1-cm/sup 2/-size Er-doped waveguide based on bismuthate glass for compact amplifier with >15 dB gain at whole C-band

A 1-cm/sup 2/ size spiral Er-doped waveguide chip having gain values of >15 dB and output powers higher than 12 dBm at the whole C-band is realized by using a multicomponent bismuthate glass waveguide.