Compositional redistribution in CaO-AlO-SiO glass induced by the migration of a steel microsphere due to continuous-wave-laser irradiation.

A high-power continuous-wave (CW) laser was used to move a steel microsphere through a CaO-AlO-SiO glass block at room temperature along a trajectory toward the laser source. A compositional analysis revealed that the CaO concentration in the glass decreased at the center of the microsphere's trajectory but increased in the area adjacent to it; the SiO concentration showed an opposite trend while the AlO concentration did not change. Further, the compositional difference between the center and the area adjacent to the microsphere trajectory depends on the velocity of the microsphere, which is controllable by tuning the laser power.