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

Silicate glass of system SiO2-B2O3-Al2O3-R'O-R2O(R'=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 10μm 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 8μm×8μm,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 1.55μm.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.