Dependence of Hanle signals on the spectral distribution of the exciting light

2014 The shape of Hanle (zero field level crossing) signals may be strongly distorted if the spectral profile of the exciting light varies rapidly on the scale of the natural linewidth, provided that the Doppler width in the scattering region is not very large compared with the natural width. A Hanle experiment has been performed at the resonance line of calcium. The exciting light had a spectral profile with a very narrow hole at the resonance frequency and was produced by a calcium hollow-cathode with an absorbing atomic beam of calcium inserted in its light path, The observed level crossing signals are in very good agreement with theoretical predictions. LE JOURNAL DE PHYSIQUE TOME 36, JUILLET-AOÛT 1975, Classification Physics Abstracts 5.250