Studies on passive and active silver–sodium ion-exchanged glass waveguides and devices

In this paper, we review our recent work on exploring and developing new techniques for planar lightwave circuits utilizing silver–sodium ion exchange. In the experiments, two special kinds of glass substrates have been used: aluminoborosilicate glass (also called BGG31) specially developed for passive ion-exchanged waveguides and phosphate glass (commercial name IOG-1) designed for waveguide laser applications. Phosphate glass can be doped with large amounts of rare earth ions without significant lifetime reduction. This enables fabrication of short-cavity waveguide lasers, a desirable feature for example in high-repetition rate modelocked lasers operating at 1550 nm wavelength region. Birefringence properties of buried molten salt ion-exchanged waveguides in BGG31 glass are presented in detail. Photosensitivity properties of both undoped and Er–Yb-codoped IOG-1 glass are discussed. A new approach to fabricate waveguide Bragg gratings through UV exposure in IOG-1 glass will be presented.