MULTIPLE STIMULATED BRILLOUIN SCATTERING FROM A LIQUID WITHIN A LASER CAVITY

Abstract
By inserting a liquid cell between the ruby and the output reflector of a high power, passively Q‐switched ruby laser, marked changes in pulse shape, output power and spectral characteristics were observed. These effects are explained in terms of stimulated Brillouin scattering, from the liquid, effectively replacing reflection from the output mirror above a well‐defined power level. Time‐resolved Fabry‐Perot interferograms confirm this explanation and reveal that the output actually consists of a number of pulses, overlapping in time and corresponding to successive Brillouin orders.