半導體微共振腔之光學特性

Abstract

本論文主要目的為研究半導體微共振腔之光學特性。首先推導了量子井激子的光學響應。接著，以轉移矩陣法，分析共振腔模態以及不同結構的微共振腔特性。當加入量子井後，共振腔模態和激子的耦合會形成電磁極化子模態，而在頻譜上產生拉比分裂的特性。針對電磁極化子模態，分別探討入射角度、耦合強度、量子井數目以及激子頻率調變所產生的影響。另外，也會討論簡單的非線性性質，利用Fabry-Perot模型與平均場方法推出解析解，以此來討論當入射光場強度改變時，對微共振腔內部光場強度以及吸收之影響。由結果可發現，共振腔模態與激子在色散關係圖中的交點耦合強度最強，而隨著入射角度、量子井數目或激子頻率的改變，都會讓電磁極化子模態的特性變的不明顯。此外，入射光場強度變大時，也會造成相似結果。

The main purpose of this thesis is to investigate the optical properties of semiconductor microcavities. First, the optical response of quantum well excitons is derived. Base on the transfer matrix method, characteristics of the cavity mode and microcavities which have different structures are analysed. After the influence of quantum well is considered, the coupling of the cavity mode and excitons forms the polariton modes which results in the Rabi splitting in the spectrum. The effects on the polariton modes in terms of incident angle, coupling strength, quantum well number and exciton modulation have been discussed. Moreover, a simple nonlinear phenomena is also considered. With the Fabry-Perot model and the mean-field approach, an analytical solution is obtained. This is useful for studying the effect of the incident field intensity on the field intensity and the absorpsion in microcavities. According to the results, the crosspoint of the cavity mode and excitons in the dispersion relation has the most intense coupling strength. With changes of incident angle, quantum well number or exciton frequency, the properties of polariton modes will become less significant. Besides, if the incident field intensity turns stronger, the similar results will be found.