Design Schemes Of Diffractive Optical Element For Beam Shaping And Axicon Focusing

Binary Optics was first introduced by Veldkamp, a member in MIT Lincoln laboratory, at the end of 1980's. The correspondent technologies have been fertile after developments during above twenty years. A great number of optimistic design methods, such as simulated annealing algorithm, genetic algorithm, etc. were improved. At the same time, advances in micro fabrication technology promoted the fabrication precision. For example, the critical dimension reaches 50nm by use of electron-beam direct writing technology. All these new optimistic design methods and the precision fabrication tools bring out the upsurge to apply the DOEs in more and more fields. In this dissertation, the design methods of DOEs for micro-pulse lidar and plasma diagnostic are investigated.To decrease the adverse effects of the Schmidt-Cassegrain telescope used in micro-pulse lidar systems, such as low-usage of laser energy, great interference noises into returned signals and high damage thresholds required for optical elements, we designed a DOE with the effective aperture 24mm X 24mm to transform a Gaussian beam to ring-shaped profile. Moreover, we originally introduced marginal phase correction method to correct the phase of the designed DOE for better shaped-beam quality.In order to focus the probe laser beam into a long focal depth to implement the plasma diagnostics of the close target after ignition in the Inertial Confinement Fusion (ICF) experiments, the focusing characteristic and design methods of diffractive axicon are investigated.