High-contrast pump-probe spectroscopy with high-order harmonics

Y Mairesse (1) , W Boutu (2) , P Breger (2) , E Constant (1) , D Descamps (1) , N Dudovich (3) , B Fabre (1) , Stefan Haessler (2) , J Higuet (1) , E Mével (1) , S Petit (1) , Pascal Salières (2) , David Villeneuve (4) , P. B. Corkum (4)

1 CELIA - Centre d'Etudes Lasers Intenses et Applications
2 SPAM - Service des Photons, Atomes et Molécules
3 Department of Physics of Complex System
4 Steacie Institute of Molecular Sciences

The high order harmonic generation process from molecules can be used to probe the structure of the emitting medium with high spatial resolution[1,2]. The measurements of molecular dynamics with such a probe is thus very appealing. Contrast is an important issue in pump probe spectroscopy: in general the probe only excites part of the molecules, so that the detected signal can be dominated by contributions from non-excited molecules. In this article we review two techniques that can be used to enhance the contrast of pump probe measurements: transient grating spectroscopy and polarization-resolved spectroscopy. We use these techniques to detect rotational wavepackets and demonstrate a dramatic improvement in the contrast of the measured signal.

Domaines: Physique [physics]; Physique Atomique [physics.atom-ph]; Optique [physics.optics]

Y Mairesse, W Boutu, P Breger, E Constant, D Descamps, et al. (Dir.). High-contrast pump-probe spectroscopy with high-order harmonics. EDP Sciences, pp.107-111, 2009, UVX 2008, ⟨10.1051/uvx/2009017⟩. ⟨hal-01164784⟩