STIMULATED EMISSION FROM ALEXANDRITE (BeAl2O4:Cr3 + ).

A new laser material - alexandrite (BeAl//2O//4:Cr**3** plus ) - was investigated. Alexandrite crystals were grown from a molten mixture of BeO and Al//2O//3 taken in the stoichiometric ratio. The dimensions of the crystals reached 10 multiplied by 1 multiplied by 1cm. The absorption spectrum at 300 degree K consisted of U and Y bands with maxima at 420 and 550-600 nm and of narrow lines B, R prime //1//,//2//,//3, and B//1//,//2 at 465, 650-660, and 678. 46-680. 27 nm. Cooling to 77 degree K shifted the R//1//,//2 lines by 8 A toward shorter wavelengths. Stimulated emission of the R//1 line was observed at liquid nitrogen temperature. The stimulated emission wavelength was within the range 679. 86-680. 33 nm.