Formation of optical coupling structure between two ends of silica glass optical fibers by inserting tellurite glass melt

Several nano liters of tellurite glass melt was inserted and quenched between two ends of silica glass optical fibers to form a optical coupling structure, whose length was several hundred micron meters. Dispite the large gap of thermal expansion coefficient between these glass materials, neither fracture nor bubbles were observed, which usually lead to a large optical propagation loss. The insertion was less than 10dB, which was mainly due to the lack of an optical waveguide structure in the tellurite glass segment. Further loss decrease is expected to be possible by introducing a refractive index modulation.