Interactions of high-irradiance CO2 laser beams with individual micron-sized water droplets

Recent experiments on the dynamics of laser-beam single aerosol droplet interactions are reviewed, and emphasis is placed on droplet superheating and plasma formation due to irradiation of absorbing aerosols with intense laser beams. It is shown that at high levels of irradiance, the plasma breakdown threshold is reached, and that the primary cause of droplet destruction is the generation of an intense plasma near the irradiated droplet. Observed delays in laser-induced explosions of water droplets are explained by homogeneous nucleation of vapor caused by superheating, and it is noted that energy and mass transport processes may be neglected.