Erbium-doped silicate glasses for integrated optical amplifiers and lasers

Soda-lime silicate glasses doped with different percentages of Er- and Yb-oxides were produced by melting, and both planar and channel waveguides were fabricated by ion exchange. Pure potassium and diluted silver nitrate melts were used. The optical and spectroscopic properties of the various waveguides were investigated, and the results are reported here. The optical parameters such as refractive index, diffusion depth and number of modes were measured by dark-line spectroscopy. Absorption and fluorescence spectra were also recorded. Channel waveguides were produced by photolithographic patterning, using Al or Ti masking films. Particular attention was focused on two aspects: (a) the study of the spectroscopic properties as a function of Er3+/Yb3+ concentration; and (b) the shaping of the waveguide index profile by thermal annealing treatments. By using proper process parameters, net optical gain in the 1532-1555 nm band was measured in different samples, both in K+- and in Ag+-exchanged channel waveguides, upon pumping at 980 nm.