量子點光子晶體面射型雷射

Abstract

本論文成功製作出可在室溫操作的光激發砷化銦量子點光子晶體面射型雷射，操作溫度甚至可高達70度，雷射的關鍵就是在於光子晶體孔洞的蝕刻深度，孔洞深度關係到耦合的強弱，要有足夠強的耦合才能達到雷射條件。我們使用的試片是主動層為自聚型的砷化銦量子點，有著特殊設計磊晶結構，其上下披覆層不對稱，將上披覆層減薄至剩下200 nm，可使得光場進入到光子晶體共振腔的強度增強，增加耦合強度。接著有對於不同結構的光子晶體雷射進行分析，其中包含了週期、孔洞深度與填充率。利用周期的不同，同一片試片上可以製作出波長範圍60 nm的面射型光子晶體雷射，藉由改變孔洞深度與填充率，可以降低閥值能量與提升斜率效率，目前做到最低的閥值能量為1.88 kW⁄(cm^2 )。

In this thesis, InAs quantum-dot photonic crystal surface emitting lasers (PCSELs) were fabricated and room-temperature lasing emissions were demonstrated by optical pumping. The operating temperature can be as high as 70oC.The etching depth of PC holes is the key process parameter for efficient diffraction coupling and the resulting lasing emissions. The active layer of ours elected epitaxial laser samples is self-assembly InAs quantum-dot(QD).This sample has a special design that is upper cladding and lower cladding layers are asymmetric. This special design enhances the intensity of the light entering the photonic crystal resonator and the diffraction coupling. Next, we studied PC structures, including period, depth of holes and filling factor. We can fabricate PCSELs with different wavelengths in the range of 60 nm by changing the PC period. By changing the parameter for depth of holes and filling factor, we can reduce the threshold and improve the slope efficiency. Up to now the lowest threshold is 1.88 kW⁄(cm^2 ).