Whispering-gallery-mode terahertz pulse propagation on a curved metallic plate
Abstract
We demonstrate terahertz (THz) pulse propagation on a cylindrical aluminum plate, with low loss and negligible dispersion via transverse-electric type whispering gallery (WG) modes. We observe an apparent superluminal effect where the group velocity is greater than c, and explain this phenomenon by means of a plane-wave description of the WG modes. The propagation loss is dominated by the diffraction loss due to unbounded lateral spreading, with a negligible ohmic-loss contribution. Both experimental and theoretical results indicate a total loss as low as 2.6 dB/m at a frequency of 0.47 THz.
- Publication:
-
Applied Physics Letters
- Pub Date:
- July 2010
- DOI:
- Bibcode:
- 2010ApPhL..97c1106M
- Keywords:
-
- aluminium;
- losses;
- microwave photonics;
- optical waveguides;
- plates (structures);
- terahertz wave generation;
- whispering gallery modes;
- 42.79.Gn;
- 84.40.-x;
- Optical waveguides and couplers;
- Radiowave and microwave technology