CAVITY QUANTUM ELECTRODYNAMICS WITH STRONG-COUPLING IN THE OPTICAL DOMAIN

A tutorial review is given on recent experiments performed with I less -than-or-equal-to N less-than-or-equal-to 110 atoms in a microscopic h igh-finesse optical cavity. The resonator has length 1 mm and finesse 80000. The radiative properties of the strongly coupled atom-cavity sy stem differ from those of the individual components. For example, spon taneous emission is reversible, the first excited state of the composi te system splits into two levels and the intensity fluctuations of the light transmitted by the resonator are nonclassical. We observe photo n-antibunching and sub-Poissonian photon statistics. In terms of pract ical applications, the system renders possible (i) the detection of si ngle atoms with high sensitivity and (ii) optical bistability for a fe w atoms and photons only.