Erbium-doped silica-based waveguide amplifier integrated with a 980/1530 nm WDM coupler

A high gain of 27 dB is achieved in an erbium-doped silica-based planar waveguide amplifier integrated with a directional coupler which multiplexes the signal and pump light. A low noise figure of 5.0 dB is attained with the planar amplifier by using an integrated coupler which is formed of erbium-doped silica-based waveguides.