Optical gain in Er-doped SiO_(2)-TiO_(2) waveguides fabricated by the sol-gel technique

摘要

The sol-get technique is a highly flexible technique for fabrication of oxide glasses, and various researchers have previously reported fuorescence studies of Er-doped sol-gel films and monoliths. Here we report the fabrication of Er-doped strip-loaded sol-gel silicate waveguifes, using a silica-titania-alumina host cormposition, and Er concentrations up to ≈ 1.1 × 10~(20) Er~(3+) /cm~(3) for possible application in integrated optic waveguide amplifiers. We have obtained high fluorescence lifetimes (> 8 ms), propagation loss values of 0.6-0.75 dB/cm at 1330 nm. and Favourable fuorescence spectral shape. Relative gain levets up to l dB/cm were obtained. These results indicate that about half the Er ions effectively contribute to gain, suggesting segregation of the remaining ions in crystallites or clusters of some kind.