Two-step purely thermal ion-exchange technique for single-mode waveguide devices in glass

Two-step purely thermal ion-exchange technique using two monovalent ions for single-mode waveguides is proposed. Experiments show embedded waveguide structure below the surface of the glass, as computer simulation predicted. The insertion loss of the straight waveguide was less than 1 dB for 19mm long samples, at both λ = 1.3 μm and 1.55 μm.