Propagation in erbium and silicon codoped silica slab waveguides: analysis of gain

The feasibility of optical amplifying waveguides is investigated through the elaboration of silica films codoped with erbium ions and silicon nanograins. The waveguiding function is provided by the index contrast between the active and cladding layers whereas the amplification is achieved by an efficient interaction between silicon nanograins and erbium ions. Based on experimental results and theoretical studies, this paper aims at providing a detailed analysis of the optical gain expected in slab waveguides taking into account a lateral pumping scheme of the silicon nanograins, the energy transfer mechanism from silicon grains to erbium ions and finally the propagation equations within the active layer. The main parameters-such as erbium and silicon concentrations, device length and pumping power-have been examined.