Open AccessWatt-level, high wall plug efficiency, continuous-wave room temperature quantum cascade laser emitting at 7.7µm
Author(s) -
Huan Wang,
Jinchuan Zhang,
Cheng Feng,
Ning Zhuo,
Shenqiang Zhai,
Junqi Liu,
Lijun Wang,
Shuman Liu,
Fengqi Liu,
Zhanguo Wang
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.412943
Subject(s) - cascade , materials science , optics , laser , continuous wave , heat sink , quantum cascade laser , optoelectronics , dissipation , physics , chemistry , chromatography , thermodynamics
In this article, a InP based strain-balanced In 0.58 Ga 0.42 As/In 0.47 Al 0.53 As quantum cascade laser emitting at 7.7µm is reported. The active region is based on a slightly-diagonal bound to continuum design with 50 cascade stages and a low voltage defect Δ inj of 96 meV. By optimizing the active region and waveguide structure, the waveguide loss α w of 1.18cm -1 are obtained, which contribute to a high wall-plug efficiency (WPE) of 9.08% and low threshold current of only 1.09 kA/cm 2 in continuous-wave(CW) operation at 293K. The maximum single facet output power of 1.17W in CW operation and 2.3W in pulsed operation are measured at 293K. The narrow ridge and buried ridge structure epi-side-down-mounted on the diamond heatsink improved the heat dissipation of the device. A beam of pure zero order mode and a broad external-cavity tuning range from 7.16µm to 8.16µm are also achieved.