Abstract

From particle heating-melting-evaporation model, proposed in [1], and further developed in our previous works [2,3], two critical regimes of irradiation of nanocolloid, "hard" and "soft" irradiation, can be determined. The first one corresponds to the conditions when particle into a colloid will be evaporated completely by one laser pulse. The second one corresponds to the conditions when particle into a colloid will be melted completely but not evaporated yet. In other words, if "hard" irradiation corresponds to full evaporation regime, the "soft" one corresponds to the threshold of particle evaporation. Both critical regimes depend on particular noble metal, particle size, shape and laser wavelength. Both ones can be calculated with classical thermodynamics approach. For example, "soft" laser fluence is depicted in Fig. 1 as the function of particle diameter for spherical silver and gold nanoparticles irradiated by fundamental wavelength, 2^nd and 3^rd harmonics of Nd:YAG laser.

© 2009 IEEE