Asryan Levon V
Opt Lett. 2017 Jan 1;42(1):97-100. doi: 10.1364/OL.42.000097.
The modulation bandwidth of double tunneling-injection (DTI) quantum dot (QD) lasers is studied, taking into account noninstantaneous pumping of QDs. In this advanced type of semiconductor lasers, carriers are first captured from the bulk waveguide region into two-dimensional regions (quantum wells [QWs]); then they tunnel from the QWs into zero-dimensional regions (QDs). The two processes are noninstantaneous and, thus, could delay the delivery of the carriers to the QDs. Here, the modulation bandwidth of DTI QD lasers is calculated as a function of two characteristic times (the capture time from the waveguide region into the QW and the tunneling time from the QW into the QD ensemble) and is shown to increase as either of these times is reduced. The capture and tunneling times of 1 and 0.1 ps, respectively, are shown to characterize fast capture and tunneling processes; as the capture and tunneling times are brought below 1 and 0.1 ps, the bandwidth remains almost unchanged and close to its upper limit.
研究了双隧穿注入（DTI）量子点（QD）激光器的调制带宽，其中考虑了量子点的非瞬时泵浦。在这种先进类型的半导体激光器中，载流子首先从体波导区域被捕获到二维区域（量子阱[QW]）；然后它们从量子阱隧穿到零维区域（量子点）。这两个过程是非瞬时的，因此可能会延迟载流子向量子点的输送。在此，DTI量子点激光器的调制带宽作为两个特征时间（从波导区域捕获到量子阱的时间以及从量子阱隧穿到量子点集合的时间）的函数进行计算，结果表明，随着这两个时间中的任何一个时间的减少，调制带宽都会增加。捕获时间和隧穿时间分别为1皮秒和0.1皮秒时，表明具有快速捕获和隧穿过程；当捕获时间和隧穿时间降至1皮秒和0.1皮秒以下时，带宽几乎保持不变且接近其上限。
