Raman Excitation of Hydrogen Molecules to v = 1 State

Abstract

Coherent anti-Stokes Raman scattering (CARS) can reveal a molecule’s vibrational spectrum to a great extent. Instantaneous interaction of Stokes and pump beams stemming from powerful pulsed lasers excites a molecule’s vibrational modes in CARS. In this technique, combining two visible laser beams could create spectra resonances relating to vibrational transitions. In this work, Raman excitation of Hydrogen molecules to v = 1 state is achieved by CARS spectroscopy. CARS measurements are successfully carried out for H2 S-branch and Q-branch transitions using our laser system. This measurement proves the feasibility of CARS experiment which could be employed to excite molecules to a specific rovibrational state. Moreover, experiments conducted for CARS signal with respect to various gas pressures differing between 200 and 600 torr for S-branch transition of H2 molecule.