Femtosecond laser Fourier transform absorption spectroscopy

Julien Mandon (1) , Guy Guelachvili (1) , Nathalie Picqué (1) , Frédéric Druon (2) , Patrick Georges (2)

1 PPM - Laboratoire de Photophysique Moléculaire
2 Laboratoire Charles Fabry de l'Institut d'Optique / Elsa

A femtosecond mode-locked laser is used for the first time as a broadband infrared source for high resolution Fourier transform absorption spectroscopy. Demontration is made with a Cr^4+:YAG laser. The entire nu_1+nu_3 vibration-rotation band region of acetylene, observed after passing through a single pass 80-cm long cell, is simultaneously recorded between 1480 and 1600 nm, in 7.9 s with a signal to noise ratio equal to 1000. Two hot bands of the most abundant acetylene isotopologue and the n1+n3 band of the ^13C^12CH_2 are also present. The noise equivalent absorption coefficient at one second averaging is equal to 7 10^{-7} cm^{-1}.Hz^{-1/2} per spectral element.

Mots clés: molecular spectroscopy; Fourier transform spectroscopy; mode-locked lasers; Infrared and far-infrared lasers; ultrafast lasers

Domaines: Optique [physics.optics]

Julien Mandon, Guy Guelachvili, Nathalie Picqué, Frédéric Druon, Patrick Georges. Femtosecond laser Fourier transform absorption spectroscopy. Optics Letters, 2007, 32 (12), pp.1677-1679. ⟨hal-00136984⟩