Control of ion-exchanged waveguide profiles with Ag thin-film sources

Fabrication of optical ion-exchanged glass waveguides by using thin-film silver ion sources is studied with reference to the use of salt-melt sources. Since the amount of silver in a thin-film source is limited, the process is source controlled, and it is shown that temperature and time as controlling parameters in the process can be replaced by source dimensions. Channel waveguide depth profiles are calculated. When contact film over patterned silver-film-stripe sources is used, silver can be used totally, which results in good uniformity in waveguide depth.