Writing of nonlinear optical Sm2(MoO4)3 crystal lines at the surface of glass by samarium atom heat processing -: art. no. 123516

Some glasses such as 21.25Sm(2)O(3).63.75MoO(3).15B(2)O(3) (mol %) giving the formation of nonlinear optical Sm-2(MoO4)(3) crystals through conventional crystallization in an electric furnace and through continuous-wave Nd: yttrium aluminum garnet (YAG) laser (wavelength: 1064 nm) irradiation (samarium atom heat processing) have been developed. It is proposed from x-ray diffraction analyses, micro-Raman-scattering spectra, and second-harmonic generation measurements that the crystal structure of Sm-2(MoO4)(3) formed by the crystallization is the beta'-phase structure with an orthorhombic (noncentrosymmetric) symmetry. The lines consisting of nonlinear optical beta'-Sm-2(MoO4)(3) crystals are written at the surface of glasses by YAG laser irradiation (laser power: P=0.4 W, laser scanning speed: S=1-10 mu m/s), and, in particular, homogeneous crystal lines are formed at the laser scanning speed of 1 mu m/s. Refractive index changes (not crystallization) are also induced by YAG laser irradiation of P=0.4 W and a high laser scanning speed of S=25 mu m/s. The crystallization mechanism in the laser-irradiated region has been proposed. The present study demonstrates that the samarium atom heat processing is a technique for the writing of rare earth containing optical nonlinear/ferroelectric crystal lines in glass. (c) 2005 American Institute of Physics.