Fabrication of Bi2O3-based Er-doped waveguide for integrated optical amplifiers

We fabricated a 1 cm Bi₂O₃-based waveguide with Er and Yb concentration of 2.5 and 0.6 wt%. The fluorescence spectrum width of the core film due to the Er³⁺ transition of ⁴I₁₃2/-⁴I₁₅2/ is broader than that of conventional host glass such as SiO₂ and phosphate glass. The optical signal enhancement was observed with a forward pump power of 160 mW. The maximum enhancement was 5.7 dB at 1530 nm for the signal power of -10 dBm. At present, the concentration of Er³⁺ and Yb³⁺ ions and the length of the waveguides are not optimized. The waveguide loss and insertion loss are very large and have to be improved.