Beam Shaping For Semiconductor Laser Array

In recent years, the semiconductor lasers has been widely applied in many application fields such as pump solid laser, material processing and laser medical exposure for that they have characters such as little volume, light weight, the intensive energy of the beam, longer life, higher reliability,higher repetition rate, higher efficiency and the compact structure.However, the semiconductor lasers have a high divergence angle and the obvious difference is survived between the horizontal direction and the perpendicular direction, so the bad performance of its output beam, which affects its direct application, make it a hot view which people pay much attention on how to transform the beam of the high efficient laser diode array.Internal and abroad institutions have been doing much research on the problem.On the basis of summarizing various methods for beam shaping from those reports, we have designed a set of aspherical lens system for the laser diode array.First,according to the method of light-ray tracing,we inferred the principle of collimation with orthogonal cylinder-hyperboloid cylinder lens and the principle of compression with ellipse-plane cylinder lens and plane-cylinder lens. Finally we obtained the actual parameters of the shaped-apparatus for the semiconductor lasers with special divergence, which provides reference in theory to design the parameters of the shaped-apparatus of the semiconductor lasers.Based on the theoretical inference,the shaped-apparatus were made by ourselves and the experiments showed the system had good effect.The thesis includes four parts. The first chapter introduces the development of the semiconductor lasers,the necessity and actualities of beam-shaping.The structure and characteristics of the semiconductor lasers and the basic theory are introduced in the second chapter. The third part of the thesis discusses the collimation principle and the compression principle and design the beam-shaping system.The experimental results have been described in the forth chapter ; the results verified the feasibility of the system and the error analysis is made. Lastly,the conclusion is made in the fifth part.