Manufacturing and Analysis of Low-loss Ion-exchanged Glass-based Waveguide

Silicate glass of system SiO2-B2O3-Al2O3-R ˉO-R2O￡¨R ˉ=Ca, Mg; R=Na, K￡ was designed and melted for ion-exchanged integrated optical waveguide chip, on consideration of the suitability of ion-exchange and ion-diffusion process on this glass substrate, buried channel waveguide was manufactured by Ag+/Na+ ion-exchange in mixed melted salts, and subsequently field-assisted ion-diffusion process. Observation of optical microscope and electron microprobe show that Ag+ diffusion zone is driven to approximately 10| under the glass substrate surface. The Ag+ diffusion zone possesses higher refractive index than glass substrate, and thus acts as the waveguide core. This waveguide core is typically in dimension of 8| | , matching well with that of single-mode-fiber core, which ensures a low coupling loss. Propagation loss and coupling loss with single-mode-fiber is measured to be 0.1dB/cm and 0.2-0.3dB/facet respectively, at the wavelength of 1.55| . The propagation loss is very close to glass material inhere loss at the same wavelength, a typical characteristics of buried waveguide. It shows that the waveguide manufacturing process is promising for implementation of low-loss integrated optical devices.