Frequency tuning behaviour of terahertz quantum cascade lasers revealed by a laser beating scheme
Artikel i vetenskaplig tidskrift, 2021

In the terahertz frequency range, the commercialized spectrometers, such as the Fourier transform infrared and time domain spectroscopies, show spectral resolutions between a hundred megahertz and a few gigahertz. Therefore, the high precision frequency tuning ability of terahertz lasers cannot be revealed by these traditional spectroscopic techniques. In this work, we demonstrate a laser beating experiment to investigate the frequency tuning characteristics of terahertz quantum cascade lasers (QCLs) induced by temperature or drive current. Two terahertz QCLs emitting around 4.2 THz with identical active regions and laser dimensions (150 μm wide and 6 mm long) are employed in the beating experiment. One laser is operated as a frequency comb and the other one is driven at a lower current to emit a single frequency. To measure the beating signal, the single mode laser is used as a fast detector (laser self-detection). The laser beating scheme allows the high precision measurement of the frequency tuning of the single mode terahertz QCL. The experimental results show that in the investigated temperature and current ranges, the frequency tuning coefficients of the terahertz QCL are 6.1 MHz/0.1 K (temperature tuning) and 2.7 MHz/mA (current tuning) that cannot be revealed by a traditional terahertz spectrometer. The laser beating technique shows potential abilities in high precision linewidth measurements of narrow absorption lines and multi-channel terahertz communications.

Författare

WEN GUAN

Chinese Academy of Sciences

ShanghaiTech University

XIAOYU LIAO

Chinese Academy of Sciences

ZIPING LI

Chinese Academy of Sciences

WENJIAN WAN

Chinese Academy of Sciences

KANG ZHOU

Chinese Academy of Sciences

YIRAN ZHAO

Chinese Academy of Sciences

CHENJIE WANG

Chinese Academy of Sciences

XUHONG MA

Chinese Academy of Sciences

Shu Min Wang

Chalmers, Mikroteknologi och nanovetenskap (MC2), Fotonik

Chinese Academy of Sciences

J. C. CAO

Chinese Academy of Sciences

DONG XU

SIMIC Advanced Micro Semiconductors Co., Ltd.

Chinese Academy of Sciences

JUNWEN ZHANG

Fudan University

NAN CHI

Fudan University

HUA LI

Chinese Academy of Sciences

Optics Express

1094-4087 (ISSN)

Vol. 29 14 21269-21279

Ämneskategorier

Atom- och molekylfysik och optik

Annan fysik

Annan elektroteknik och elektronik

DOI

10.1364/OE.427326

PubMed

34265917

Mer information

Senast uppdaterat

2021-07-01