Results of an experimental investigation of phase conjugation by stimulated Brillouin scattering (SBS) at 1.053 pm using a focused beam geometry with very long pulse lengths (pulse length > 6700 phonon lifetimes) are reported.Scanning of the beam through the SBS medium is proposed as a means of suppressing the undesirable effects of processes which can compete with the SBS in the long -pulse regime. Data taken with and without beam scanning indicate that high -quality phase conjugation can be achieved by SBS using focused beams with arbitrarily long pump pulses.

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