Simple Nd:YAG laser generates vector and vortex beam  

作　　者：方志强 姚瑶 夏克贵 李建郎 

机构地区：[1]Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences

出　　处：《Chinese Optics Letters》2015年第3期51-54,共4页中国光学快报（英文版）

摘　　要：We report a simple Nd：YAG laser that emits radially polarized beam with helical wavefront. The laser cavity consists of a piece of laser crystal and a plane output coupler, and there is no additional polarization component inside it. The pump light is converted into annular profile through de-focal coupling into a multi-mode fiber. For the continuous-wave （CW） operation, the laser emits radially polarized vortex beam, and it is observed that the helical wavefront of the laser beam is switched from right handedness to left handedness when the output coupler is tilted slightly. For the Q-switched operation under the insertion of a Cr^4＋：YAG saturable absorber inside the cavity, we obtain radially polarized outputs with left-handedness helical wavefront. By tilting the laser crystal slightly, the laser output switches to azimuthal polarization at pump power larger than 4.5 W and left-handedness helical wavefront of laser beam is preserved.We report a simple Nd：YAG laser that emits radially polarized beam with helical wavefront. The laser cavity consists of a piece of laser crystal and a plane output coupler, and there is no additional polarization component inside it. The pump light is converted into annular profile through de-focal coupling into a multi-mode fiber. For the continuous-wave （CW） operation, the laser emits radially polarized vortex beam, and it is observed that the helical wavefront of the laser beam is switched from right handedness to left handedness when the output coupler is tilted slightly. For the Q-switched operation under the insertion of a Cr^4＋：YAG saturable absorber inside the cavity, we obtain radially polarized outputs with left-handedness helical wavefront. By tilting the laser crystal slightly, the laser output switches to azimuthal polarization at pump power larger than 4.5 W and left-handedness helical wavefront of laser beam is preserved.

关 键 词：Laser beams POLARIZATION Pumping (laser) Saturable absorbers Vortex flow WAVEFRONTS 

分 类 号：TN24[电子电信—物理电子学] O436.3[机械工程—光学工程]