Three-dimensional inverted photonic grating with engineerable refractive indices for broadband antireflection of terahertz waves.
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.
Chen
Yuting W
YW
Center for Terahertz Research, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.
Han
Pengyu
P
Zhang
X-C
XC
Kuo
Mei-Ling
ML
Lin
Shawn-Yu
SY