高發光效率之氮化鎵二維面射型光子晶體分散回饋式雷射

Abstract

本計劃主要目的在於開發與研究氮化鎵二維面射型光子晶體分散回饋式雷射。將利用本實驗室所 發展之現有與研發中之製程技術，包括：垂直微共振腔二極體、發光二極體及a-plane氮化鎵的磊晶技 術等方式將光子晶體製作於這些結構上並且達到雷射的操作模式。其中藉由設計不同的孔洞大小與週 期可以使光子晶體反射特殊波長的光譜，因此可以取代DBR，同時減少熱效應並且達到磊晶及製程簡 化的目的。而非極化(non-polar)Ⅲ-Ⅴ化合物半導體最大的好處在於它能有效消除極化結構存在的內建 電場，有效的降低Quantum Confined Stark Effect (QCSE)並且免除內建電場對能帶的影響，因此光子晶 體結構結合此種材料對於未來元件操作效能的提升有很大的潛力。本實驗室再利用理論計算及模擬軟 體，設計具有下DBR的光子晶體結構。藉由減少共振腔長度及減少下DBR堆疊數，此方法不但可以使 製程與磊晶難度簡化，更可以達成單一雷射的光子晶體元件。

The main objective of this project is to develop and study high efficiency GaN-based two-dimensional surface-emitting photonic crystal distributed-feedback (2D SEPC DFB) lasers. We’ll combine our previous experience in fabricating GaN-based vertical cavity surface emitting lasers, micro-cavity light emitting diodes, GaN nanorods, and a-plane GaN epitaxy to tailor and optimize the current injection-type GaN-based two-dimensional surface-emitting photonic crystal distributed-feedback (2D SEPC DFB) lasers. Especially, photonic crystal structure, which can reflect the special wavelength we designed, thus can replace the DBR structures, should reduce the thermal effect, and simplify the epitaxial and fabrication processes. In addition, using non-polar GaN can reduce the built-in electrical field in the polar structure and reduce Quantum Confined Stark Effect (QCSE). Photonic crystal structure combined with this material has a great potential to enhance performance of the future devices. We also calculate and simulate the photonic crystal structure with bottom DBR by FDTD to design and fabricate the photonic crystal lasers emitting single mode and simplified the epitaxial and fabrication process by reduced cavity length and less pairs of DBR.