Net optical gain at 1.53 mm in an Er-doped phosphate glass waveguide on silicon

Er-doped planar optical waveguide amplifiers, operating at the third telecommunication window near 1.5mm [1], are attractive due to their small size and potential integration with other optical devices, for example, a passive splitter [2] or combiner [3] as loss-compensating components. Considerable effort is being made to realize Er-doped optical waveguide amplifiers. A wide range of materials from glasses to crystals has been investigated as erbium hosts, together with different waveguide fabricating techniques [4-8]. We report here on the gain characterization of a planar optical waveguide amplifier based on Er-doped phosphate glasses, fabricated by RF-sputtering techniques on oxidized silicon substrates. A net optical gain of 4.1 Polman dB has been achieved at a signal wavelength of 1535 nm in a 1-cm long Er-doped phosphate glass waveguide with 66 mW pump power at 980 nm.