利用球差实现超高阶拉盖尔—高斯模式激光振荡  

Generation of Very-high-order Laguerre-Gaussian Mode from Laser Cavity with Spherical Aberration

作　　者：盛泉[1,2] 王爱华 王盟 刘俊杰[1,2,3] 史伟 姚建铨[1,2] SHENG Quan;WANG Ai-hua;WANG Meng;LIU Jun-jie;SHI Wei;YAO Jian-quan(School of Precision Instrument and Optoelectronics Engineering,Tianjin University,Tianjin,China;Key Laboratory of Optoelectronic Information Science and Technology(Ministry of Education),Tianjin University,Tiaiyin,China;Tianjin Jinhang Institute of Technical Physics,Tianjin,China)

机构地区：[1]天津大学精密仪器与光电子工程学院,天津 [2]光电信息技术教育部重点实验室,天津大学,天津 [3]天津津航技术物理研究所,天津

出　　处：《光电技术应用》2021年第5期73-76,共4页Electro-Optic Technology Application

基　　金：国家自然科学基金(61975146)资助课题。

摘　　要：基于腔内球差选模方法在端面泵浦的Nd:YVO_(4)激光器中实现了能够对角向指数m进行便捷选择的高阶LG模式激光输出,从LG模式光斑半径和能量分布的角度对实验现象进行解释,分析发现不同模式间球差引起的实际焦点偏离是实现单一LG模式运转的关键,而单一模式自身球差产生的损耗决定了该模式是否能够起振。根据理论分析,分别通过使用长焦距透镜减小球差以降低高阶模式的损耗和增加泵浦功率以提高增益,实现了角向指数m最高达到±95的超高阶LG模式输出;通过使用短焦距透镜增大球差来加强对光斑较小的低阶模式的区分度,实现了径向指数p>0的LG模式输出。High-order Laguerre-Gaussian(LG)mode output,the angular indices m of which can be tuned conveniently,is generated in an end-pumped Nd:YVO_(4) laser which has strong spherical aberration(SA)in its cavity.The experimental results are explained based on the beam radius and ring-shaped beam width of the LG mode beam.It is found that the SA-induced actual focal point displacement between different modes is essential for single high-order mode operation,while the SA and the beam width determine the loss on a certain mode and whether it can oscillate.For high-order mode operation,long-focal lens is used to decrease the SA and resultant loss on highorder modes and increase the pump power to enhance the laser gain.A maximum angular index m of±95 is obtained with radial index of p of 0.With short-focal lens to enhance the SA and corresponding mode-selecting capability,LG mode output with non-zero radial indices is obtained.

关 键 词：拉盖尔高斯模式 固体激光器 模式选择 球差 

分 类 号：TN242[电子电信—物理电子学]