Zeeman spectra of the à 1Au←X̃ 1Ag transition of trans-glyoxal studied by Doppler-free two-photon fluorescence excitation spectroscopy

Abstract

Doppler-free two-photon fluorescence excitation spectra of the A 1Au(v7′=1)←X 1Ag(v″=0) transition of trans-glyoxal were measured by propagating a laser beam either polarized parallel (π pump) or perpendicular (σ pump) to the magnetic field of 6 T. π pump and σ pump dependence of the Zeeman spectra of the Q(K)Q(J=6) lines for K=0–6 was measured. Intensities of the Zeeman components of the Q(6)Q(6) lines were observed to have the maxima at the high and low wave number ends and the minimum at the middle for π pump, and the minima at the high and low wave number ends and the maximum at the middle for σ pump. By comparing calculated and observed patterns of the Zeeman spectra, it became clear that the transition tensor M00 is dominant and the effective intermediate state is 1 1Bu(ππ*). K dependence of the Zeeman spectra of the Q(K)Q(J=15) lines was measured, and the Zeeman splittings were observed to increase proportionally to K2. J dependence of the Zeeman spectra of the Q(K=J)Q(J) lines was measured for J=...