Laser breakdown in alcohols and water induced by λ = 1064 nm nanosecond pulses

Laser breakdown, induced by nanosecond pulses of 1064 nm wavelength, was studied in four alcohols and in water. The time dependent structure and physical properties of the breakdown were measured at high temporal and spatial resolutions, using Mach–Zehnder interferometry, shadow and Schlieren diagnostic techniques. The results indicate that just after the laser pulse the spark column has essentially discrete character and in all liquids it consists of a train of plasma micro-balls, triggered by microscopic inclusion particles. At longer times, namely in a few nanoseconds, micro-bubbles and associated micro-spherical shockwaves appear. These structures and their time-evolution were measured. Warmed channels were observed in the focal volume in all studied liquids.