半导体激光器光束由于其波导结构，出射光束发散角很大，属于非傍轴光束，使得用傍轴理论处理精度不高。为了精确地描述光场分布，需用更精确的非傍轴矢量理论进行分析。针对半导体激光器光束传输特性，运用光波矢量传播理论进行分析，由半导体激光器出射面光场给定边界条件，并运用瑞利矢量衍射积分公式，可以得到光场的半空间表示式，进而用稳相法进行计算，得到半导体激光器的远场矢量表示式。分析结果表明，在非傍轴区，光场传输方向分量不能忽略，矢量理论分析更为精确。

For the beam of a laser diode, the source size is very small and the light beam has a large divergence angle. In addition, in the nonparaxial region the optical field distribution is considerably different from that given by scalar theory. The nonparaxial theory of vector beams should be used to describe these fields. A mathematical model to describe the far-field distribution of the nonparaxial laser diode beam is presented. The laser diode beam propagation is studied by the vector Rayleigh diffraction integrals, and the stationary-phase method is employed to find the asymptotic expansion of the diffraction integral. The propagation expression for nonparaxial laser diode beam is given. The calculated results show the vectorial theory model is more precise in the nonparaxial region.