Detection of freely propagating terahertz radiation by use of optical second-harmonic generation

Ajay Nahata, Tony F. Heinz
1998 Optics Letters  
We report the application of electric-field-induced optical second-harmonic generation as a new technique for measuring the field of freely propagating terahertz radiation. Using silicon as the nonlinear medium, we demonstrate subpicosecond time resolution and a sampling signal that varies linearly with the terahertz electric field. This approach, which is attractive for centrosymmetric media, permits a significantly broadened class of materials to be exploited for free-space sampling measurements.
doi:10.1364/ol.23.000067 pmid:18084414 fatcat:6fyi6zyu6vafhfxh6leoixyxk4