Riedle, Eberhard; Moder, R.; Neusser, H. J.
Pulsed Doppler-free two-photon spectroscopy of polyatomic molecules.
In: Optics Communications, Vol. 43, No. 6: pp. 388-394
Doppler-free two-photon electronic spectra of a large polyatomic molecule are recorded for the first time with pulsed laser radiation of near Fourier-transform limited bandwidth (Δvnot, vert, similar100 MHz). The resolution obtained is sufficient to resolve individual rotational lines. Due to the high density of these rotational transitions a strong Doppler-broadened background is observed, which is, however, subtantially reduced by suitable choice of photon polarizations. Different vibronic bands of benzene (C6H6) are investigated and very accurate rotational constants are found.