Open AccessThin terahertz-wave phase shifter by flexible film metamaterial with high transmission
Author(s) -
Zhonghua Han,
Seigo Ohno,
Yu Tao,
Kouji Nawata,
T. Notake,
Yuma Takida,
Hiroaki Minamide
Publication year - 2017
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.25.031186
Subject(s) - metamaterial , terahertz radiation , optics , phase shift module , materials science , optoelectronics , split ring resonator , polarization (electrochemistry) , insertion loss , physics , chemistry
Thin terahertz (THz)-wave optical components are fundamentally important for integrated THz-wave spectroscopy and imaging systems, especially for phase manipulation devices. As described herein, a thin THz-wave phase shifter was developed using a flexible film metamaterial with high transmission and polarization independent properties. The metamaterial unit structure employs double-layer un-split ring resonators (USRRs) with a designed distance between the two layers to obtain phase retardance of π/2, thus constituting a THz-wave phase shifter. The metamaterial design keeps the transmission coefficient as high as 0.91. The phase shifter also has polarization independence due to the four-fold symmetry of the USRR structure. Because of the subwavelength feature size of the USRR, this shifter can offer benefits for manipulating the spatial profile for the THz-wave phase through design of a binary optics phase plate by arranging a USRR array. The thickness of 48 μm has benefits for developing integrated THz optics and other applications that demand compactness and flexibility. The developed film size of 5 cm × 5 cm from the device fabrication process is suitable for THz lenses or gratings of large optical components.