Soft apertures for lasers emitting visible radiation

It was found that an Al₂O₃:Ti³⁺ crystal grown by the Verneuil method can be used in the fabrication of "soft" apertures for lasers emitting in the blue–green range. The experimental results indicated equalization of the intensity of the radiation across the laser beam and also "polychromatic" lasing when apertures made of Al₂O₃:Ti³⁺ were placed inside the resonator cavity.