Study On Driving Circuit And Optical Properties Of A LC-SLM

Liquid Crystal Spatial Light Modulator (LC-SLM) is the key element in the optical information processing, which is especially suitable to be applied in the equipment of the optical pattern recognition. Generally speaking, each type of LCD has a specific driving circuit with fixed parameter. The thesis focused on the universal driving circuit and the optical applications of LC-SLM.Firstly, the thesis developed a universal driving circuit for LCX016, which used a CPLD as the core control chip. Under the control of the write/read signal and video frame and line synchronization signal generated by the CPLD, image data were written into two high speed IS61LV5128AL via serial interface and a MCU. In each refreshing cycle the image data were transformed by D/A converters, then written into each pixel of LC-SLM. The CPLD logic was realized using Verilog HDL under Quartus II environment.Secondly, the thesis analysed theoreticaly the optical properties of a LC-SLM. Optical experiments were carried out on above hardware and software platform. It was observed that when the polarizers changed their directions, the image changed from a clear to a fuzzy state, then to a reversal state and become clear again when the polarizers restore their original direction. The results coincided with theoretical calculation.Finally, the thesis constructed a 3*4 Frensel Zone Plates arry on above LC-SLM. The 3*4 dot matrix was obvserved on the focus plane as expected. These experiments indicated that the driving circuit was stabile. With some software modification for CPLD, the driving circuit can also be used to drive other types of LC-SLM.