Title :
Low-Loss Terahertz Artificial Dielectric Birefringent Quarter-Wave Plates
Author :
Saha, Shimul Chandra ; Ma, Yong ; Grant, James P. ; Khalid, Ata ; Cumming, David R S
Author_Institution :
Dept. of Electron. & Electr. Eng., Univ. of Glasgow, Glasgow, UK
Abstract :
We have developed anisotropically etched low-loss artificial dielectric birefringent quarter-wave plates (QWPs) for use at 1.5 and 2.8 THz. The grating period for both QWPs is 20 ??m. We etched 46- and 30- ??m-deep gratings to obtain a ??/2 phase retardance between transverse-magnetic and transverse-electric polarization propagating through the QWPs at 1.5 and 2.8 THz, respectively. A SU8 antireflection coating is used to further improve the transmission coefficient by up to 21%. The measured results from Fourier transform infrared spectroscopy show a good agreement with designed specifications.
Keywords :
Fourier transform spectroscopy; antireflection coatings; birefringence; diffraction gratings; etching; infrared spectroscopy; light polarisation; microwave photonics; optical fabrication; optical losses; optical retarders; terahertz wave devices; Fourier transform infrared spectroscopy; SU8 antireflection coating; anisotropic etching; deep gratings; frequency 1.5 THz; frequency 2.8 THz; grating period; low-loss artificial dielectric birefringent quarter-wave plates; phase retardance; terahertz quarter-wave plates; transverse-electric polarization; transverse-magnetic polarization; Birefringence; dielectric polarization; gratings; submillimeter-wave devices;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2009.2036242
