Abstract

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

© 2008 Optical Society of America

Portraying polarization state of terahertz pulse generated by a two-color laser field in air

Yizhu Zhang, Yanping Chen, Shengqi Xu, Hui Lian, Mingwei Wang, Weiwei Liu, See Leang Chin, and Guoguang Mu
Opt. Lett. 34(18) 2841-2843 (2009)

Intense terahertz pulses by four-wave rectification in air

D. J. Cook and R. M. Hochstrasser
Opt. Lett. 25(16) 1210-1212 (2000)

Terahertz-pulse generation by photoionization of air with laser pulses composed of both fundamental and second-harmonic waves

Markus Kress, Torsten Löffler, Susanne Eden, Mark Thomson, and Hartmut G. Roskos
Opt. Lett. 29(10) 1120-1122 (2004)

Polarization of terahertz radiation from laser generated plasma filaments

Daniel Dietze, Juraj Darmo, Stefan Roither, Audrius Pugzlys, James N. Heyman, and Karl Unterrainer
J. Opt. Soc. Am. B 26(11) 2016-2027 (2009)

Generation of sub-two-cycle mid-infrared pulses by four-wave mixing through filamentation in air

Takao Fuji and Toshinori Suzuki
Opt. Lett. 32(22) 3330-3332 (2007)