Plasmonic absorption nanoantenna for frequency selective mid-infrared detection

Optical antennas hold great promise for increasing the efficiency of photovoltaics, light-emitting devices, and optical sensors1. This paper discusses one strategy to achieve frequency selective detection at mid-infrared region, which utilize the plasmonic absorption nanoantenna. The infrared devices realized by such nanoantenna array have merits such as more flexibility of frequency selectivity, and its highlights of polarization properties, which will develop increased functionality for next generation focal plane arrays2. We investigated one example of such nanoantenna devices to tune its plasmonic resonance for achieving frequency selectivity and polarization properties. We also demonstrated its multiplex band absorption, and one tactics to broaden its absorption spectrum. The broad infrared sensitivity of nanoantenna devices would enable multiplex bands infrared imaging detectors. The optical properties of such examples are simulated and measurement which shows perfect absorption in certainty frequency-band. By exploiting nanoantenna as light-harvesting and carrier generation element, plasmonic absorption nanoantenna devices would realize both polarization- and wavelength-selective detection, which would overcome the band gap limitations of existing semiconducting materials.