Light propagation scattering in porous silicon nanocomposite waveguides
Résumé
Planar waveguides have been achieved from oxidised porous silicon layers (OPS) which have been impregnated by solvents, Congo Red (CR) dye and poly(p-phenylene vinylene) (PPV) polymer. Optical loss has been investigated by a simple technique based on surface optical scattering measurements. Optical loss has been studied as a function of the wavelength, impregnation type and CR concentration. The main sources of attenuation, such as absorption, scattering from interface roughness, scattering from nano- crystallites and modification of the refractive indexes after filling are discussed. Optical loss measured at 0.633 µm is about 1.8 dB/cm for the OPS waveguides The optical loss decreases with wavelength. Otherwise, the optical loss increases with the concentration of Congo Red dye which is absorbent at this wavelength.