Fabrication of Single-Mode, Distributed-Feedback, Interband Cascade Lasers

Type-II interband cascade lasers (ICLs) based on the GaSb material system represent an enabling technology for laser absorption spectroscopy in the 3-to-5-μm wavelength range. Instruments operating in this spectral regime can precisely match strong absorption lines of several gas molecules of interest in atmospheric science and environmental monitoring, specifically methane, ethane, other alkanes, and inorganic gases. Compared with non-semiconductor-based laser technologies, ICLs can be made more compact and power efficient, ultimately leading to more portable, robust, and manufacturable spectroscopy instruments.