Observation of optical feedback dynamics in single-mode terahertz quantum cascade lasers: Transient instabilities
Observation of optical feedback dynamics in single-mode terahertz quantum cascade lasers: Transient instabilities
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DOI：
10.1103/physreva.103.033504
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发表时间：
2021-03-08
影响因子：
2.9
通讯作者：
Rakic, Aleksandar D.
中科院分区：
文献类型：
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作者：
Qi, Xiaoqiong;Bertling, Karl;Rakic, Aleksandar D.
我们提供了光反馈下太赫兹（THz）量子级联激光器（QCL）瞬态不稳定性（ti）的实验证据，与广泛接受的太赫兹量子级联激光器（QCL）在反馈下超稳定的说法形成对比。其表现为激光发射功率或终端电压的周期性振荡，振荡频率随反馈的增加而增加。太赫兹量子激光器中没有弛豫振荡和低线宽增强因子，使其成为探索半导体激光器中与外腔相关的动力学的独特平台。这项工作为基于这些ti的太赫兹传感和成像模式开辟了一条途径，与使用激光反馈干涉测量的现有方法相比，它大大降低了复杂性。
We provide an experimental evidence of transient instabilities (TIs) in a terahertz (THz) quantum cascade laser (QCL) under optical feedback, in contrast to the widely accepted claim that THz QCLs are ultrastable against feedback. The TIs appear as periodic oscillations in emitted power or terminal voltage of the laser with an increasing oscillation frequency as feedback increases. The absence of relaxation oscillations and low linewidth enhancement factor in THz QCLs makes them a platform uniquely suitable for exploring external-cavity-related dynamics in semiconductor lasers. This work opens a pathway to a THz sensing and imaging modality based on these TIs, which has much reduced complexity compared to existing approaches using laser feedback interferometry.