氧化型與佈植型之垂直共振腔面射型雷射之特性研究

Abstract

本論文主要是研究 GaAs垂直共振腔面射型雷射的溫度特性、近場分析、高頻調變以及可靠度分析。用於此研究的雷射有兩種不同的結構：一是氧化型電流侷限結構，一是質子佈植型電流侷限結構。 由溫度相關雷射輸出功率對注入電流的關係，我們發現gain off-set effect，這是只會發生在面射型雷射的獨特特性。由此看來，面射型雷射的特性表現與雷射的操作條件有著強烈的相關性。 由近場光學的結果來分析，氧化型電流侷限結構比質子佈植型電流侷限結構有較好的電性與光學特性。我們發現雷射的調變能力會受到寄生阻抗效應 (parasitic impedance effect) 的影響而且我們由relaxation frequency計算出光子在氧化型電流侷限結構與質子佈植型電流侷限結構的生命週期分別為5.8 ps 與6.2 ps。最後，我們也設計了雷射可靠度實驗，並且分析雷射損壞 (degradation) 可能的物理機制

In this thesis, we investigated the characteristics of GaAs based vertical cavity surface emitting lasers (VCSELs) including temperature dependent light verse power (L-I) curves, near-field profiles, high speed modulation, reliability test and failure analysis. We analyze two types of lasers structures experimentally. One is oxide-confinement and the other is proton-implantation. The temperature dependent L-I curves shows the gain off-set effect, which is the unique characteristic of VCSELs. As result, the performance of VCSELs strongly depends on the operating condition. From the near-field profiles, oxide-confined VCSEL has better current and optical confinements than proton-implanted VCSEL. The measured modulation response showed that the relaxation frequency of laser is affected by the parasitic impedance effect and the photon lifetime of oxide-confined and proton-implanted VCSELs are estimated from the modulation response to be about 5.8 ps and 6.2 ps respectively. We also conducted a constant current experiment of the reliability test, and analyzed the possible failure mechanisms of the degradation of lasers.