On-chip fabrication of air-bubble-containing Nd3+-doped tellurite glass microsphere for laser emission

Abstract

We fabricated an air-bubble-containing glass microsphere on a substrate by using localized heating technique. Nd3+-doped tellurite glass cullets on a substrate were melted by a CW-Ti:sapphire laser at the wavelength of 810 nm and with the power density of more than 4.8 MW/cm2 to obtain tellurite glass microspheres with the diameter of 5 to 200 μm. The localized heating technique using laser is useful to form a bubble at a certain place in the microsphere. Both air-bubble-containing and bubble-free spheres showed lasing actions at around the wavelength of 1065 nm. The average laser thresholds of the air-bubble-containing and bubble-free microspheres with the size of 20-50 μm were 0.78 mW and 5.25 mW, respectively.