Light-to-heat conversion and heating of single nanoparticles, their assemblies, and the surrounding medium under laser pulses

Abstract

This review analyses the results of theoretical and experimental investigations of the thermal processes of the light-to-heat conversion and heating of single nanoparticles, their assemblies, and the surrounding medium under laser pulsed radiation, heat exchange and thermal conduction in a wide temporal interval from femtoseconds to CW action. Homogeneous metallic spherical nanoparticles are considered. The interaction of ultrashort laser pulses with an electron–lattice system in metallic nanoparticles is discussed and the novel results for electron–phonon coupling are presented. The conversion of radiation energy absorbed by nanoparticles into their thermal energy, nanoparticle heating and heat transfer to ambient medium are investigated. The temporal and spatial–temporal dependencies of nanoparticles and medium temperatures are reviewed, taking into account the dependencies of the thermo-optical parameters of the nanoparticles and surrounding medium on the temperature. The heat localization (thermal confinement) within the nanoparticle and nanoparticle assemblies during the determined time intervals, practically without heat exchange and with an ambience, is established and discussed. The redistribution of thermal energy between nanoparticles or nanoparticle assemblies and the surrounding medium during radiation heating and following cooling is considered. This review presents a platform for the description of the thermal processes of laser–nanoparticle interactions and their applications in photo-thermal nanotechnology, nanoenergy, laser processing of nanoparticles, laser nanomedicine, nonlinear optical diagnostics, and photochemistry.