Large Astigmatic Laser Cavity Modes and Astigmatic Compensation
Teng-De Huang (黃騰德)1*, Ting-Hua Lu (陸亭樺)1
1Department of Physics, National Taiwan Normal University, Taipei, Taiwan
* Presenter:Teng-De Huang (黃騰德)
We experimentally verified that anisotopic (astigmatic) Hermite-Gaussian (HG) modes can be generated from a hemi-cylindrical cavity and transformed into Laguerre-Gaussian (LG) modes by using an extra-cavity plano-convex cylindrical lens that can modify different beam divergence angle in the x-z and y-z planes. By controlling the off-axis pumping and the angle of the extra-cavity cylindrical lens, we observed a variation in the laser patterns. We analyzed several additional relationships under different conditions. All experimental results corresponded with the theoretical analysis, and the role of the hemi-cylindrical cavity can be completely understood by comparing the theoretical and experimental results.

Keywords: optical vortices, hemi-cylindrical cavity, astigmatism, Laguerre-Gaussian mode