High-performance mid-infrared GaSb laser diodes for defence and sensing applications

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, environmental and defense applications. Major requirement for these applications is the availability of laser sources in the atmospheric transmission window free of water vapor absorption, such as the 2-2.3 μm spectral window. Type-I GaSb-based laser diodes are ideal candidates for these applications being compact, electrically pumped, power efficient and able to operate at room temperature in continuous-wave. Moreover, due to the nature of type-I transition these devices have characteristic low operation voltage, typically below 1 V, resulting in low power consumption, and high-temperature of operation. In this work, we present recent progress of 2.1 μm wavelength single-spatial mode GaSb type-I laser diode development at Brolis Semiconductors. Experimental device structures were grown by solid-source multi-wafer MBE, consisting of an active region with 2 compressively strained (~1.3 %) GaInAsSb quantum wells. Epi-wafers were processed into a ridge-waveguide devices and mounted on Cu or CuW heatsink. Presented devices feature state-of-the art performance in CW mode with < 1.2 W and 30 % WPE for single emitter device as well as 9 W and 28 % WPE for a laser diode bar.