远场高斯平面波折射时光斑演化特性的研究

Facula-Evolution of Far-Field Gauss Plane-Wave after Refracting

讨论了高斯光束的远场行为,给出了传播方向为任意方向、等相面为平面、幅度呈高斯分布的高斯平面波的一般表达式.分析了高斯平面波在介质分界面处的反射与折射现象:其波矢满足均匀平面波的折射反射定律,振幅最大值满足均匀平面波的菲涅尔公式.但光斑将发生演化,由圆形演化为椭圆,椭圆光斑的长短轴取决于入射介质和折射介质的折射率之比.最后给出了入射光的场强同时包含垂直入射面分量和平行入射面分量时反射波与折射波的一般表达式.

In this paper,we have discussed the Gauss beam far-field behavior, and given the generic formula of Gauss plane-wave when its propagating direction is random, equiphase surface is plane and field-intensity is Gauss distribution.Then, we've discussed Gauss plane-wave reflection and refraction at medium interface. We found that: its wave-vector tallies with the reflection and refraction law of symmetrical plane-wave; amplitude max is in perfect accord with Fresnel's formula of symmetrical plane-wave. We also found the facula-evolution phenomenon.The Gauss plane-wave's round facula evolves to ellipse. The long axis and minor axis of elliptic facula lie on the ratio of refractive index between incidence medium and refraction mediun. In the end, we show the expressions of reflection wave and refraction wave when incidence light includes two hefts:one is parallel with incidence plane,the other is vertical.