Anomalous Mode Transitions in High Power Distributed Bragg Reflector Quantum Cascade Lasers

Feng-Min Cheng; Jin-Chuan Zhang; Zeng-Hui Gu; Dong-Bo Wang; Ning Zhuo; Shen-Qiang Zhai; Li-Jun Wang; Jun-Qi Liu; Shu-Man Liu; Feng-Qi Liu; Zhan-Guo Wang

doi:10.1186/s11671-019-3151-3

Anomalous Mode Transitions in High Power Distributed Bragg Reflector Quantum Cascade Lasers

Nanoscale Res Lett. 2019 Oct 22;14(1):331. doi: 10.1186/s11671-019-3151-3.

Authors

Feng-Min Cheng^{1

2}, Jin-Chuan Zhang³, Zeng-Hui Gu^{1

2}, Dong-Bo Wang^{1

2}, Ning Zhuo¹, Shen-Qiang Zhai⁴, Li-Jun Wang^{1

2}, Jun-Qi Liu^{1

2}, Shu-Man Liu^{1

2}, Feng-Qi Liu^{1

2

5}, Zhan-Guo Wang^{1

2}

Affiliations

¹ Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices, P.O. Box 912, Beijing, 100083, China.
² Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China.
³ Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices, P.O. Box 912, Beijing, 100083, China. zhangjinchuan@semi.ac.cn.
⁴ Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices, P.O. Box 912, Beijing, 100083, China. zsqlzsmbj@semi.ac.cn.
⁵ Beijing Academy of Quantum Information Sciences, Beijing, 100193, China.

Abstract

In this paper, an anomalous spectral data of distributed Bragg reflector (DBR) quantum cascade lasers (QCLs) emitting around 7.6 μm is presented. The two-section DBR lasers, consisting of a gain section and an unpumped Bragg reflector, display an output power above 0.6 W in continuous wave (CW) mode at room temperature. The anomalous spectral data is defined as a longitudinal mode which moves toward shorter wavelengths with increasing temperature or injection current, which is unexpected. Although the longer wavelength modes are expected to start lasing when raising device temperature or injection current, occasional mode hops to a shorter wavelength are seen. These anomalous mode transitions are explained by means of modal analysis. The thermal-induced change of the refractive index implied by an increase in the temperature or injection current yields nearly periodic transitions between cavity modes.

Keywords: Anomalous mode transitions; Distributed Bragg reflector; Quantum cascade laser.

Abstract

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