余弦平方-高斯光束通过像散透镜的焦开关  

Focal switch of cosine-squared Gaussian beams passing through an astigmatic lens

作　　者：牟国强[1] 王莉[1] 王喜庆[1] 

机构地区：[1]西南交通大学物理科学与技术学院,成都610031

出　　处：《激光技术》2011年第4期562-565,共4页Laser Technology

摘　　要：为了研究余弦平方-高斯光束通过像散透镜后的焦开关现象,应用Collins公式推导出了聚焦余弦平方-高斯光束轴上光强分布的表达式,通过数值运算得到了像散参量对轴上光强分布的影响。结果表明,在给定光束参量和光束菲涅耳数的条件下,光束入射面位置不同时,余弦平方-高斯光束通过像散透镜后的相对焦移随像散参量变化而变化,确定了在此条件下,产生双焦开关时光束入射位置的范围。In order to analyze the focal switch phenomena of cosine-squared Gaussian beams passing through an astigmatic lens, the expression for the axial irradiance distribution of focused cosine-squared Gaussian beams was derived based on the Collins formula. By means of numerical calculation, effect of astigmatic parameter on the axial irradiance was obtained. The dependence of the relative focal shift on the astigmatic parameter was studied at different positions of the beam＇ s incident plane for a particular beam parameter and Fresnel number; the range of the beam＇ s incident position of dual focal switches under this condition was determined and the focal switch due to the astigmatism was interpreted.

关 键 词：激光光学 焦开关 COLLINS公式 像散 余弦平方-高斯光束 

分 类 号：O435[机械工程—光学工程]