OPTOACOUSTIC DETECTION OF MICROPARTICLES IN LIQUIDS AT LASER FLUENCESBELOW THE OPTICAL-BREAKDOWN THRESHOLD

An optoacoustic device consisting of a XeCl excimer laser and a measur ement cell with an attached piezotransducer was used for detecting mic roparticles suspended in liquid probes. The potential of optoacoustic diagnostics of microinhomogeneous liquids was enhanced by applying inf ormative parameters of optoacoustic response. Probes of distilled wate r and Dow Chemical latex suspension were used in experiments. It was s hown that cavitation mechanism of optoacoustic conversion taking place at laser fluences below the optical breakdown threshold was well-suit ed for individual microparticle detection. The approach proposed is di fferent from the well-known breakdown counting optoacoustic technique.