‘Fast’ highly efficient phase-conjugate mirror, based on InAs, in the cavity of a repetitively pulsed CO2 laser

Theoretical and experimental investigations were made of the temperature dependences (in the range 300 — 500 K) of the nonlinear susceptibility and of the linear and nonlinear absorption coefficients of InAs. The results were used to calculate the temperature dependence of the four-wave reflection efficiency. It was found that a phase-conjugate mirror, made of InAs 0.2 — 0.3 cm thick, was capable of a high reflection efficiency (exceeding 100%) when the crystal was heated to ~310 K. Thermally stable reflection with an efficiency of 30% — 50% was possible in the temperature range 300 — 500 K whnbsp;en the crystal thickness was 0.05 — 0.1 cm. A phase-conjugate mirror was constructed with a reflection efficiency exceeding 200%, when the pulse repetition rate was up to 12.5 Hz and the total number of pulses was up to 12. It should be possible to operate such a phase-conjugate mirror at pulse repetition rates up to ~100 Hz or higher.