雙波長切換量子點雷射

Abstract

本論文針對量子點雷射中普遍存在的激態與激發態兩種能態雷射現象做討論，以分子束磊晶成長砷化銦/砷化鎵自聚性量子點，形成量子點雷射的主動層，製作簡易的脊狀波導雷射，同時具有電流侷限與光侷限的功能，室溫下雷射波長在1.2μm(激發態)與1.3μm(基態)，實驗中，量測在不同共振腔長度與溫度下對量子點雷射特性的影響，並利用其特性，設計出兩截共振腔結構的量子點雷射，藉由控制個別共振腔中的電流，我們成功達成在量子點雷射中基態與激發態雷射的切換，並探討在不同操作情況下基態與激發態雷射發生與其互相影響的機制。

In this thesis, we have investigated the two-state lasing phenomena in quantum dot lasers. In the experiment, the self-assembled InAs quantum dot grown with molecular beam epitaxy has been used as the active layer of the laser, and the ridge waveguide structure has been fabricated for the current and optical confinement. There are two kinds of lasers with different wavelengths which are 1.3 and 1.2μm corresponding to the ground state and the excited state lasing at room temperature. By measuring the characteristics of laser cavities with various lengths and at different temperature, we could know find the influence of the cavity length and the temperature on the characteristics of quantum dot lasers. As a result, we could design the two-sectional structure of quantum dot laser cavity. The switching of the laser of the single ground state and the single excited state has been achieved by controlling the injection current in each cavity, and the 2-dimensional mapping diagram of the injection currents versus the lasing states has been shown to find out the operable condition. The operation condition would be clear based on the relation between the injection current and the lasing state.