Efficient parametric light generators with intracavity pumping by the radiation of a garnet laser with a passive shutter

The characteristics of parametric light generators with intracavity pumping by the radiation of a garnet laser with a passive shutter have been experimentally investigated. The conversion efficiency of laser radiation with a wavelength of λp=1.064μm strongly depends on the characteristics of the phototropic shutter. When a radiation-colored LiF crystal with initial transmittance T0=0.25 is used in a parametric generator based on a potassium titanyl phosphate crystal at a wavelength of λs=1.91μm, a radiation energy of up to 10 mJ and a quantum efficiency of radiation conversion of Hq≈0.6 are achieved. When a YAG:Cr4+ shutter with T0=0.5 was used, the maximum radiation energy of the parametric generator was 5 mJ, while the conversion efficiency was Hq≈0.3-0.4. In a parametric generator based on potassium titanyl arsenate crystal with λs=1.55μm, the radiation energies corresponding to these shutters were about 7.5 and 5 mJ, while Hq≈0.4-0.6 and 0.25-0.4, respectively.