Over Three Hundred Percent Increased Light Extraction from Emitters at Mid-Infrared Wavelengths Using Metalenses

Low extraction efficiencies continue to be a source of parasitic heating and decreased performance in infrared light-emitting diodes. Research into metasurfaces and the advance of methods used to fabricate these planar structures have made it possible to realize a metalens tailored to increasing the radial output of geometrically constrained superlattice light-emitting diodes (SLEDs). The metalens presented here, which allows for unprecedented control over optical wavefronts on a subwavelength scale, was designed to promote the extraction for an emitter of a specific mid-wave infrared (MWIR) wavelength, dielectric material, and unpolarized, Lambertian output. Results from a representative optical sample showed an enhanced output of 3.3× of the metalens design when compared to a planar surface. We also include results of a design of experiment where metalens performance was tracked as a function of distance from the emitter and the height of nanopillars making up the metalens.