Far-field Intensity Distributions of High Power Semiconductor Lasers

Based on the decentered Gaussian model,using the vector Rayleigh-Sommerfeld far-field diffraction integral formula,a vector model to describe the propagation of a high-power laser diode,and the far-field characteristics of a bar laser diode are presented.Through the analysis of the properties of the TM-mode propagation,the expressions of optical intensity and divergence angle are deduced,and the error is also analyzed compared with the scalar theory.It is found that the far-field intensity distribution and the divergence angle are all different between the vector and scalar model.The error of intensity distribution is proportion to the coordinate perpendicular to the junction plane and inverse to the propagation distance.As the distance of the observation point from the bar laser diode increases,the beam spots of the emitters begin to overlap,and even to form a flattop distribution in a large distance region.If the distance of the observation point is large enough,the intensity distribution of the bar laser diode is equal to the distribution of a single emitter.