Vibrationally selective radiative and non-radiative transitions in gaseous hydrogen molecules

An efficient vibrationally selective technique to build-up the v″ = 1 vibrational levels in gaseous hydrogen is demonstrated using stimulated Raman pumping (SRP). Both photo-acoustic Raman spectroscopy (PARS) and coherent anti-Stokes Raman spectroscopy (CARS) are used to study non-radiative and radiative (v″ = 0 and v″ = 1) transitions in gaseous H2 molecules. The population fraction in the v″ = 1 vibrational level has been estimated using combined photo-acoustic and coherent anti-Stokes Raman spectroscopy with stimulated Raman pumping.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights► Environmental pollution problems: continuous monitoring of the leakage of inflammable gases is also required, such as H2, CH4 and H2S, chemical plants and along gas pipe-lines for health and safety reasons. ► PARS and CARS laser spectroscopic technique with SRP. ► It is particularly advantageous since a tunable infra-red laser is not required. ► Application in Combustion diagnostic Engineering and Technology.