High-performance InP-based midinfrared quantum cascade lasers at Northwestern University

We present recent performance highlights of midinfrared quantum cascade lasers (QCLs) based on an InP material system. At a representative wavelength around 4.7 mu m, a number of breakthroughs have been achieved with concentrated effort. These breakthroughs include watt-level continuous wave operation at room temperature, greater than 50% peak wall plug efficiency at low temperatures, 100-W-level pulsed mode operation at room temperature, and 10-W-level pulsed mode operation of photonic crystal distributed feedback quantum cascade lasers at room temperature. Since the QCL technology is wavelength adaptive in nature, these demonstrations promise significant room for improvement across a wide range of mid-IR wavelengths. (C) 2010 Society of Photo-Optical Instrumentation Engineers. [DOI: 10.1117/1.3497623]