title: Three-dimensional inverted photonic grating with engineerable refractive indices for broadband antireflection of terahertz waves.
abstract: Reduction of reflection is of great importance in optical spectroscopy to reduce interference and increase throughput. Here we demonstrate a three-dimensional inverted photonic grating device design using only one material-silicon. Enhanced transmission compared to planar silicon wafers is observed from 0.2 THz to over 7.3 THz for a device with a 15 µm period, which covers most of the terahertz band, and its relative 3 dB bandwidth (δf/f(c)) is a noteworthy 116.3%. Moreover, the device is polarization independent and can perform up to a large incident angle.
authors.affiliation: Center for Terahertz Research, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.
authors.forename: Yuting W
authors.initials: YW
authors.lastname: Chen
authors.forename: Pengyu
authors.initials: P
authors.lastname: Han
authors.forename: X-C
authors.initials: XC
authors.lastname: Zhang
authors.forename: Mei-Ling
authors.initials: ML
authors.lastname: Kuo
authors.forename: Shawn-Yu
authors.initials: SY
authors.lastname: Lin