PHASE-CONJUGATE REFLECTIVITY AND DIFFRACTION EFFICIENCY OF GAIN GRATINGS IN ND-YAG

It is shown that gain gratings can be used as efficient phase conjugate and diffractive optical elements. Experimental results are presented of saturable gain four-wave mixing in a Nd:YAG amplifier using orthogonally polarised pump beams of pulse duration 16 ns. Phase conjugate reflectivity and diffraction efficiency are measured for both the reflection and transmission grating cases. Results show a higher efficiency for the transmission geometry. Transient (pulsed) experimental results are compared to a steady state theory.