INTENSITY-DEPENDENT FEATURES IN HYDROGEN-BUFFERED CESIUM SPECTRA

Abstract

We report the observation of a spectral feature, namely a dip (peak) in transmission (fluorescence) excitation spectra of a room temperature cesium cell with addition of 20 Torr of H 2 appearing between Doppler-broadened F g =3 - F e =2,3,4 and F g =4 - F e =3,4,5 hyperfine transition groups of Cs D 2 line when laser radiation intensity exceeds 10 mW/cm2. In the experiment we have implemented frequency modulation of the diode laser radiation with lock-in detection of the transmission and fluorescence signals. Spectra taken at different intensities are presented and compared with the spectra without the buffer gas. Possible physical mechanisms responsible for the observed distinction are discussed.