Self-organized homo-epitaxial growth in nonlinear optical BaAlBO3F2 crystal crossing lines patterned by laser in glass

•BaAlBO3F2 crystal lines were patterned at the glass surface by lasers.•Crystal lines were crossing, bending, and spiral shapes.•Crystal orientation was determined by birefringence images.•Highly c-axis oriented crystal lines were patterned.•The model of self-organized homo-epitaxial growth was proposed.

Crystallization processing of glasses is important as a novel technique for the development of new optical materials, and laser-induced crystallization provides a new challenge in science and technology of materials. Nonlinear optical BaAlBO3F2 crystal lines with crossing, bending, and spiral shapes were patterned at the surface of 2NiO–49BaF2–24.5Al2O3–24.5B2O3 (mol%) and 2.9NiO–48.5BaF2–24.3Al2O3–24.3B2O3 (mol%) glasses by laser irradiation (Yb:YVO4 laser with a wavelength of 1080 nm) and the orientation state of BaAlBO3F2 crystals was examined from birefringence image observations. The birefringence images indicate that the growth of highly c-axis oriented BaAlBO3F2 crystals follows along the laser scanning direction even if the laser scanning direction changes, and in particular the direction of the c-axis of BaAlBO3F2 crystals changes gradually at the crossing and bending points. The model of “self-organized homo-epitaxial growth” is proposed for the crystal orientation at the crossing and bending points, as a new crystal growth science and engineering beyond the wise providence of nature.

Graphical abstractThis figure shows a schematic illustration for the crystal growth direction in the crossing lines, which is a model of self-organized homo-epitaxial growth in laser-patterned crystal lines proposed in this study.Figure optionsDownload full-size imageDownload high-quality image (100 K)Download as PowerPoint slide