Er 3+/Yb3+- codoped soda-lime silicate glasses: a case study

Silicate glasses are among the best hosts for rare-earth ions, especially for the development of integrated optic amplifiers and lasers, due to their chemical robustness and adaptability to different waveguide fabrication processes. We performed a detailed study of a set of six experimental soda-lime silicate glasses, all having approximately the same base composition but doped with different percentages of Er3+ and Yb3+ ions. Judd-Ofelt analysis was performed on these glasses and the calculated radiative lifetimes were compared with the experimental ones. Planar waveguides were fabricated by using ion-exchange technology, and a new analytical function was used to fit the index profile of the waveguides. Luminescence and Raman spectroscopy was performed on most waveguide samples, and upconversion emission was evaluated. Channel waveguide insertion losses were reduced by using annealing processes, and net gain around 1535 nm was obtained. The gain, so far, is limited, but we are confident to be able to further increase the amplifier performances. Meanwhile, we are also developing a new type of silicate glass doped with alumina in order to increase the gain bandwidth