Abstract: An additive, preferably in the form of metal nanoparticles or nanodomains, greatly improves a laser-based method and system for inducing optical breakdown. The use of ultrashort laser pulses to induce laser-induced breakdown (LIB) in metal nanoparticles or nanocomposites makes it possible to reduce significantly the threshold laser energy required for LIB. Such nanoscale (submicron) metallic particles allows one to control the LIB process. The nanoparticles can be synthesized so as to target specific biological structures or tissues (dendrimer nanoparticles are one system for which this has been demonstrated). This opens up the possibility of performing LIB for targeted cancer treatment or microsurgery.

Abstract: An acoustic monitoring method and system in laser-induced optical breakdown (LIOB) provides information which characterize material which is broken down, microbubbles in the material, and/or the microenvironment of the microbubbles. In one embodiment of the invention, femtosecond laser pulses are focused just inside the surface of a volume of aqueous solution which may include dendrimer nanocomposite (DNC) particles. A tightly focused, high frequency, single-element ultrasonic transducer is positioned such that its focus coincides axially and laterally with this laser focus. When optical breakdown occurs, a microbubble forms and a shock or pressure wave is emitted (i.e., acoustic emission). In addition to this acoustic signal, the microbubble may be actively probed with pulse-echo measurements from the same transducer. After the microbubble forms, received pulse-echo signals have an extra pulse, describing the microbubble location and providing a measure of axial microbubble size.

Abstract: An acoustic monitoring method and system in laser-induced optical breakdown (LIOB) provides information which characterize material which is broken down, microbubbles in the material, and/or the microenvironment of the microbubbles. In one embodiment of the invention, femtosecond laser pulses are focused just inside the surface of a volume of aqueous solution which may include dendrimer nanocomposite (DNC) particles. A tightly focused, high frequency, single-element ultrasonic transducer is positioned such that its focus coincides axially and laterally with this laser focus. When optical breakdown occurs, a microbubble forms and a shock or pressure wave is emitted (i.e., acoustic emission). In addition to this acoustic signal, the microbubble may be actively probed with pulse-echo measurements from the same transducer. After the microbubble forms, received pulse-echo signals have an extra pulse, describing the microbubble location and providing a measure of axial microbubble size.

Abstract: An additive, preferably in the form of metal nanoparticles or nanodomains, greatly improves a laser-based method and system for inducing optical breakdown. The use of ultrashort laser pulses to induce laser-induced breakdown (LIB) in metal nanoparticles or nanocomposites makes it possible to reduce significantly the threshold laser energy required for LIB. Such nanoscale (submicron) metallic particles allows one to control the LIB process. The nanoparticles can be synthesized so as to target specific biological structures or tissues (dendrimer nanoparticles are one system for which this has been demonstrated). This opens up the possibility of performing LIB for targeted cancer treatment or microsurgery.