Study On Nonparaxial Propagation Characteristic Of Laser Diode Beam

Owing to the advantage of compactness,lightness,high reliability,high conversion efficiency,directly modulated, semiconductor laser become the key components of information technology and play an important role in various fields such as optical communication,laser ranging,information processing and storage.Because of the waveguide properties of semiconductor laser,the output beam quality is poor with large divergence angle,the beam no longer follows the transmission of paraxial propagation.Therefore, the non-paraxial beam propagation properties must be understood more accurate in most practical work.In this paper, several basic research methods used to study non-paraxial beams are summarized,and meanwhile comparative analysis their merits and demerits.Gaussian beam is used to describe the semiconductor laser field model,based on the vectorial diffraction theory of the angular spectrum representation and take Gaussian beams through the circular aperture diffraction as an example,compared the energy transmission properties of non-paraxial scalar field and vector field.Baded on a model for describing the far field of semiconductor laser,discussing the non-paraxial beam through collimate lens.The analytical expression of collimation field is derived by the method of stationary phase,analyzed the beam intensity distribution before and after collimate lens.