High-Efficiency Midinfrared LEDs with High Brightness for High-Fidelity Infrared Scene Projection

State-of-the-art Infrared Scene Projection Systems (IRSP) are using Light Emitting Diode (LED) arrays to generate virtual reality scenes emulating real operating environments for a variety of military and industrial detection systems, including infrared missile seekers, search and track systems, and thermal imagers. LEDs made with Type II InAs/GaSb strained super lattice heterostructures have demonstrated excellent performance in the mid-wave infrared. However the light extraction efficiency of devices is still limited to a few percent due to total internal reflection at the high-index substrate-air interface. This proposal seeks to leverage the field-enhancement characteristics of plasmonic metasurfaces to improve the out coupling efficiency of IR LEDs. Our approach will investigate LED active regions embedded between a metal ground plane and sub-wavelength grating structures that efficiently funnel out photons otherwise trapped as bound modes within the cavity.