Manufacturing of double-layered multimode optical waveguides in glass substrate

Double-layered multimode waveguides were fabricated in optical glass substrate, each layer being formed by melt salt ion-exchange(IE), and subsequent field-assisted ion-migration(FAIM). Characterization of the double-layered waveguide chips were performed by microscopic observation of waveguide cross-section, output pattern observation, and insertion loss and crosstalk measurement. Results shows that dimensions of waveguides core at top layer and bottom layer core are respectively 29 m19 m and 31 m20 m, and output pattern of waveguide at different layers are of nearly the same dimensions. Waveguide loss characterization show that propagation loss of waveguide at top layer and bottom layer are 1.000.32 dB/cm and 0.780.35 dB/cm, and crosstalk between neighbor waveguide at different layers is approximately 17.7 dB. Analysis demonstrate that interconnection density can be doubled by adopting double-layered waveguide, thus this kind of waveguide can be expected a promising prospect in improving EOCB performance.