A quasi-optic dielectric terahertz cavity

Summary form only given. We report the first demonstration of a quasi-optic broadband THz dielectric cavity coupled efficiently through optical tunneling. The cavity system consists of a pair of high-resistivity silicon cylindrical optics. An air-slab with a thickness of d = 18 /spl mu/m between the plane surfaces of these two optics is the tunneling coupler for the THz beam incident onto the boundary at an angle beyond critical angle. When placed in a beam of subpsec THz pulses, the output of the cavity consists of a train of psec THz pulses with a 228 psec separation between pulses and a 1/e amplitude decay time of 0.65 nsec.