單石化二段式分布式回饋雷射之電流相依微波特性之物理模型建立

Abstract

我們先前的研究已展示單石化二段式分布式回饋雷射已能產生一個可調變頻率及窄線寬之微波訊號，直觀來說我們元件輸出之波長跟輸入之電流呈線性關係，由於先前相關之研究大多是在固定強度下調變輸出波段，所以其主屬雷射之間的強度變化並不會改變，但在我們的元件中是藉由調變電流改變其運作波長，和先前之研究明顯不同，在這個研究中我們試圖為其建立一個能連結其表現特性和其輸入電流之物理模型，透過其物理模型的建立及實際數據的量測的比對，我們能發現在大多數情形輸出之波長跟輸入之電流呈線性關係這個假設是可行的，但在少部分情形下，由於元件特性的不同輸出之波長跟輸入之電流呈非線性關係，在建立完這個模型之後，我們能透過模擬的方式來了解各個不同的雷射元件參數的改變對雷射本身的表現產生什麼變化，進而提供我們一個可以改良未來元件表現之範本

Our previous research has demonstrated a monolithic two-section DFB laser is cable of generating a tunable and narrow linewidth RF signal. The output wavelength shares a linear relation with the input current, due to previous study doesn’t alter the output power while they tune the wavelength, the power ratio between the slave and master laser doesn’t change. But because our monolithic device depends on tuning current to tune the output wavelength, unlike previous studies, we are not able to maintain a fixed power ratio between the slave and master laser. In this thesis we try to establish a physical model to link the relation between the input current and output property of the laser, through physical model constructing and actual data measurement, by comparing the results we find that the assumption of linear relation between current wavelength is correct for most case, but sometimes due to different operating condition the relation becomes nonlinear. With the help of this model we are able to see the effect of changing some important laser parameters, therefore providing us a blueprint of how to improve our laser performance in future laser design.