Study On The Technique Of Beam Shaping For High-Power Diode Lasers

Several major methods of beam shaping of high power diode lasers are reviewed in this paper. The characteristics of irradiance distribution, propagation and beam shaping of laser diode stacks are studied, which are important for designing beam shaping system in the practical applications of diode pumping solid-state laser (DPL), and medical application. A new beam shaping device of diode laser stack is presented in this paper.Numerical simulation is made to the pyramid-spherical beam shaping element. Analysis shows that this shaping element has good performance. However, the output end of the shaping element is a sphere, in practice it is difficult to polish a spherical curve in a pyramid end. We replace a spherical output end by a plane perpendicular to the optical axis. Analysis and numerical results show that this new shaping device can be used to transform the output light of a LD-stack into a plat-top beam distribution. The output intensity distribution of the two-dimensional light intensity is given for a stack diode laser consisted of 9 stripes of diode laser bars. Analysis shows that an uniform light of 7mm X 7mm can be obtained by using this system. The advantage of the new shaping element is that the structure and fabrication of this system is simple.The results of this paper could be useful for much practical work.