Surface-emitted terahertz-wave from PPLN optical waveguide

We report surface-emitted terahertz (THz)-wave generation from PPLN optical waveguide using difference frequency mixing. The waveguide was fabricated by machining process instead of conventional proton-exchange. The confinement of only optical pulses makes it possible to achieve higher conversion efficiency and minimize the absorption loss of THz-wave in PPLN crystal.