Open AccessRoom temperature quantum cascade lasers with 22% wall plug efficiency in continuous-wave operation
Author(s) -
F. Wang,
S. Slivken,
Donghai Wu,
Manijeh Razeghi
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.394916
Subject(s) - materials science , cascade , continuous wave , optics , laser , optoelectronics , quantum cascade laser , fabrication , wavelength , physics , medicine , chemistry , alternative medicine , chromatography , pathology
We report the demonstration of quantum cascade lasers (QCLs) with improved efficiency emitting at a wavelength of 4.9 µm in pulsed and continuous-wave (CW) operation. Based on an established design and guided by simulation, the number of QCL-emitting stages is increased in order to realize a 29.3% wall plug efficiency (WPE) in pulsed operation at room temperature. With proper fabrication and packaging, a 5-mm-long, 8-µm-wide QCL with a buried ridge waveguide is capable of 22% CW WPE and 5.6 W CW output power at room temperature. This corresponds to an extremely high optical density at the output facet of ∼35 MW/cm 2 , without any damage.