量子點雷射在近幾年來開始蓬勃發展，主要是因為它有高溫穩定的特性，以及低的起始電流密度，可應用於光碟機讀寫頭、紅外線偵測器，以及現今最熱門的光纖通訊等方面，且因為量子點製作技術逐漸改良，使得各量子點的尺寸、均勻度有明顯的改善，得以發展性能較佳的量子點雷射。
　　目前二維侷限的量子線雷射逐漸成熟，因此，各國皆逐漸往三維侷限的量子點雷射發展。理論上，量子點雷射的臨界電流密度，受溫度與特徵溫度的影響不大，僅只有微小的變化。但是，在高溫的狀態下，載子會因為熱激發而逃脫到光侷限層窄小區域中，使得載子無法有效地被量子點所抓住，而造成臨界電流密度大幅的提高。本論文，係以理論模式探討量子點層與光侷限層分別為GaInAs與GaInAsP時，量子點在平衡態、非平衡態注入條件下，電子與電洞佔據機率達到雷射作用時之最小表面密度以及量子點尺寸變異等因素對臨界電流密度的影響，在模擬結果中，在非平衡態注入量子點，可以得到在80K時，臨界電流密度只有4~5安培/平方公分，以及和實驗做出來的量子點雷射做相關的比較。

　　The technology of quantum dot laser has attracted great attention recently due to its excellent properties of high temperature and the low threshold current density. Its applications include the header of read-write of the CD-ROM drive, infrared remote sensing the optical fiber and communication and so on. Due to significant progress in manufacturing technology of quantum dot layer structure, the size and uniformity of quantum dots have achieved great improvement. Consequently, development of high performance quantum-dot laser becomes possible.
　　Recently, the techniques of quantum-well laser with two-dimensional confinement have already well developed. In the near future, the quantum-dot laser with three-dimensional confinement certainly becomes the next focus of high technology in many countries. Theoretically, the effect of the temperature and characteristic temperature on the threshold current density of quantum-dot laser is very small. However, at higher temperature, the carriers will easily by thermally exciting to the narrow region of optical confinement layer (OCL). In other words, it becomes more difficult to catch the carriers by the quantum dots. Consequently, the threshold current density of quantum dot will rise substantially. In this thesis,GaInAs and GaInAsP are selected as material of quantum dot and optical confinement layers, respectively. We focus on the state of equilibrium, non-equilibrium injections. The effects of the probability of electron and hole, the minimum of surface density, and the derivation in size and uniformity of quantum dot on the threshold current density are evaluated and discussed. The result show that on the state of non-equilibrium injections, we get 4~5 A/cm2 of threshold current density at 80K, and the relationship compare with the quantum dot laser of experiment.

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