Energy optimisation of an Nd:YAG-based four-wave-mixing oscillator with feedback and investigation of its adaptive properties in the pulse-periodic regime

Theoretical and experimental optimisation was made of the parameters of an Nd:YAG oscillator based on four-wave mixing (FWMF) with feedback. Use was made of a thermal-nonlinearity hologram and the energy efficiency under conditions of generation of giant pulses was determined. The efficiency reached was 60% when the energy pulse was 200 mJ for a 2-mm input beam of 50 mJ energy. The ability of the system to operate in the pulse-periodic (up to 25 Hz) conditions was demonstrated.