Abstract

Rydberg atoms are well known to have an extremely strong coupling to the electromagnetic field¹,², allowing experiments with only a few numbers of photons and atoms³. We use a 3-step excitation to pump rubidium atoms into the 62F level (Fig.1). The atoms traverse a superconducting niobium ring resonator, where they interact with a microwave field (Fig.2). Its frequency as well as the cavity may be tuned to resonance at 18.2 GHz with the 62F-64D transition, which yields a dipole moment of approx. 1570 ea_O. Time-of-flight broadening of about 100 kHz leads to a saturation photon number of the order of 10.

© 1988 Optical Society of America