被光阑像散透镜聚焦高斯-谢尔模型光束轴上的光谱开关

从部分相干光的传输理论出发,研究了高斯-谢尔模型光束通过光阑像散透镜聚焦的光谱异变和光谱开关。研究表明,在考虑像散的情况下,聚焦场轴上也会出现光谱异变和光谱开关。光谱异变和光谱开关不仅与空间相关性、截断参量、菲涅耳数和源光谱谱宽有关,透镜像散对光谱异变和光谱开关也会产生影响。通过数值计算结果,重点对透镜像散对光谱移动和光谱开关的影响进行了分析。与无像散情况相比,像散会使出现光谱开关的临界位置发生变化,当像散较大时出现光谱开关的临界位置明显向几何焦面移动,特别是当像散增加到一定数值时,光谱开关会消失。

On-Axis Spectral Switches of Gaussian Schell-Model Beams Focused by an Astigmatic Aperture Lens

From the propagation theory of partially coherent light,spectral anomalies and spectral switches of Gaussian Schell-model beams focused by an astigmatic aperture lens are studied.It is shown that,in the case of the astigmatism of the lens,spectral anomalies and spectral switches may also take place on axial points of the focused field.Spectral anomalies and spectral switches depend on spatial coherence,truncation parameter,Fresnel number and bandwidth of the source,but the astigmatism of the lens also affects them.Numerical calculation results are given to illustrate how the astigmatism of the lens affects the spectral shifts and switches.Compared with the astigmatism-free case,the astigmatism can change the critical position where the spectral switch takes place.And the shifts of critical position of the spectral switch take place remarkably to the geometrical focal plane when the astigmatic parameter is large enough.In particular,the spectral switch vanishes as the astigmatic parameter is larger than a certain value.