Waveguide properties of optical structures fabricated by oxidation of porous silicon

Results of an investigation of the optical properties of channel waveguides fabricated by oxidation of porous silicon are described. The waveguide parameters are estimated and the existence of optical anisotropy is established. The effective refractive index of the dominant quasi-TM waveguide mode is measured. The results suggest that a buffer layer exists between the waveguide and the silicon substrate. It is hypothesized that a second refractive index peak exists within this layer.