本篇論文利用軸稜錐透鏡以及聚焦透鏡的組合使泵源光束行形成瓶型光束(bottle beam)，使輸出光的雷射帶有軌道角動量(Orbital Angular Momentum, OAM)，且藉由不同位置通過Yb參雜 的晶體Yb: YAB，使系統產生不同拓樸電荷的光學渦流。且利用ABCD law的運算模擬出兩面鏡產生光時在晶體上的光斑大小(Spot size)，最後再利用馬赫-曾爾德干涉儀(Mach-Zehnder interferometer)以及對輸出光型變化運算可確認模態，確認確實為拉蓋爾-高斯模態(Laguerre Gaussian mode)，也就是光學渦流。

In this study, we use axicon lens and lens to produce a bottle beam as a pumping source. Therefore, the output of the laser system has the Optical Angular Momentum (OAM) characteristic. Because of the bottle beam’s characteristic, pumping source will change with different position. So, we can change input beam to make Optical Vortex tunable. We set this experiment on the Yb: YAB crystal and use two-element cavity to generate a laser with OAM. After finishing our experiment, we use Mach-Zehnder interferometer to observe output phase distribution. Finally, we generate an optical vortex laser with a tunable topological charge (l).

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