Details

Autor(en) / Beteiligte

• Nordström, E.
• Bengtsson, P.-E.
• Marrocco, M.

Titel

Fourier-based approach to overcome anomalies in high-resolution spectra of vibrational CARS measurements of gases

Ist Teil von

• Journal of Raman spectroscopy, 2014-07, Vol.45 (7), p.489-494

Ort / Verlag

Bognor Regis: Blackwell Publishing Ltd

Erscheinungsjahr

2014

Quelle

Wiley Online Library

Beschreibungen/Notizen

• In this work, we report on an unconventional experimental procedure useful for thermometric measurements on the basis of high‐resolution vibrational coherent anti‐Stokes Raman scattering (CARS) generated using conventional lasers. The high spectral dispersion of 0.02 cm−1/pixel is achieved by means of some specific spectral arrangements (single‐mode pump laser and diffraction grating providing spectra at the sixth order) and is further strengthened by the use of a relay lens system mounted before the charge‐coupled device camera. Surprisingly, at the high spectral dispersion of our measurements, a significant and persistent thermometric inaccuracy is observed. The effect arises from an inevitable spectral modulation of defined frequency hidden in the main CARS signal of the gas under study, and to secure a good thermometric evaluation, we describe a Fourier approach that is experimentally demonstrated for the typical nitrogen CARS spectrum measured at room temperature. Copyright © 2014 John Wiley & Sons, Ltd. We report on an unconventional experimental procedure useful for thermometric measurements on the basis of high‐resolution vibrational coherent anti‐Stokes Raman scattering generated using conventional lasers. The unconventional procedure is needed to circumvent a spectral modulation appearing unexpectedly in typical N2 coherent anti‐Stokes Raman scattering spectra and causing relevant thermometric deviations.