Efficient wavelength-selective optical waveguiding in a silica layer containing Si nanocrystals

Abstract
The optical properties of a silica layer containing Si nanocrystals deposited onto fused quartz are studied with emphasis on optical waveguiding (WG) of the photoluminescence (PL). The WG layer was estimated to be 4.3 μm thick with a refractive index of 1.67. We observed efficient (long-distance) propagation of the PL light in the layer, the losses being below 1 cm−1 at 1000 nm. Efficient narrowing of the PL spectrum (down to 8 meV) was detected demonstrating spectral filtering by the waveguide.