Broadband Terahertz Quantum Cascade Laser Dual‐Comb Sources under Off‐Resonant Microwave Injection
Broadband Terahertz Quantum Cascade Laser Dual‐Comb Sources under Off‐Resonant Microwave Injection
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关闭谐振微波注入下的宽带太赫兹量子级联激光器双梳状源
DOI：
10.1002/adpr.202100361
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发表时间：
2021-11
期刊：
影响因子：
--
通讯作者：
Hua Li
中科院分区：
文献类型：
--
作者：
Liao Xiaoyu;Ziping Li;Zhou Kang;Guan Wen;Zhao Yiran;Wang Chenjie;Wenjian Wan;Yang Sijia;Zhang Zhenzhen;Wang Chang;J C Cao;Zeng Heping;Hua Li
宽带双梳光谱技术以其光谱分辨率高、检测速度快等独特优势吸引了人们越来越多的兴趣。虽然双梳技术在红外波段已经相对成熟，但由于缺乏高性能的宽带太赫兹双梳光源，目前还不能在太赫兹波段进行商业应用。在太赫兹频率范围内，电泵浦量子级联激光器(QCL)是一种适合于双梳运转的候选激光器。然而，自由运行的太赫兹QCL双梳光源通常显示有限的光带宽($sim$100-200 GHz)。尽管谐振微波注入锁定已被广泛应用于通过调制腔往返频率的激光驱动电流来展宽太赫兹准分子激光器的发射光谱，但由于谐振注入和非理想微波电路所产生的大的相位噪声，它很难用于展宽双梳带宽。因此，获得能够充分利用激光增益带宽的宽带太赫兹双梳光源是一项具有挑战性的工作。在这里，我们使用非共振微波注入来显著展宽发射约4.2THz的太赫兹QCL双梳光源的双梳带宽。测量的光纤双梳带宽从自由运转的147 GHz展宽到非共振注入下的450 GHz。通过对滤光片和砷化镓标准具的透过率测量，实验证明了双梳带宽的展宽。通过一个基于速率方程模型的简单数值分析，我们解释了非共振微波注入下的宽带双梳运转是由于较宽的激光带宽和较高的相位匹配度所致。
Broadband dual-comb spectroscopy has attracted increasing interests due to its unique advantages in high spectral resolution, fast detection, and so on. Although the dual-comb technique is relatively mature in the infrared wavelengths, it is, currently, not commercially capable of practical applications in the terahertz regime due to the lack of high performance broadband terahertz dual-comb sources. In the terahertz frequency range, the electrically pumped quantum cascade laser (QCL) is a suitable candidate for the dual-comb operation. However, free running terahertz QCL dual-comb sources normally show limited optical bandwidths ($sim$100-200 GHz). Although the resonant microwave injection locking has been widely used to broaden the emission spectra of terahertz QCLs by modulating the laser drive current at the cavity round-trip frequency, it is hard to be employed to broaden the dual-comb bandwidths due to the large phase noise induced by the resonant injection and non-ideal microwave circuits. Therefore, it is challenging to obtain broadband terahertz dual-comb sources that can fully exploits the laser gain bandwidth. Here, we employ an off-resonant microwave injection to significantly broaden the dual-comb bandwidth of a terahertz QCL dual-comb source emitting around 4.2 THz. The measured optical dual-comb bandwidth is broadened from 147 GHz in free running to $>$450 GHz under the off-resonant injection. The broadened dual-comb bandwidth is experimentally proved by the transmission measurements of a filter and a GaAs etalon. By performing a simple numerical analysis based on a rate equation model, we explain that the broadband dual-comb operation under the off-resonant microwave injection could be resulted from a wider lasing bandwidth and a higher degree of phase matching.
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影响因子：
4
作者：
Brandstetter, Martin;Deutsch, Christoph;Unterrainer, Karl
通讯作者：
Unterrainer, Karl
影响因子：
35
作者：
Barbieri, Stefano;Ravaro, Marco;Davies, A. Giles
通讯作者：
Davies, A. Giles
DOI：
10.1002/9781118771075
发表时间：
2018-07
期刊：
--
影响因子：
--
作者：
R. Rossi
通讯作者：
R. Rossi
影响因子：
11
作者：
É. Rodriguez;A. Mottaghizadeh;D. Gacemi;M. Jeannin;Z. Asghari;A. Vasanelli;Y. Todorov;Qi Jie Wang;C. Sirtori
通讯作者：
É. Rodriguez;A. Mottaghizadeh;D. Gacemi;M. Jeannin;Z. Asghari;A. Vasanelli;Y. Todorov;Qi Jie Wang;C. Sirtori
影响因子：
4
作者：
Rosch, Markus;Scalari, Giacomo;Faist, Jerome
通讯作者：
Faist, Jerome