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 $0.2\mathrm{THz}$ to over $7.3\mathrm{THz}$ for a device with a $15\mathrm{\mu m}$ period, which covers most of the terahertz band, and its relative $3\mathrm{dB}$ bandwidth $(\delta f/f_c)$ is a noteworthy 116.3%. Moreover, the device is polarization independent and can perform up to a large incident angle.

© 2010 Optical Society of America

Grating-assisted coupling of terahertz waves into a dielectric waveguide studied by terahertz time-domain spectroscopy

Jean-François Roux, Fabien Aquistapace, Frédéric Garet, Lionel Duvillaret, and Jean-Louis Coutaz
Appl. Opt. 41(30) 6507-6513 (2002)

Broadband antireflection coating for optimized terahertz beam splitters

Weien Lai, Norman Born, Lorenz Maximilian Schneider, Arash Rahimi-Iman, Jan C. Balzer, and Martin Koch
Opt. Mater. Express 5(12) 2812-2819 (2015)

Materials with on-demand refractive indices in the terahertz range

Christelle Kadlec, Filip Kadlec, Petr Kužel, Karine Blary, and Patrick Mounaix
Opt. Lett. 33(19) 2275-2277 (2008)

Bilayer metallic nanofilms as broadband antireflection coatings in terahertz optical systems

Wei En Lai, Huai Wu Zhang, Yao Hua Zhu, Qi Ye Wen, Wei Wei Du, and Xiao Li Tang
Opt. Express 22(3) 2174-2184 (2014)

Observation of the waveguide resonance in a periodically patterned high refractive index broadband antireflection coating

O. Stenzel, S. Wilbrandt, X. Chen, R. Schlegel, L. Coriand, A. Duparré, U. Zeitner, T. Benkenstein, and C. Wächter
Appl. Opt. 53(14) 3147-3156 (2014)