A laser supercontinuum is generated by cross-phase modulation (XPM) driven by an intense terahertz (THz) field in organic crystal OHQ-N2S. In this highly nonlinear medium, the THz electric field induces a time-varying optical phase modulation, which causes a spectacular spectral broadening and shifting of a co-propagating near-infrared laser pulse. The effect is enabled by the large electro-optic coefficient, the low absorption, and the good velocity matching between the laser and the THz pulse over the OHQ-N2S crystal thickness. The XPM occurs when the THz field is aligned along the polar axis of the OHQ-N2S. The results display a promising pathway for ultrafast control of the spectral and temporal properties of laser pulses using THz stimuli.
Funding. Swiss National Science Foundation (SNSF), Schweizerischer Nationalfonds zur F\\u00F6rderung der Wissenschaftlichen Forschung (IZKSZ2_162129, IZLRZ2_ 164051); National Research Foundation of Korea (2014R1A5A1009799, 2015K1A3A1A14004646); European Commission (CNECTICT604391).