Enhancement of THz EO sampling efficiency using waveguides

We have observed a significant enhancement in the electro-optic sampling efficiency for THz radiation by using focusing effect in a metallic tapered parallel plate waveguide and also an optical waveguide in LiNbO3 employed as an EO crystal. The total enhancement factor exceeds an order of magnitude as compared to the case with a bulk LiNbO3 crystal coupled with a Si prism.