Narrow-band THz waveforms from optical rectification of femtosecond optical pulses in periodically poled lithium niobate

Coherent sources of THz radiation are of great interest for a wide range of applications in condensed matter and molecular spectroscopy and sensing, imaging, and high-speed electronics. Broad-band coherent sigle-cycle THz pulses are readily generated using optical rectification of femtosecond pulse, but narrow-band sources remain a significant technological challenge.