Hypersonic phase-conjugation mirror for the reflection of high-power nanosecond pulses

A hypersonic phase conjugation (PC) mirror operating at four-wave mixing with a strong signal wave has been studied experimentally and theoretically. It is shown that at large gain increments the energy of the signal wave is transferred to the energy of the Stokes' reference wave which inhibits the attainment of a high signal reflection coefficient. Methods for discriminating the gain of the Stokes' signal and reference waves have been proposed and realized. The reflection coefficient of approximately 4 ns signal pulse was increased by energy up to 50% and by power up to approximately 100%. A PC-mirror used in an amplifier on 45 mm diameter neodymium silicate rods made it possible to obtain a pulse of about 2 ns duration, approximately 80 J energy, and a radiation divergence of approximately 10/sup -4/ rad (50% energy).<
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