Patent ID: 7367948

Claim:
An acoustic monitoring method in laser-induced optical breakdown (LIOB) wherein an LIOB-induced microbubble is formed at an LIOB site, the method comprising the steps of: causing at least one acoustic wave reflected from the LIOB-induced microbubble at the LIOB site to propagate in a volume of material; detecting the at least one acoustic wave to obtain at least one signal from the LIOB site; and processing the at least one signal to obtain information which characterizes the material, the microbubble in the material or a microenvironment of the microbubble wherein the at least one acoustic wave includes an acoustic shock wave which propagates outwardly from an LIOB site and defines an acoustic point source wherein the point source is determined by location of an additive in the material wherein the additive enhances an electric field in the vicinity of the additive and wherein the information characterizes a photodisruption threshold of the material with the additive which is substantially lower than a photodisruption threshold of the material without the additive.