Temperature dependence of narrow-band terahertz generation from periodically poled lithium niobate

Abstract

Femtosecond optical pulses are used to generate narrow-band terahertz wave forms via optical rectification in a periodically poled lithium niobate crystal. By cooling the crystal to reduce losses due to phonon absorption, we are able to obtain bandwidths as narrow as 18 GHz at a carrier frequency of 1.8 THz. Temperature-dependent measurements show insignificant bandwidth broadening between 10 and 120 K, although the terahertz power substantially decreases as the temperature increases. Absolute power measurements indicate a conversion efficiency of at least 10−5.