具有橢圓環面射型雷射中的新月波特性之研究

Abstract

在這篇論文中，我們在表面具有橢圓環的垂直共振腔面射型雷射中觀察到新月波的形成，並進一步研究新月波對雷射特性的影響。我們使用一般的砷化鎵垂直共振腔面射型雷射，並以聚焦離子束在垂直共振腔面射型雷射的表面蝕刻出橢圓環的結構，透過量測雷射近場的量測系統，隨著提高電流注入，觀察到樣品達到雷射操作條件時，近場具有新月狀的分布，藉由非線性薛丁格方程在線性模態的位能井中的計算可以模擬得到相對應的結果，而透過量測雷射遠場的量測系統，可以進一步了解新月波對雷射輸出特性的影響。利用將新月波和垂直型共振腔面射型雷射的結合，預期可以在未來達到對雷射的模態以及遠場特性調控的效果。

In this thesis, we successfully observe the formation of crescent waves in VCSEL with elliptical ring on its surface. We further study the properties of laser influenced by crescent waves. We use conventional GaAs-based VCSEL, and etch an elliptical ring structure on its surface by focused ion beam. We measure the near field image of VCESL. As the injection of current getting higher, when our sample reach the lasing threshold, optical field become crescent-shape distribution. We can simulate and get the answer similar to experiment result by the calculation of nonlinear Schrödinger equation in linear mode potential. We can further find out the output profile of laser influence by crescent waves through far filed measurement system. In future, we expect the mode profile and the output characteristic of laser can be tunable via the combination of crescent waves and VCSEL.