Ultrafast laser plasma doping of Er3+ ions in silica-on-silicon for optical waveguiding applications

An ultrafast laser plasma doping (ULPD) technique is used for high concentration doping of erbium ions into silica-on-silicon substrate. The method uses a femtosecond laser to ablate material from TeO2-ZnONa2O-Er2O3 (Er-TZN) target glass. The laser generated plasma modifies the silica network, producing high index contrast optical layer suited to the production of on-chip integrated optical circuits. Cross-sectional analysis using scanning electron microscope with energy dispersive xray spectroscopy revealed homogeneous intermixing of the host silica with Er-TZN, which is unique to ULPD. The highly doped layer exhibits spectroscopic characteristics of erbium with photoluminescence lifetimes ranging from 10.79 ms to 14.07 ms.