半導體量子線雷射之研究

Abstract

從理論推測，量子線結構有個非常獨特的特徵，當光之電場方向不同，對於相同能階之電子其跳躍機率也會不同，此即為非等向性極化效應，本論文主要就是要探討利用S.K.模式成長之InAs量子線結構雷射的特性，研究量子線本身之非等向性極化效應的影響。為此我們製作了兩組不同共振腔方向之量子線雷射二極體，分別為共振腔垂直與平行量子線延伸方向之雷射，之後再分別量測此兩組雷射之變溫L-I曲線、變溫雷射發光頻譜、以及量子線結構雷射試片之變溫偏極化光激發光頻譜，我們研究的重點主要是放在量子線本身之非等向性極化效應最後如何影響量子線結構雷射之雷射基本特性。 實驗結果證實量子線之非等向性極化效應的確改變了此兩組不同共振腔方向之量子線雷射二極體的基本雷射特性，兩者的起始電流大小差異頗大，雷射發光波長也非常不一致。 另外在此研究中，我們還發現一些有趣的現象，並與以討論分析之，未來研究方向將探討如何利用這些現象於元件應用中，並進而製作相關之應用元件。

Theoretical studies have reported that the 1-D valence subbands cannot be labeled as heavy-hole (hh) band and light-hole (lh) band because the hh and lh bands are strongly mixed. This mixing causes strong polarization anisotropy in the emission and absorption spectra with respect to the direction of electric field parallel or perpendicular to the wire. In this study, we mainly investigated the effect of the polarization anisotropy in quantum wires (QWrs) lasers. For this, two kinds of contact stripes with different direction were made： One with the contact stripes aligned to , and another with the contact stripes aligned to .Moreover, the direction of the QWrs is along . In order to study the effect of the polarization anisotropy in QWrs lasers, the temperature dependent L-I curve, Laser spectrum, and polarization dependent photoluminescence were measured. The results did show the existing of the effect of the polarization anisotropy in our QWrs lasers. The threshold current and laser emission wavelength were totally different for the QWrs Laser with different contact stripes direction. Besides, other interesting and strange phenomena were observed in our study and they were discussed in later chapter. In the future, we hope these interesting and strange phenomena could be used for the device application.