Terahertz electro-optic wavelength conversion in GaAs quantum wells: Improved efficiency and room-temperature operation

A 4-mum-thick sample containing 50 GaAs/AlGaAs asymmetric coupled quantum wells was driven with a strong terahertz (THz) electric field of frequency omega(THz) and probed with a near-infrared (NIR) laser of frequency omega(NIR). The THz beam modulated the probe to generate sidebands at omega(NIR)+nomega(THz), where n is an integer. Up to 0.2% of the NIR laser power was converted into the n=+1 sideband at 20 K, and sidebands were observed up to room temperature. The strong THz fields also induced changes in the NIR absorption of the sample. (C) 2004 American Institute of Physics.