Oxidized porous silicon waveguides losses

The Oxidized Porous Silicon Waveguides (OPSWG) present the chance to realize waveguide in the visible range compatible with integrated circuit (IC) fabrication technology. In OPSWG the light is confined in dense silica surrounded by a buffer of porous oxidized silicon. In this paper some of the results of the European project OLSI N degrees 28.934 are discussed. The waveguides were fabricated using p-doped (100) and n-doped (100) and (111) silicon wafers to investigate the influence of the doping type and of silicon crystal orientation on the guiding properties and the thickness of the buffer layer was varied from 1 mum to 2.5 mum changing the anodization regimes and the propagation losses were measured. Two different topology of mask have been used to determine propagation and planar bending losses. Buried OPSWG. realized depositing one micron poly-silicon layer on top of waveguides, have been thermally treated and measurements have not shown a great difference in terms of propagation losses with surface OPSWG.