The Study Of Rapidly Response And Electronically Controlled Liquid Crystal Phase Grating

In the last decades, the Optical communication technology is widespread concern in the scientific community and the beam deflection control technology is an important part of optical communication technology. The traditional technology rely on mechanical deflection such as array lens. These devices are not only big volume and complex structure but also high cost and power consumption. With the booming of photoelectricity technology, the development of optical device is turning towards low power consumption, lightweight and high precision. Among many optical devices, the liquid crystal devices overcome the disadvantages of the traditional projection techniques. Liquid crystal devices are widely used in display and optical modulator fields. The liquid crystal phase grating exhibits the attractive property of the tunable diffraction, low driving voltage, no moving parts, low power consumption, small volume, highly reliability, and so on. Thus, the liquid crystal phase grating is applied to projection display, space communications,3D display, beam deflection field, the target scanning and optical information processing systems.A rapid response liquid crystal phase grating was present in this thesis, in view of the response speed of nematic liquid crystal phase grating is slow. We presented a oriented pattern. The diffraction efficiency and the response time were studied and compared with the same parameters parallel oriented liquid crystal phase grating. The result showed that the bend oriented liquid crystal phase grating behaves a higher diffraction efficiency than the comparative parallel oriented ones and shorter in response time. Specific researching works were done as following:1. Polyimide (KPI-2088) and thinner (NMP) in accordance with different mixing ratio to control pre-angle. The response time of liquid crystal phase grating was measured under different pre-angle and we get the fastest response time of 2.98ms. As the same time, we compared the diffraction efficiency of bend and parallel oriented phase grating. It was found that the diffraction efficiency of bend oriented is higher than parallel oriented.2. In order to further speed up the response time of liquid crystal device, the experiment used overdrive method to improve the response time and found the best interval time. The fastest response speed was increased from 2.98ms to 2.25ms.3. Using mixed horizontal polyimide (KPI-300B) and vertical polyimide (SE-4811) to achieve stable pre-angle of 7 degrees. We compared the response time and diffraction efficiency of bend and parallel liquid crystal phase grating. It was found that the fastest response time is 5.6ms bend oriented and has high diffraction efficiency...