Characteristics of absorption and dispersion for rubidium D2 lines with the modulation transfer spectrum

Absorption and dispersion signals of D-2 lines of rubidium atoms in a vapor cell have been experimentally investigated with the modulation transfer spectrum (MTS). Normal dispersion was observed at the transitions of F-g --> F-e = F-g - 1 and F-g --> F-e = F-g; anomalous dispersion, at transitions of F-g --> F-e = F-g + 1; and crossover resonance, by the transitions of F-g --> F-e = F-g - 1 and F-g --> F-e = F-g. The signal lineshape of the MTS and the detector phase are addressed accurately. (C) 2003 Optical Society of America.