摘要
利用不同阶拉盖尔-高斯(LG)模式激光具有不同光束尺寸的特性,在激光谐振腔内使用短焦距透镜引入球差,使各阶LG模式激光的空间光路发生分离,从而实现对高阶横模的选择并产生高阶LG模式涡旋激光输出。通过对高阶LG模式激光的聚焦特性和透镜球差进行分析计算,给出了高阶LG_(0,±m)模式涡旋激光的角向指数(m)随谐振腔参数变化的理论模型。搭建端面泵浦的1064 nm Nd∶YVO_(4)激光器开展了实验研究,在2.06 W泵浦功率下获得了角向指数可便捷调控且m最高可达到280的超高阶LG_(0,±m)涡旋激光输出。实验产生的超高阶涡旋激光具有良好的功率和模式稳定性,模式变化规律与理论计算结果相符。通过增加泵浦功率或优化泵浦交叠以提高激光增益,理论上可以产生任意高阶的涡旋激光输出。研究结果为超高阶LG模式涡旋激光的产生提供了参考。
Objective Optical vortices in the Laguerre-Gaussian(LG)mode that have a unique hollow intensity profile and non-zero orbital angular momentum are highly significant for various applications.The LG mode laser can be generated using external-cavity devices,such as holograms or cylindrical lens pairs,to transform a Hermite-Gaussian beam into a LG beam,or using the intracavity,where the intracavity components are utilized to preferentially oscillate the certain high-order modes within a laser resonator.In comparison to the external-cavity approaches,intracavity approaches typically yield superior power handling,beam quality,and conversion efficiency.However,there are very few demonstrations regarding high-order LG mode laser oscillations with angular indices(m)beyond 30.The main challenge is that the beam patterns of the very-high-order mode lasers become highly complex,which makes it difficult to fabricate mode-selecting elements with a sufficient accuracy to precisely manage the loss and gain of a certain mode.In this study,we demonstrate the generation of an ultra-high-order LG mode output based on mode selection enabled by intracavity spherical aberration(SA).By calculating the focusing behavior of the high-order LG mode beam and the SA of the intracavity lens,the relationship between the angular indices m of the high-order LG_(0,±m)vortex laser and the cavity parameters is determined.In the experiment,the ultra-high-order LG_(0,±m)vortex lasers with tunable angular indices m of up to 280 are obtained with an end-pumped Nd∶YVO_(4)laser at a wavelength of 1064 nm,under an incident diode pump power of only 2.06 W.Methods The experimental arrangement of the laser that generates the ultra-high-order LG mode output is depicted in Fig.1.Two lenses,L1 and L2,with focal lengths of f_(1)=150 mm and f_(2)=51.8 mm,respectively,are inserted into the cavity of an end-pumped Nd∶YVO_(4)laser to collimate the beam and introduce SA for mode selection.The laser is pumped by a fiber-coupled diode laser at 878.6 nm,with a pump
作者
王爱华
李锦辉
盛泉
耿婧旎
付士杰
史伟
姚建铨
Wang Aihua;Li Jinhui;Sheng Quan;Geng Jingni;Fu Shijie;Shi Wei;Yao Jianquan(School of Precision Instrument and Opto-Electronics Engineering,Tianjin University,Tianjin 300072,China;Key Laboratory of Opto-electronic Information Technology,Ministry of Education,Tianjin University,Tianjin 300072,China;Chengxian College,Southeast University,Nanjing 210088,Jiangsu,China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2023年第11期249-254,共6页
Chinese Journal of Lasers
基金
国家自然科学基金(61975146,62105240,62075159)。
关键词
激光光学
拉盖尔-高斯模式
涡旋激光
模式选择
高阶横模
球差
laser optics
Laguerre-Gaussian mode
vortex laser
mode selection
high-order transverse mode
spherical aberration
