强激光与粒子束, 2003, 15 (8): 733, 网络出版: 2006-04-28
用环围功率法研究双曲正弦高斯光束的焦移
Focal shift in Sinh-Gaussian beams by using the encircled-power method
摘要
从Collins公式出发研究了无光阑双曲正弦高斯光束的聚焦特性.研究发现聚焦双曲正弦高斯光束的轴上光强为零,因此Li和Wolf二人研究焦移的方法不再适用.使用环围功率法定义束宽和实际焦面,由此可以决定聚焦双曲正弦高斯光束的焦移.数值计算表明,聚焦双曲正弦高斯光束的焦移与偏心参数和菲涅耳数有关,焦移随偏心参数和菲涅耳数的减小而增大.此外,还分析了双曲正弦高斯光束的最佳聚焦问题.
Abstract
Starting from the Collins formula, focusing properties of un-apertured sinh-Gaussian beam are studied by using the encircled-power method. It is found that the axial intensity of focused sinh-Gaussian beams vanishes, so that Li-Wolf's approach to the focal shift fails. The encircled-power method is introduced to define the beam width and real focal plane of focused sinh-Gaussian beams, thus their focal shift can be determined. Numerical calculations are performed and show that the focal shift in focused sinh-Gaussian beams depends on the Fresnel number and decentered parameter, and increases by decreasing them. The optimal focusing of sinh-Gaussian beams is also analyzed.
彭润伍, 吕百达. 用环围功率法研究双曲正弦高斯光束的焦移[J]. 强激光与粒子束, 2003, 15(8): 733. 彭润伍, 吕百达. Focal shift in Sinh-Gaussian beams by using the encircled-power method[J]. High Power Laser and Particle Beams, 2003, 15(8): 733.