Study On Beam Properties Of High-power Laser Diodes

Semiconductor lasers have become irreplaceable components of many modern optoelectronic and photonic systems. But because of its construction of waveguide, the output beam of a LD must be shaped in most application. Therefore , study on the far-field distribution of the LD beams is desirable to design optic system properly.In this paper, the major task is summarized as follows:The basic construction and principle of diode lasers are introduced here. At the same time, the merits and demerits of LDs available are pointed out. Then the models describing far-field distribution are presented.Based on the Helmholtz equation, two decentered Gauss beams are used to represent the distribution of the source at the direction parallel to the junction plane, then a new model describing the double-peak beam of high-power laser diodes is presented.By use of the computer fitting technology , the theoretical model is compared with the measured data of three high-power laser diodes available . It is shown that the model agrees well with the measured data, and the overall error of the intensity is less than 6%-7%.Furthermore, the theoretical model presented here is applied in describing the far-field distribution of diode laser bar. Theoretical curve is given in this paper.Because of its simple structure, the model presented in this paper can be used to design shaping system or analyze the propagation properties when the laser beam passes through a optic system, and is helpful for calculating coupling efficiency.