Dual-wavelength switchable, mid-infrared quantum cascade laser with two shallow-etched distributed Bragg reflectors

YA dual-wavelength quantum cascade laser (QCL) with two shallow-etched distributed Bragg reflectors is designed and fabricated. Based on a heterogeneous active region within a single waveguide, single-mode emission at 7.6 mu m and 8.2 mu m was achieved. The two wavelengths can be independently controlled by selective current injection on different regions of the device, which are electrically isolated. High optical powers of about 275mW and 218mW at room temperature were obtained for the single-mode emission at 7.6 mu m and 8.2 mu m, respectively. The presented design concept for high power, dual-wavelength switchable, mid-infrared QCLs is significant in developing miniaturized multi-species gas detection systems. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement