Patterning and morphology of nonlinear optical GdxBi1-xBO3 crystals in CuO-doped glass by YAG laser irradiation

Dots and lines consisting of nonlinear optical GdxBi1-xBO3 crystals were patterned on the surface of CuO-doped Gd2O3-Bi2O3-B2O3 glass by heat-assisted (200 degrees C) Nd:YAG laser irradiations with a wavelength of lambda=1064 nm, where the laser energy absorbed by Cu2+ is converted to the local heating of the surrounding Cu2+. The surface morphology and orientation of crystals in the patterned lines were clarified from confocal scanning laser microscope observations and polarized micro-Raman scattering spectra. Crystal lines with periodic bumps (i.e., ladder-shape like lines) were patterned by laser irradiations with a power of 0.79 W and a scanning speed of 60 mu m/s, and the orientation of GdxBi1-xBO3 crystals in the lines was proposed. The present study demonstrates that the combination of Cu2+ and continuous wave Nd:YAG laser with lambda=1064 nm is effective in inducting crystallization of oxide glasses. The mechanism of laser-induced crystallization in glass has also been discussed.