Temporal And Spatial Characterization Of Optical Breakdown In A Suspension Of Small Absorbing Particles

Abstract

It has been shown that a suspension of small, absorbing particles in a liquid demonstrates nonlinear transmission when exposed to high-energy laser pulses. Two experiments were performed to characterize the nonlinear phenomena that occur. First, an HeNe probe beam and fast photodetector were used to monitor the transmission of the suspension as high-intensity Nd:YAG pulses passed through. The sequence of events in the breakdown process was thus determined. Second, the spatial distribution of the transmitted Nd:YAG pulses was monitored with a CCD camera and Quantex QX-7 digital image processor. The distribution of the light scattered by the suspension was viewed for input pulses less than, near to, and greater than the threshold required to produce breakdown. The combined results of these two experiments gives a clearer understanding of the limiting process that occurs.