Abstract

Resonance fluorescence of an atom is one of the mostimportant means of investigating radiation-matter interaction. When laser light at low intensity is resonantly scattered by anatom at rest, the frequency distribution of the fluorescentlight is limited only by the laser linewidth. The firstexperiment in which these theoretical predictions are confirmedwill be described. The atom at rest is provided by a trappedand laser-cooled Mg+ ion. The spectrum of the fluorescence ismeasured by heterodyning the emitted light with a sideband ofthe laser radiation. The fact that this experiment is nowpossible opens up a series of new measurements such asobservations of phase fluctuations or squeezing. Furthermorethe quantum motion of the trapped ion can be investigated viasidebands in the spectrum being of importance for therealization of quantum logic gates. The comparison of theheterodyne spectrum to photon correlation demonstratescomplementarity.

© 1996 Optical Society of America