Planar waveguide amplifier

摘要

The present invention provides a planar optical waveguide amplifier for amplifying optical communications signals when optically pumped by radiation of a pumping wavelength, the amplifier comprising: an optical buffer layer formed on a substantially planar substrate; an optically-transmissive metal-oxide-based waveguide core formed on the buffer layer, the core comprising aluminium oxide and a gain medium; and an optical cladding layer formed over the core. Preferably, the composition of the core predominantly comprises aluminium oxide and the gain medium comprises erbium and/or ytterbium. The waveguide core can be formed by reactively dc sputtering aluminium. The invention has the advantage of allowing higher erbium doping concentrations than is possible for silica-based amplifiers.