We consider the mechanical forces exerted on atoms by light as a tool to make the atom more concrete as a particle. It can be pushed, trapped and observed in its own scattered light. Recent theoretical and experimental progress in the field of cooling and trapping of atoms demonstrates their palpable reality. The theory of the mechanical manifestations of light is reviewed, and its application to laser cooling is discussed. Traps for atoms are considered. The feasibility of pure light traps is discussed, and the use of other types of traps in laser applications is reviewed. We present briefly the main experiments proving the possibility of laser cooling and trapping. A brief discussion of applications and future experimental possibilities is given.
The basic ideas of the 'white-light' laser cooling and trapping are discussed and the applications to atom and ion cooling and trapping are presented. 'White-light' cooling allows one to maximize at the same time both the velocity capture range and the cooling rate. This give the possibility to improve the trapping collection efficiency, to reach lower temperatures in presence of strong heating processes, to cool and trap atoms by involving very narrow transitions from metastable levels. The definition and the realization of 'white' laser sources is presented and the improvements achieved with respect to the use of single mode lasers is demonstrated in the case of fast ions confined in a storage ring and in magneto-optical trapping of neutral atoms.