Stable formation of freestanding, submicron-thick tellurite glass film in molten glass lamella

Abstract This study investigates the thickness stabilization role of molten glass in the stable formation of tellurite glass film with submicron thickness. A tellurite glass balloon was formed by the glassblowing technique, then cooled to room temperature and cut into freestanding tellurite glass films. The fabrication conditions—blowing temperature, volume of introduced air, and inner pressure—were optimized for forming submicron-thick glass films with dimensions of 16 cm × 5 cm. The thickness reduced with increasing balloon size at 450 and 500°C, and was independent of the balloon size at 550°C. The formation mechanism of the tellurite glass film is apparently related to the surface tension gradient, which causes a compositional and structural change on the outermost surface of the molten glass. The tellurite films are potentially applicable as optical waveguides in next-generation optical circuits.