DIFFERENT TEMPORAL BEHAVIOR FOR THE FORWARD-CIRCULATING AND BACKWARD-CIRCULATING RADIATION WITHIN A MICRODROPLET

Spatially resolved nonlinear scattering of a train of picosecond pulse s from ethanol microdroplets is investigated. Different time behavior is observed for Light with the same and the opposite sense of circulat ion as the input-coupled light. The forward-circulating Light exhibits a smooth, delayed pulse-to-pulse growth, attributed to increased inpu t coupling with time induced by the laser pulses. The backward-circula ting light has an irregular time behavior, attributed to near-backward stimulated Brillouin scattering. Increased scattering as a result of CO2 (compared with He) dissolved gas is demonstrated by an intensity d ecrease of the spatially precessed radiation on a cavity resonance.