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arXiv · 0710.2873

Sensitive multiplex spectroscopy in the molecular fingerprint 2.4 $μ$m region with a Cr^{2+}:ZnSe femtosecond laser

Evgeni Sorokin·Irina T. Sorokina·Julien Mandon·Guy Guelachvili·Nathalie Picqué
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Abstract

An ultrashort-pulse Cr^{2+}:ZnSe laser is a novel broadband source for sensitive high resolution molecular spectroscopy. A 130-fs pulse allows covering of up to 380 cm^-1 spectral domain around 2.4 $μ$m which is analyzed simultaneously with a 0.12 cm^-1 (3.6 GHz) resolution by a Fourier-transform spectrometer. Recorded in 13 s, from 70-cm length absorption around 4150 cm^-1, acetylene and ammonia spectra exhibit a 3800 signal-to-noise ratio and a 2.4*10^-7 cm^-1*Hz^-1/2 noise equivalent absorption coefficient at one second averaging per spectral element, suggesting a 0.2 ppbv detection level for HF molecule. With the widely practiced classical tungsten lamp source instead of the laser, identical spectra would have taken more than one hour.

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Evgeni Sorokin, Irina T. Sorokina, Julien Mandon, Guy Guelachvili, Nathalie Picqué. 2007-10-15. Sensitive multiplex spectroscopy in the molecular fingerprint 2.4 $μ$m region with a Cr^{2+}:ZnSe femtosecond laser. https://doi.org/10.1364/oe.15.016540

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