Study On Assembly And Properties Of High Resolution LCoS Spatial Light Modulator Based On Photoalignment Technology

LCoS spatial light modulators(LCoS SLM),especially phase-only LCoS SLM which can flexibly and conveniently control the optical wavefront,have extremely important applications in telecommunications,digital holography,microscopy and other fields and are core components of wavelength selective switch(WSS),maskless lithography system and holographic optical tweezers system.It is valuable to optimize assembly techniques for LCoS devices and to study the electro-optic characteristics of high resolution LCoS spatial light modulators.In this thesis,high-resolution phase-only LCoS spatial light modulators are studied.This thesis mainly consists of the following three aspects.1.Assembly and characterization of phase-only LCoS SLM devices.The advantages and disadvantages of several working modes for phase-only modulation are analyzed and compared,and the ECB mode is chosen for the phase-only modulation.The photo-alignment technology is applied to the assembly of LCoS devices,and the assembly techniques of LCoS devices under laboratory conditions is optimized.The samples of phase-only LCOS devices,working at 532 nm in the visible light range and 1550 nm in the near IR range respectively,have been successfully assembled.A test system is built to measure the phase modulation range and response time of the device samples.The results of measurement show that the phase modulation range of the samples meet the application requirements.2.The simulation research of restraining fringing field effect on high-resolution LCoS devices by orientation arrangement of pixel level precision of liquid crystal molecules.A working mode of ECB mode with opposite pre-tilt angles for adjacent pixels is designed.And the influence of fringing field effect on LCoS devices in this working mode is analyzed.The results show that the working mode restrains the fringing field effects on the adjacent pixels on both sides of the target pixel,while the fringing field effects on the pixel edges of the other pixels is enhanced.The working mode needs to be further optimized in combination with other factors.3.Study on assembly techniques of out-of-screen alignment for LCoS devices based on photo-alignment technology.The samples of liquid crystal cell are assembled by this process and the pre-tilt angle of the samples is measured.Then,the influence of the process on the pretilt angle is analyzed,which lays a foundation for the application of the new process of out-ofscreen alignment.