Flat mid-infrared composite plasmonic materials using lateral doping-patterned semiconductors

We demonstrate lateral control of carrier concentration in doped Si for mid-infrared plasmonic applications. Using commercially available spin-dopants, we show that doped silicon can act as a plasmonic material at mid-infrared wavelengths, and that control of the doping pattern allows for the development of flat, single-material plasmonic composites. Our materials are characterized by infrared spectroscopy and microscopy, surface profilometry and infrared emissivity measurements. We demonstrate the ability to fabricate subwavelength doped features and show distinct diffraction from one-dimensional arrays of 'metal' lines patterned in our material system.