高功率單葉型操作之量子點雷射陣列

Abstract

本論文利用脊狀波導陣列及含吸收區域與否，來嘗試達到在高功率輸出的操作下，維持平行於主動層接面方向上的單葉型遠場圖樣。脊狀波導陣列以啁啾式波導結構為基礎，將不同陣列模態之模態增益予以區隔，並加入吸收區域使模態增益差異更大，讓雷射更容易操作在基態陣列模態上。 本實驗在砷化銦量子點雷射(波長均在1.3μm左右)上，達到共振腔1mm的雷射陣列(未含吸收區域)，其在0.94W的輸出功率下，維持遠場半高寬6.9°(同量測條件下，寬波導遠場半高寬為9.3°)；共振腔1mm(含吸收區域)，在0.764W的輸出功率下，維持遠場半高寬4.8°；共振腔1.5mm(含吸收區域)，在1.85W的輸出功率下，維持遠場半高寬5.1°。

In this thesis, InAs quantum dot laser arrays are studied. The goal was to achieve high power laser output with a narrow and single lobed far field distribution in the horizontal (in plan) direction. We used coupled waveguide designs with various stripe distributions to control the output mode of the laser. The result was compared with that of a broad area cavity. Using combinations of a chirped distribution of ridge-waveguides and chirped absorption region in the waveguides, we are able to obtain single lobe far field with excellent angular distributions. The lasers all emitted at 1.3μm. We have achieved single lobe operation in several array designs. With a 1mm cavity length, we obtained a far field pattern with a full width at half maximum (FWHM) of 6.9°at 0.94W output power (no absorption region). With absorption regions in each stripe, we were able to obtain a FWHM of 4.8°at 0.764W for a cavity length of 1mm and a FWHM of 5.1°at 1.85W output power for a cavity length of 1.5mm