A model of laser-induced cavitation

Evaporation and plasma formation due to laser irradiation and subsequent expansion of the evaporated volume accompanying shock emission were studied theoretically as a phenomenon of laser-induced thermal breakdown rather than an optic breakdown. In recent years, this problem has become particularly important in the field of laser-mediated surgery. The Gilmore model of bubble dynamics based on the Kirkwood-Bethe hypothesis with proper initial conditions was used to calculate the shock pressure. This pressure depends on the radius and expansion velocity of the plasma formed by the laser irradiation. Subsequent bubble evolution after shock departure including the light emission at the collapse point was studied using the Keller-Miksis equation for the bubble wall motion and analytical solutions for the vapor inside the bubble. Calculation results show that the maximum size of the bubble and the half-width of the emitted power of the light pulse at the collapse point depend on the initial bubble radius and the bubble wall velocity. The light emission from the laser-induced bubble at the collapse point turns out to be black body radiation.