| This dissertation is related to the fundamental physics of liquid crystal (LC) diffractive optical element (DOE) and its application in beam steering, wavefront control in large optics, electronic holography etc. Extensive computer modeling is performed to study the fundamental physics of LC DOE that involves advanced simulation method such as: Finite Difference Time Domain (FDTD) simulation, CODE V ray tracing and diffractive beam propagation, 2-D and 3-D liquid crystal director simulation etc. As a result, fringing electric field effect, defect formation, diffraction efficiency, polarization effect in a high resolution OPA is quantitatively studied. Many new device structure and concepts that can substantially improve the efficiency and diffraction angle of a LC DOE is proposed, for example, an optimized OPA, a pinned electrode OPA, a non-symmetrical variable period binary grating etc. FDTD simulation with both TE and TM mode is carried out, light propagation in LC DOE with complicated 3-D director distribution is studied. Experimental study is carried out to verify the modeling results constantly. 2-D birefringence measurement, Electro-Optical response of the device, as well as the diffraction efficiency, near field phase distribution, wavefront quality, far field beam profile is carried out to study the optical performance of the LC DOE. High resolution wavefront control system for large aperture telescope based on a LC DOE is demonstrated. |
