Abstract

The one-atom maser or micromaser allows one to study the resonant interaction of a single atom with a single mode of a superconducting niobium cavity. In our experiments we achieve values of the quality factor of up to 3 ■ 10¹⁰, corresponding to an average lifetime of a photon in the cavity of 0,2 s. The photon lifetime is thus much longer than the interaction time of an atom with the maser field. The atoms used in the experiments are rubidium Rydberg atoms pumped by laser excitation into the upper maser level, 63 P_3/2, the lower maser level is either the 61 D_5/2 or the 61 D_3/2 depending on the cavity frequency. The atom field dynamics is observed by measuring the atoms in the upper or lower maser levels after the cavity. The field in the cavity consists only of single or a few photons. Nevertheless, it is possible to study the interaction in detail. Thus, the dynamics of the interaction described by the Jaynes- Cummings model can be investigated by changing the velocity i.e. the interaction time of the atoms. The population statistics allows to measure the non-classical character of the cavity field.

© 1998 IEEE