Laser-induced heating of a medium around light-absorbing nanoparticles

Pulsed photothermal bulk heating of the suspension of gold nanoparticles (spheres, rods, and shells) was found to have two different patterns: quasi-homogenous heating at low laser fluence when no bubbles emerge and 'no bulk heating' effect at higher fluence when the vapor bubbles are generated around gold nanoparticles. Time-resolved imaging and thermal lens methods yielded no detectible bulk heating outside the bubbles despite an increased release of thermal energy by the nanoparticles, which is different from the thermal behaviour of homogenous absorbing fluids. (authors)