REFLECTIVITY MEASUREMENTS OF BROAD-BAND STIMULATED BRILLOUIN-SCATTERING MIRRORS

A XeCl laser source of variable coherence length has been used to investigate stimulated Brillouin scattering in cyclohexane and methanol versus pump intensity. Peak intensity reflectivities of 48 and 55 percent have been measured in cyclohexane and methanol respectively at about 100 GW/cm2 by using a pumping beam with a bandwidth of 44 GHz. Competitive nonlinear processes reduce reflectivity at higher pump intensities. However, a poorer beam reconstruction has been observed. It has been found that the divergence of the Brillouin backscattered radiation was larger than that of the pumping beam.