Effect of interface roughness and polarisation on the optical losses of porous silicon-based waveguides

Abstract

Optical losses measurements were performed at 1550 nm on both porous silicon ( P Si) and oxidised P Si ( OP Si) planar waveguides as a function of interface roughness. The P Si waveguides were produced at different anodisation temperatures to reduce the interface roughness. The authors noticed a decrease in optical losses with the diminution of roughness. The lowest value of optical losses was equal to 0.5 dB/cm and obtained for OP Si waveguide with a 10 nm interface roughness and anodisation temperature equal to 20 C. The surface scattering losses were modelled. There is a good agreement between the theoretical and experimental values. The optical losses were also carried out in transverse electric (TE) and transverse magnetic (TM) polarisations for both P Si and oxidised OP Si waveguides.