Pulse-shape dependence of stimulated-Brillouin-scattering phase-conjugation fidelity for high input energies

The shot-to-shot phase fidelity of a stimulated-Brillouin-scattering phase conjugator operated many times above threshold has been found to be very sensitive to the slope of the leading edge of the input pulse. For a pulse with a rising edge that is short relative to the acoustic lifetime of the stimulated-Brillouin-scattering medium, strong random fluctuations in the fidelity of the wave-front reversal are observed. However, by tailoring the leading edge of the pulse relative to the acoustic response time of the medium, good phase reproduction has been demonstrated for input energies of 100 times above threshold.