Kyw Crystal As A New Material For Acousto-Optic Q-Switches

We designed a high-efficient acousto-optic Q-switch based on a potassium yttrium tungstate crystal (KY(WO4)(2)), or KYW. Isotropic acousto-optic interaction along NmNg plane of dielectric axes of the crystal was used. The Q-switch operated at the wavelength of 2.1 mu m of a Ho:YAG laser with the diffraction efficiency over 60% at the RF driving power of 20 W. No laser damage of the crystal with antireflection coatings was observed at 12 J/cm(2) fluence for nanosecond pulses.