以自然氧化層製作高性能InGaAs/GaAs/AlGaAs折射波導半導體雷射

Abstract

在本篇論文中,首先我們用有效折射方法去模擬橫向單一模態操作雷射的 設計區域.並由此計算其對應的近場光強度分布.然後在實驗部份,我們藉 MBE長晶,在活化層上方長一層高鋁含量 AlGaAs,然後做曝光顯影蝕刻形成 條紋,將此層部份曝露出.放入高溫爐管氧化.將AlGaAs氧化成.此的電流阻 隔性很好.且其折射率只有1.6.和量子井的折射率3.5相差很多.形成很好 的光阻隔效應(我們成功製作出波長0.85微米AlGaAs/GaAs 1微米寬條狀折 □ 瘢伄p射,其臨界電流28毫安.能單一橫向模態操作.在偏壓電流100毫安 時,其每面輸出功率為40毫瓦,外部量子效率值達到0.9.兩面皆鍍上高反射 率膜,一方面降低臨界電流,增加斜率效率值,另一方面改善可靠度.在波 長0.98微米 GaAs/InGaAs 折射波導雷射中,製作出臨界電流26毫安的1.5 微米寬條狀雷射.能單一橫向模態操作.在偏壓電流100毫安時,其每面輸出 功率為35毫瓦,外部量子效率值達到0.85.兩種雷射的特性溫度均在160K以 上,顯示對溫度改變不大,其遠場角度水平和垂直大都為:10度和30度. In this thesis we firstly demonstrate simulation lateral single mode design curves and related near field patterns using four layer slab waveguide model. Secondly we demonstrate the fabrication of AlGaAs (0.85(m) and InGaAs (0.98(m) lasers with buried native oxide () layer above active region. For 0.85(m AlGaAs/GaAs lasers of 1(m-wide aperture, the thresholdx 瘢rent is 28mA for 250(m-long cavity and maximum power is 40mW per facet on CW operation at room temperature at 100mA bias current. The slope efficiency of 4(m-wide aperture is about 0.7W/A per facet, corresponding to an external quantum efficiency of 0.9. The characteristic temperature of 4(m-wide aperture is about 184K at 10 C-50 C. For 0.98(m GaAs/InGaAs lasers of 1.5(m-wide aperture, the threshold current is 26mA for 250(m-long cavity and maximum power is 25mW per facet on CW operation at room temperature at 80mA bias current. The slope efficiency of 1.5(m- wide aperture is about 0.67W/A per facet, corresponding to an external quantum efficiency of 0.85. The of 1.5(m-wide aperture is about 150K at 10 C-85 C. The emission spectrum of these lasers are nearly single mode operation. The ratio of far-field pattern is all about 1:3 for parallel and perpendicular direction. We also demonstrate the HR/HR coating of AlGaAs native oxide lasers. It improves the slope efficiency and reduces the threshold current shown in experiment data.