THz generation by optical rectification and competition with other nonlinear processes

Zhen-Yu Zhao (1) , Sophie Hameau (1) , Michel Voos (1) , Jérôme Tignon (1)

1 LPA - Laboratoire Pierre Aigrain

We present a study of the terahertz (THz) generation by optical rectification in a 2 mm thick <110> ZnTe crystal. The conditions for the most efficient THz generation are described. We investigate the competition between optical rectification (OR), second harmonic generation (SHG), two-photon absorption (TPA) and free-carrier absorption in the diffraction limit, for excitation spot sizes smaller than the THz wavelength. We find that while free-carrier absorption contributes significantly to reduce the THz emission, this contribution does not depend on the excitation spot size. On the contrary, two-photon absorption induces a strong dependence of the THz emitted power for decreasing excitation sizes.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Zhen-Yu Zhao, Sophie Hameau, Michel Voos, Jérôme Tignon. THz generation by optical rectification and competition with other nonlinear processes. International Symposium on Space-Terahertz Technology, 2006, Paris, France. ⟨hal-00109941⟩