Abstract
Hönl–London type approximation expressions are derived for transition strengths of the Ω′=0,1,2,3, ←Ω″=0 (Σ, Π, Δ and Φ←Σ) three-photon transitions for diatomic molecules belonging to Hund’s case (a) and intermediate (a)–(b) coupling schemes. These are used to demonstrate what may be seen and what may not be seen in three-photon absorption spectra. The forms are used to simulate room temperature (3+1)REMPI spectra of HBr, for different electronic transitions. The analysis as well as comparison with (2+1)REMPI spectra is used to demonstrate the usefulness of three-photon absorption spectroscopy to identify excited states and to derive spectroscopic parameters. A Rydberg state, not observed in single or two-photon absorption, with band origin 82 837 cm−1 was identified and analyzed for the first time. It was assigned as the L1Φ(3) ((σ2π3)5dδ)) state, (0,0) band.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
