Laser manipulation of the size and shape of supported nanoparticles

Laser manipulation of the size and shape of metal nanoparticles prepared by self assembly of atoms on dielectric surfaces is discussed. The technique relies on the optical properties of the aggregates and the ability to remov e atoms from their surfaces by laser induced thermal evaporation. A theoret ical model which allows one to understand the basic mechanisms of the proce ss is presented. Furthermore, experiments are reviewed which demonstrate th at laser irradiation can be exploited for strong narrowing of initially bro ad size distributions yielding almost monodispersed samples and generation of aggregates with predetermined shape irrespective of their size. This mak es possible preparation of very special surfaces with novel physical and ch emical properties. Optical spectroscopy of the supported particles is demon strated to be a very sensitive tool for characterization of such adsorbate/ substrate systems, in particular for detection of laser induced modificatio ns of the nanostructured surfaces. Finally, prospects for future experiment s in this field and possible applications of the monodispersed systems are outlined.