Research On LD Beam Collimation System With Variable Divergence

This paper provides an overview of status about laser beam shaping at home and abroad. The theory of beam shaping transformation, including geometric optics and matrix optics, is presented. Characteristics of high-power laser diode beam is analyzed, the output characteristic of laser diode beam is described in Hennite-Gaussian laser beam.In this article we describe a method for collimating LD beam, which can make the divergence angle of beam variable in a certain range. Hence, the LD beam collimation system with variable divergence is designed. The collimation system consists of a cylindrical lens and a GRIN lens. The effect of a cylindrical lens is to compress the divergence angle in fast axis direction and regulates the astigmatism. The GRIN lens is the role of converging the angle and making the divergence variable. We simulate the collimation system for a LD whose wavelength is 0.808um in commercial lens design software, and results show that the angle can change continuously in under conditions of collimation. The system has the small volume, and is easy to integrate.