Wavelength-Stable Metal Grating Distributed Feedback Quantum Cascade Laser Emitting at λ ~ 7.2 μm
Kedi Ma,
Zizhuo Liu,
Fengmin Cheng,
Pengchang Yang,
Hongxiao Li,
Shan Niu,
Gaohui Ge,
Hao Xu,
Ning Zhuo,
Hui Su,
Jinchuan Zhang
Affiliations
Kedi Ma
Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
Zizhuo Liu
Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
Fengmin Cheng
Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
Pengchang Yang
Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
Hongxiao Li
Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
Shan Niu
Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
Gaohui Ge
School of Physics, University of Electronic Science and Technology of China, Chengdu 611731, China
Hao Xu
School of Physics, University of Electronic Science and Technology of China, Chengdu 611731, China
Ning Zhuo
Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
Hui Su
Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
Jinchuan Zhang
Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
In this research, we demonstrate a wavelength-stable continuous wave (CW) distributed feedback (DFB) quantum cascade laser (QCL) emitting at 7.2 μm using a surface metal grating approach without epitaxial regrowth. The deep metal grating provides an appropriate DFB coupling coefficient and enhanced thermal extraction, resulting in improved lasing performance and the realization of impressive wavelength stability. Quantitatively, the temperature tuning coefficient of the single-mode emission is only 0.54 nm/°C from 20 °C to 70 °C, and the current tuning coefficient of the single-mode emission is 3.2 nm/A from 1.0 A to 1.6 A. A DFB-QCL with a 2 mm cavity length exhibits a low threshold current of 0.6 A and a power of 1.1 W with a slope efficiency of 1 W/A in the CW mode at 300 K. A single-mode operation with a side mode suppression ratio of 33 dB and a single-lobed far-field without beam steering is obtained in the working temperature range of 20–70 °C The improved wavelength stability using a deep surface metal grating approach promises simplified fabrication, which is meaningful for the commercial applications of QCLs.
