Flare coupled metal parallel-plate waveguides for high resolution terahertz time-domain spectroscopy

Michael Theuer, S. Sree Harsha, D. Grischkowsky
2010 Journal of Applied Physics  
We report on a new coupling scheme for high resolution terahertz spectroscopy of microcrystalline films using parallel-plate waveguides. Metal flares are used to couple the terahertz radiation into and out of the waveguide. Very good coupling ratios as high as 35% at 1 THz from a collimated free-space beam into a subwavelength gap are obtained. This microwave approach is compared in terms of coupling ratio and spectral characteristics to the established technique of quasioptic coupling to
more » ... c coupling to parallel-plate waveguides using silicon lenses. Various samples at room and cryogenic temperatures are measured to show the capabilities of flare coupling for high resolution terahertz spectroscopy.
doi:10.1063/1.3516307 fatcat:qtryzic5yzektayw2jedadgooa