SBS self-phase conjugation of CW Nd:YAG laser radiation in an optical fibre

Summary form only given. It's known since the 1970's that stimulated Brillouin scattering (SBS), through its phase conjugation (PC) properties, provides an effective means for beam clean-up of moderate to high power pulsed lasers, and recently demonstrated for average power in the kW range for repetitive mode operation. We report the observation and characterisation of high fidelity PC via SBS of CW laser radiation in multimode silica fibre (core/ cladding diameters 50/125 mm, numerical aperture 0.1, attenuation of -1 dB/km). A 5x microscope lens was used to launch the pump signal from single mode CW Nd:YAG laser into the fibre, the ends of which were cleaved.