Light guiding in oxidised porous silicon optical waveguides

Oxidised porous silicon optical waveguides (OPSWG) are fabricated and characterised. Porous silicon, selectively formed on boron-doped silicon substrates, is oxidised in order to obtain a channel SiO2 optical waveguide. Light confinement within the guide is obtained by a decreasing profile of the refractive index of the oxidised porous silicon from the centre of the guide toward the surrounding silicon. Light guiding is observed in the whole visible range. Out-of-plane scattering and near-field profile are measured. A Scanning Electron Microscopy (SEM) micrograph of the resulting waveguide is shown. OPSWG are promising as silicon technology optical links for optoelectronic interconnections in VLSI integrated circuits. (C) 1997 Elsevier Science S.A.