本論文將利用四波混頻分析來量測量子點半導體雷射受到外部光回饋時的本質參數，進而探討半導體雷射之動態行為。
為了探討雷射對外部微擾下四波混頻的特性，我們推導了未受擾動以及受光回饋擾動下的量子點半導體雷射模型，得出其解析解，並將這些理論模型仔細地和數值模擬的結果作驗證比對。
接著將簡化後的速率方程式模型進行光回饋下量子點半導體雷射的四波混頻分析，其中我們討論了不同本質參數和不同光回饋條件下再生訊號頻譜和調幅訊號頻譜的變化。
實驗上我們藉由不同的調頻頻率下再生訊號和調幅訊號頻譜與理論模型進行擬合，便可以同時得到多個雷射本質參數，而不同光回饋條件下單模量子點半導體雷射的本質參數變化也可在四波混頻分析下討論。
實驗結果中展示了光回饋下的線寬增益係數在光回饋強度增加會有上升的現象，而光強度減弱時線寬增益係數會隨著降低，而且有機會低於無光回饋時的原始值。
我們也分別討論在長、短外部共振腔區域下的回饋光相位造成參數變化，
其中若將回饋光距離操作在短外部共振區域時會使線寬增益係數的變化更加明顯。
於結果中，當將光回饋距離固定在 2.0 公分，調變適當的光回饋強度及相位能使線寬增益係數下降至原始值的六成左右，這個現象可以用在降低光通訊的啾頻效應。

We have successfully applied the four-wave mixing (FWM) analysis on a quantum-dot (QD) semiconductor laser subject to optical feedback. The simplified rate equation model of the QD lasers for the FWM analysis is derived and verified. From the theoretical analysis, the characteristic behaviors of the regenerative and amplitude modulation spectra of the FWM signals are predicted by different intrinsic parameters and feedback conditions. By fitting the experimentally obtained regenerative signals and amplitude modulation signals with the respective curves from the rate equations which calculated at different detuning frequencies, the impacts on the QD lasers with different feedback conditions are extracted qualitatively and quantitatively. Moreover, the fitting results show that the linewidth enhancement factor  of QD laser has a reduction of up to 40 % from its free-running value, resulting in the reduction of the chirp in optical communication.

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