GSMBE生长的非均匀多纵模量子点激光器

Inhomogeneously Multi-Longitudinal-Mode Lasing Quantum-Dot Lasers Grown by GSMBE

报道了InAs/GaAs量子点激光器GSMBE生长,激光器器件有源区包含了层叠的5层InAs量子点微结构。AFM显微图像显示相同生长条件下的未覆盖表层量子点样品呈现出不均匀的多模尺寸分布。制作了脊条宽为6μm,腔长为1.5 mm的未镀膜激光器器件,器件室温连续工作的最大输出功率达到51.1 mW(单面),最高工作温度70℃。激光光谱包含一系列非均匀的多纵模簇,且随着电流的增加,纵模簇个数也增加。经分析认为,光谱的这一不同于常规半导体激光器的性质是由量子点的非均匀性以及量子点之间互不关联性导致的,是多个互相无关联的不同特性激光的集体行为。

InAs/GaAs quantum-dot lasers grown by GSMBE are reported. Laser structures have five layers of InAs quantum dots in the active region. Uncapped quantum-dot samples grown at same condition as lasers exhibit multi-mode size distribution revealed by AFM. The laser devices were fabricated with 6 μm-wide ridge and different cavity lengths. These devices can all operate under CW condition up to the temperature of 70 ℃, and its maximum output power is 51.5 mW at room temperature （single facet）. The emission spectra consists of several groups of multiple longitudinal modes. As injection current increases, the number of groups increases. It is considered this different feature of emission spectra unlike conventional QW lasers results from non-uniformity and non-interactivity of quantum-dots in the laser active region. The quantum-dot laser behaves as a collection of independent lasers.