余弦高斯光束通过左手平板材料的传输特性

Propagation properties of cosine-Gaussian beam through a left-handed material slab

在傍轴近似下,利用广义惠更斯-菲涅尔衍射积分公式得到了余弦高斯光束通过左手平板材料的传输公式,研究了左手平板材料的负折射率与余弦高斯光束的调制参数对光束传输特性的影响。结果表明:余弦高斯光束无论在左手平板材料内部传输还是在像空间传输,轴上的最大光强位置是光束聚焦的位置,左手平板材料的负折射率会改变光束聚焦的位置;在介质内部,平板材料的负折射率会改变轴上光强分布的形状,但不会改变像空间轴上的光强分布形状;无论是在平板材料内部还是像空间,余弦高斯光束的调制参数对轴上与横向光强都会产生影响。

Under paraxial approximation, using generalized Huygens-Fresnel diffraction integral, the propagation expressions of cosine-Gaussian beam through the left-handed material slab are got, and the influence of propagation properties of cosine-Gaussian beam due to the negative refractive index of left-handed material slab and the modulation parameter of cosine-Gaussian beam is studied. The results of the study show that：whether in the left-handed materials slab or image space, the location of the axial maximum light intensity is the position where cosine-Gaussian beam is focused, and the negative refractive index Of the left-handed material slab will change the position of the cosine-Gaussian beam focusing. The negative refractive index will change the shape of the axial light intensity distribution in the internal of the lefthanded material slab, but it won＇t change the shape of the axial light intensity distribution in image space. Whether in the internal of slab or image space, the modulation parameters of cosine-Gaussian beam can influence the axial and transverse light intensities.