非傍轴厄米-正弦-高斯光束的特性

为了研究厄米-正弦-高斯(HSiG)光束在非傍轴情形下受参量影响的特性,基于光强二阶矩理论,经过一系列复杂的数学计算,得出了非傍轴厄米-正弦-高斯光束的远场发散角、束腰宽度以及光束传输因子的解析式,并通过数值模拟,得到了它们与离心参量的关系。结果表明,在束腰宽度与波长比取值逐渐减小时,随着离心参量趋于0,当阶数为奇数和偶数时.发散角分别趋于63.435°和73.898°。束腰宽度和光束传输因子随参量的增加呈现较大的起伏,非傍轴情形下的光束传输因子取值与傍轴情况有很大的不同,其受参量影响不仅可以小于1,甚至趋于0。

Non-Paraxial Hermite-Sine-Gaussian Beam Character

For studying the character of Hermite-sine-Gaussian (HSiG) beam in non-paraxial case, based on the theory of the second intensity moment and a series of complex calculations, the results of the far-filed divergence angle, waist width and M2 factor of non-paraxial Hermite-sine-Gaussian beams are derived, and the relationship of them versus the acentric parameters are studied by calculation and plot. The result indicates that the relationship of non-paraxial HSiG beam characters versus the acentric parameter is different from paraxial case. As the parameter w0/λ decrease, α→0, the far-filed divergence angle with even and odd orders approach 73.898° and 63.435°, respectively. With increasing the parameter, the waist width and M2 factor show large changes. Because of the effect of parameters, non-paraxial M2 factor can be less than 1 as well as approaching 0, which is different from paraxial case.