Mid-Wave Infrared (MWIR) Quantum Cascade Laser (QCL) Combiner

Mid-wave Infrared (MWIR) is a high-utility bandwidth of the electromagnetic (EM) spectrum for performing imaging, sensing, and other forms of EM transmission/ detection through the Earth’s atmosphere.  In comparison to the shorter wavelengths of the near-infrared (NIR) and short-wave infrared (SWIR), reflected solar radiance is significantly reduced in the mid-wave. In comparison to longer wavelengths, thermal emissive radiance from normal atmospheric and surface conditions is also at a minimum. MWIR transmission through the atmosphere is primarily limited by absorption from atmospheric gases and water vapor, with two bandwidth regions exhibiting the least losses from gaseous absorption, defining the “atmospheric windows” for MWIR of approximately 3.5 - 4.05 and 4.6 – 5.0 mm. MWIR laser systems operating in these ranges have multiple applications in U.S. Armed Forces systems and stratagems, including, but not limited to: Target Illumination and Designation, Surveillance and Reconnaissance, Sensing and Identification, Infrared Countermeasures, and Communications.