computation, optical interconnection and optical storage etc. Moreover, variable micro-optical elements have wide use in imaging, wavefront adjustment and optical interconnection and so on. The electric-control liquid crystal spatial light modulator (LCSLM) recently has been attracting intensive research efforts due to their high diffraction efficiency, convenient controlling and fast responses, etc. The phase-only LCSLM has high the diffraction efficiency since they eliminate amplitude modulation. Using the phase-only LCSLM as diffractive micro-optical elements has good applications.We review the development and availability of LCSLM and micro-optical elements briefly, and explain the chief performance parameters of the phase-only LCSLM which use in the experiment. By introducing current-illumination characteristic of liquid crystal, we analyze the phase-modulated principles and properties of liquid crystal. Comparing with some measuring methods of phase-modulated characteristics of LCSLM, we select the Twyman-Green Interferometer to measure them in experiment. With analysis and comparison, we optimize the phase-modulated characteristics of LCSLM, modify the Look-up Table, and advance the measurement accuracy. Now the related coefficient of ideal modulation curve increase from 0.982806 to 0.995267.Without conjugate image or redundant diffraction series, kinoform is an ideal element of wavefront Reconstruction, which only generates single imaging optical waves and has high diffraction efficiency. We analyze the calculation and reproduce principle of kinoform and study various parameters on the impact of quality of Kinoform reconstruction image. Inputting the calculated kinoform to the LCSLM, it can be realized much different function by using phase-modulated characteristics of LCSLM that transforming parallel light into specific wave-front beam. Through theoretical analysis and experimental verification, we implement some devices such as zoom lens, zoom lens array, optical scanning and arbitrary wavefront reconstruction etc. Although it is restricted by the performance of LCSLM, the performance of the diffraction component is satisfying.