Polarization analysis of terahertz radiation generated by four-wave mixing in air

Aurélien Houard (1) , Yi Liu (1) , Bernard Prade (1) , André Mysyrowicz (1)

1 LOA - Laboratoire d'optique appliquée

We examine the generation of terahertz by optical rectification of fundamental infrared beam with its first harmonic in ionized air. From polarization measurements we identify an important, yet so far unreported cross term (X(3)xyxy + X(3)xyyx) of the nonlinear susceptibility tensor. Omission of this term leads to an error by a factor 10^6 of the THz intensity obtained with certain polarization configurations.

Keywords: terahertz; non-linear optics; plasma

Domains: Physics [physics]; Physics [physics]; Optics [physics.optics]

Aurélien Houard, Yi Liu, Bernard Prade, André Mysyrowicz. Polarization analysis of terahertz radiation generated by four-wave mixing in air. Optics Letters, 2008, 33 (11), pp.1195. ⟨10.1364/OL.33.001195⟩. ⟨hal-00454573⟩