Graded-index surface or buried waveguides by ion exchange in glass.

Graded-index surface or buried waveguides have been realized by thermal or electrically induced ionic exchange in glass. Deep waveguides can be obtained up to 200 microm when Li(+) ions are used. Using Ag(+) ions, buried waveguides can be obtained with a maximum index at 80 microm into the substrate. Typical losses for these devices are 0.5 dB/cm. Maximum index variations can be tuned from 0 to 0.11.