Comparison of birefringent electric split-ring resonator and meanderline structures as quarter-wave plates at terahertz frequencies.
We have fabricated a quarter-wave plate from a single layer of birefringent electric split-ring resonators (ELC). For comparison, an appropriately scaled double layer meanderline structure was fabricated. At the design frequency of 639 GHz, the ELC structure achieves 99.9% circular polarization while the meanderline achieves 99.6%. The me-anderline displays a larger bandwidth of operation, attaining over 99% circular polarization from 615 - 743 GHz, while the ELC achieves 99% from 626 - 660 GHz. However, both are broad enough for use with CW sources making ELCs a more attractive choice due to the ease of fabrication. Both samples are free standing with a total thickness of 70 microm for the meanderline structure and a mere 20 microm for the ELC highlighting the large degree of birefringence exhibited with metamaterial structures.
Strikwerda
Andrew C
AC
Department of Physics, Boston University, Boston, Massachusetts 02215, USA.
Fan
Kebin
K
Tao
Hu
H
Pilon
Daniel V
DV
Zhang
Xin
X
Averitt
Richard D
RD
D000162:Acoustics; D001718:Birefringence; D003460:Crystallization; D004560:Electricity; D004574:Electromagnetic Fields; D004578:Electron Spin Resonance Spectroscopy; D004867:Equipment Design; D008422:Materials Testing / Q000295:instrumentation / Q000379:methods*; D008853:Microscopy; D011827:Radiation; D012666:Semiconductors; D013055:Spectrophotometry, Infrared