Optical nanoantennas as on-chip spectrometer: Discriminating the wavelength of infrared light

Abstract

Based on the size-dependent resonant property of optical nanoantennas, we propose and theoretically verify that the optical detector element, which is composed of three different-size dipole nanoantennas (these antennas arrayed in the same plane look like a Yagi-Uda antenna), can discriminate the wavelength of the detected infrared light. As it behaves like a spectrometer that just needs to be laid on a micro-chip, we can refer to it as on-chip spectrometer. Such optical detector element also can be well extended to the visible-light region, and especially it can capture colour information by itself without Bayer filter.