Polarized fluorescence and the Hanle effect in NH2

Abstract

Polarized fluorescence spectra of gaseous NH₂, produced in a flow cell and excited by a tunable cw dye laser, have been observed. The measured degree of polarization of fluorescence agrees qualitatively with the values predicted by a model which does not include fine or hyperfine effects. Transitions originating from collisionally populated levels have also been observed to be polarized. The Hanle effect has been measured in several rotational levels of the (0,10,0) Π vibronic state of the ²A₁ electronic state and the present analysis of the data yields a value of ∼350 nsec for the radiative lifetime of these levels and indicates a decrease in the depolarization cross section with increasing rotational angular momentum.