Discrete mode tuning in terahertz quantum cascade lasers.
Discrete mode tuning in terahertz quantum cascade lasers.
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DOI：
10.1364/oe.20.00b306
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发表时间：
2012-12
期刊：
影响因子：
3.8
通讯作者：
S. Chakraborty;O. Marshall;Chen-Wei Hsin;M. Khairuzzaman;H. Beere;D. Ritchie
中科院分区：
文献类型：
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作者：
S. Chakraborty;O. Marshall;Chen-Wei Hsin;M. Khairuzzaman;H. Beere;D. Ritchie
采用全息设计的非周期性分布反馈光栅作为多谐振滤波器，嵌入到现有的法布里-珀罗（FP）太赫兹（THz）量子级联激光器（QCL）腔内。通过平衡滤波器谐振和FP腔的反馈强度，系统能够实现高度的单模选择性，对驱动电流的变化敏感。多模QCL工作在2.9太赫兹，从而修改，以实现纯电子离散调谐跨越160 GHz的平均调谐分辨率为30 GHz。将相同的多谐振滤波器应用于增益峰值在2.65和2.9 THz左右的QCL，导致双模激光发射，其电控频率间隔在190和267 GHz之间。通过观察激光模式的发散微调，实验证实了相敏模式选择机制。
A holographically designed, aperiodic distributed feedback grating is used as a multi-resonance filter and embedded within an existing Fabry-Pérot (FP) terahertz (THz) quantum cascade laser (QCL) cavity. Balancing the feedback strengths of the filter resonances and the FP cavity creates a system capable of a high degree of single-mode selectivity, which is sensitive to changes in driving current. Multi-moded QCLs operating around 2.9 THz are thus modified to achieve purely electronic discrete tuning spanning over 160 GHz with an average tuning resolution of 30 GHz. Applying the same multi-resonance filter to QCLs with gain peaks around 2.65 and 2.9 THz leads to dual-mode lasing with an electrically controlled frequency separation of between 190 and 267 GHz. A phase sensitive mode selection mechanism is experimentally confirmed by the observation of divergent fine-tuning of the lasing modes.