平顶高斯光束在梯度折射率介质中的传输特性

Propagation properties of flattened Gaussian beams in gradient-index media

利用广义惠更斯-菲涅耳衍射积分法,推导出平顶高斯光束在梯度折射率介质中传输时的解析表达式,对平顶高斯光束在梯度折射率介质中的传输特性进行了分析,讨论了介质梯度折射率系数和光束阶数对传输特性的影响。研究表明,平顶高斯光束在梯度折射率介质中传输时轴上光强分布呈现周期性变化,其周期决定于介质梯度折射率系数,而与光束的阶数无关;轴上峰值处的横向光强分布受梯度折射率系数和光束阶数的影响较大,横向光强的最大值随着梯度折射率系数的增大而增大。

By using the method of generalized Huygens-Fresnel diffraction integral,the transmission analytical expression of flattened Gaussian beams in gradient-index media is deduced.The influence on the propagation properties of the medium gradient refractive index coefficient and the beam order is discussed.The results show that when flattened Gaussian beams propagate in gradient-index media,the intensity distribution on the axis varies periodically.Its change period is decided by the gradient-index coefficient,and has nothing to do with the beam order.The transverse intensity distribution of the peak on the axis is affected largely by the gradient-index coefficient and the beam order.The maximum on the plane with transversal intensity increases with the increase of the gradient-index coefficient.