CHROMIUM DIFFUSION IN LITHIUM-NIOBATE FOR ACTIVE OPTICAL WAVE-GUIDES

A method to fabricate chromium-doped lithium niobate substrates in whi ch the active ions are introduced by thermal diffusion from a film is reported. Chromium concentration depth profiles have been obtained by secondary-ion-mass spectrometry and the relevant diffusion parameters have been derived. Fluorescence spectrum and upper laser level lifetim e of chromium diffused proton-exchanged and chromium/titanium-diffused lithium niobate waveguides have been measured. A simple model has bee n used to estimate the performance of such structures as waveguide opt ical amplifiers and lasers. (C) 1995 American Institute of Physics.