Planar optical waveguides formed by erbium ion exchange in glass

Abstract
We report the use of erbium ion as the sole dopant in the formation of planar optical waveguides on glass substrates through a simple ion exchange process. Index differences of more than 0.04 have been achieved. This offers the prospect of designing active optical waveguides free from the unwanted side effects of additional index-raising dopants currently used in the ion exchange process.