Terahertz nonlinear waveguide-antenna driven by a femtosecond laser

An active waveguide-antenna in which the nonlinear crystal is the source of THz radiation is considered. The coherent terahertz radiation generated via optical rectification of 100 fs pulses of a Ti: sapphire laser in a system of a “nonlinear optical crystal partially filling the cross section of a metal rectangular waveguide” is investigated. It is shown that the fulfillment of the phase-matching condition and the optimization of the characteristics of radiation transmission through the integrated system “nonlinear crystal + waveguide” affect the efficiency of generation of THz radiation.