色散透镜系统中宽带厄米-高斯光束的焦移  

Focal shift of polychromatic Hermite-Gaussian beams in dispersion lens system

作　　者：谢鹏飞 彭润伍[1] 谢海情[1] XIE Pengfei;PENG Runwu;XIE Haiqing(Department of Physics and Electronic Science, Changsha University of Science and Technology, Changsha 410114, China)

机构地区：[1]长沙理工大学物理与电子科学学院,长沙410114

出　　处：《激光技术》2019年第3期406-410,共5页Laser Technology

基　　金：国家自然科学基金资助项目(61404011);湖南省自然科学基金资助项目(2015JJ3001)

摘　　要：为了了解带宽对厄米-高斯光束的聚焦特性和焦移的影响,采用衍射积分推导了TEM_(11)模和TEM_(22)模厄米-高斯光束通过受光阑限制色散透镜的传输公式,并利用数值计算对聚焦光强分布进行了研究,分析了带宽对两种模式焦移的影响。结果表明,TEM_(11)模和TEM_(22)模厄米-高斯光束的焦移量都会随带宽增大而增大,但两者的大小依赖相对带宽;当相对带宽小于0.25时,TEM_(22)模焦移量大于TEM_(11)模焦移量,然而相对带宽大于0.25时,后者会稍大于前者;带宽变化使TEM_(22)模轴上光强主极大和次极大发生消长,从而引起轴上光强极大位置发生跃变。该研究结果对宽带厄米-高斯光束的应用具有一定的参考价值。In order to know effect of bandwidth on the focused properties and focal shift of Hermite-Gaussian (H-G) beam, propagation formula of H-G beams passing through a dispersion lens system with polychromatic TEM11 mode and TEM22 mode was obtained by using diffraction integral. The focused intensity distribution was studied by numerical calculation. The effect of bandwidth on focal shift of both modes were analyzed. The results show that the focal shifts of H-G beams with TEM11 mode and TEM22 mode increase with the increase of the bandwidth and depend on the relative bandwidth. Focal shift of TEM22 mode is greater than that of TEM11 mode when relative bandwidth is smaller than 0.25 whereas the latter is somewhat greater than the former when relative bandwidth exceeds 0.25. The principle maximum intensity and the secondary maximum intensity of TEM22 mode on the axis compete each other with the vary of bandwidth and then the axial primary maximum intensity transits from one place to another. The results are helpful for further application of the polychromatic H-G beams.

关 键 词：激光物理 焦移 色散透镜 带宽 

分 类 号：O436[机械工程—光学工程]