New optical nonlinear crystallized glasses and YAG laser-induced crystalline dot formation in rare-earth bismuth borate system

New optical nonlinear transparent surface crystallized glasses have been successfully fabricated in the system of Ln(2)O(3)-Bi2O3-B2O3 (Ln = La, Sm, Gd). The second harmonic (SH) generation from the crystalline phases at the surface layers has been confirmed from Maker fringe measurements. It is suggested that the optical nonlinear crystals precipitated through the crystallization of Ln(2)O(3)-Bi2O3-B2O3 glasses would be new metastable Bi(x)Ln(1-x)BO(3) phases in which Bi3+ ions in BiBO3 are substituted by Ln(3+) ions. The thickness of crystallized surface was approximately 5 pin and SH intensity was 0.02 compared with that of the Z-cut alpha-quartz with a thickness of 0.6 mm. In 12.5Sm(2)O(3) . 30Bi(2)O(3) . 57.5B(2)O(3) glass, the crystalline dots with diameters of 5-65 mum are formed by the irradiation of CW YAG laser with a wavelength of 1064 nm (at 0.6 and 0.7 W, for 1-240 s), and it is found that these crystalline dots generate optical SH waves. This is the first finding on optical nonlinear crystalline dot formation by YAG laser irradiation in bismuth-containing glasses. (C) 2002 Elsevier Science B.V. All rights reserved.