矢量非傍轴离轴高斯光束的传输

Propagation of vectorial off-axis Gaussian beams beyond the paraxial approximation

基于矢量瑞利-索末菲衍射积分公式,得出了波动方程的一个解,它代表矢量非傍轴离轴高斯光束,其在自由空间的传输方程表示为解析的结果.矢量非傍轴离轴高斯光束的轴上和远场公式,矢量非傍轴高斯光束的传输方程,以及傍轴的结果都可作为一般表达式的特例而得出.研究表明,f参数对光束的非傍轴特性有重要影响,而离心参数也影响非傍轴行为.与共轴情况不同的是,对离轴情况,在y方向存在场的纵向分量.

Based on the vectorial Rayleigh-Sommerfeld diffraction formulation, a solution of the electric-magnetic wave equation is found, which represents vectorial nonparaxial off-axis Gaussian-beams whose propagation equation in free space is expressed in a closed form. The on-axis and far-field expressions of vectorial nonparaxial off-axis Gaussian beams, the propagation equation of vectorial nonparaxial Gaussian beams and the paraxial results are treated as special cases of our general expression. It is shown that the f parameter plays an impotant role in determining the beam nonparaxiality, whereas the off-axis parameters additionally affect the nonparaxial behavior of vectorial nonparaxial off-axis Gaussian beams. Moreover, unlike the on-axis case, there exists the longitudinal component of the field in the y direction for the off-axis case.