Abstract

The behavior of the line shape and the transition frequency of a Doppler-free two-photon transition in an atomic beam is an important consideration in precision spectroscopy and in laser stabilization applications. In a metastable atomic beam, the low metastable density coupled with the low two-photon transition probability require the use of high laser intensity. Thus, the dominant systematic effect is due to the ac Stark shift. Since the laser beam has a Gaussian profile, atoms excited in different regions of the profile will have different ac Stark shifts and different transition probabilities.¹

© 1992 Optical Society of America