Generation of narrow-band terahertz radiation via optical rectification of femtosecond pulses in periodically poled lithium niobate

We demonstrate a promising technique for generating narrow-band terahertz electromagnetic radiation. Femtosecond optical pulses are propagated through a periodically poled lithium-niobate crystal, where the domain length is matched to the walk-off length between the optical and THz pulses. The bandwidth of the THz wave forms is 0.11 at 1.7 THz. Optical rectification gives rise to a THz wave form which corresponds to the domain structure of the periodically poled lithium niobate. (C) 2000 American Institute of Physics. [S0003-6951(00)03818-3].