The Design Of Binary Optical Elements For Laser Beam Shaping

With the development of the laser, laser technology has been widely used in many fields such as industry, agriculture, medical applications, national defense and scientific research. However, the energy profile of laser beam is a Gaussian function profile and the propagation path is hyperbola, not straight line. That limits its application in many fields. So the laser beam shaping is becoming very urgent and important. Using binary optical elements for beam shaping, as one of the several typical techniques, is an effect mean.According to several algorithms defects in current designing binary optical elements for laser beam shaping, we use a new algorithm to design binary optical elements for beam shaping. In order to design processable binary optical elements, we designed binary optical elements for homogenization of laser beam based on ZEMAX, which is able to transform the Gaussian laser beam into flat-top ones. Our research mainly includes the following works:(1) Several methods to achieve laser beam shaping are introduced. And the principle of beam shaping, origin and development about binary optics elements are instructed, too. Many methods using to design the phase of binary optical elements are discussed.(2) We have used new algorithms to design binary optical elements. Artificial Fish-swarm algorithm is put forward for designing binary optical elements for laser beam shaping, aiming at increasing the speed of optimization for BOE and improving its diffraction efficiency. The method is used to design a binary optical system with 16 grey levels to implement the wavefront transformation from Gaussian beam to circularly flat-top beam. Computer-designed result by using Artificial Fish-swarm Algorithm leads to an excellent output beam.(3) Homogenization design in Gaussian laser beam transformation based on ZEMAX. Based on ZEMAX, the Macro instructions are written to optimize the binary optical elements for laser beam shaping.