Fabrication of Optical Waveguide in Glass by Laser-Induced Crystallization

Abstract

Homogeneous crystal lines were fabricated at the surface of 8Sm2O3.37Bi2O3.55B2O3 glass by irradiations of cw Nd: YAG laser (λ=1064 nm) with laser powers of 0.7-0.9 W and laser scanning speeds of 3-5 μm/s. It was confirmed from micro-Raman scattering spectra that the lines consist of nonlinear optical SmxBi1-xBO3 crystals showing second harmonic generations. The curved crystal lines with bending angles of 0∼90° were successfully written by just changing laser scanning directions. The light (λ=632.8 nm) transmission was confirmed for a crystal line (length: 850 μm) with two bending angles of ±30o, where significant light scattering losses were not observed at the bending points. We propose that the curved crystal lines written by YAG laser irradiations have a high potential for applications in optical waveguides.