Mid-infrared spectral region (2-4 μm) is gaining significant attention recently due to the presence of
numerous enabling applications in the field of gas sensing, medical, and defense applications. Gas sensing in this spectral
region is attractive due to the presence of numerous absorption lines for such gases as methane, ethane, ozone, carbon
dioxide, carbon monoxide, etc. Sensing of the mentioned gas species is of particular importance for applications such as
atmospheric LIDAR, petrochemical industry, greenhouse gas monitoring, etc. Defense applications benefit from the
presence of covert atmospheric transmission window in the 2.1-2.3 micron band which is more eye-safe and offers less
Rayleigh scattering than the conventional atmospheric windows in the near-infrared. Major requirement to enable these
application is the availability of high-performance, continuous-wave laser sources in this window. Type-I GaSb-based
laser diodes are ideal candidates for these applications as they offer direct emission possibility, high-gain and continuous
wave operation. Moreover, due to the nature of type-I transition, these devices have a characteristic low operation
voltage, which results in very low input powers and high wall-plug efficiency.
In this work, we present recent results of 2 μm – 3.0 μm wavelength room-temperature CW light sources based
on type-I GaSb developed at Brolis Semiconductors. We discuss performance of defense oriented high-power multimode
laser diodes with < 1 W CW power output with over 30 % WPE as well as ~ 100 mW single TE00 Fabry-Perot chips. In
addition, recent development efforts on sensing oriented broad gain superluminescent gain chips will be presented.