Investigation to planar optical waveguides based on oxidised porous silicon/PMMA-DR1 by dark mode spectroscopy method

Abstract

The oxidised porous silicon layer with high porosity is obtained by anodization process followed by fully oxidation step. The planar optical waveguides is fabricated by penetrating polymer polymethylmetacrylate (PMMA-DR1) into the oxidised porous silicon film. The core layer of waveguide is formed by impregnating polymer into pores of oxidised porous silicon using method of immersion sample into PMMA-DR1/toluene solution under ultrasonic agitation in our experiment. The thickness of core of planar waveguides is controlled within 4µm by choice suitable immersion time. The waveguides consist of a higher index core oxidized oxidised porous silicon /PMMA-DR1 layer and a lower index buffer oxidised porous silicon layer separating the core from a high index silicon substrate. Optical parameters of waveguides are characterized by the dark mode spectroscopy method. Both refractive index and thickness of oxidised porous silicon /PMMA-DR1 film are obtained simultaneously and with good accuracy by measuring the coupling angles at the prism at a wavelength of 633 nm.