Channel waveguides formed by germanium implantation in fused silica

Abstract

Low loss, single mode waveguides in fused silica have been formed by implantation with 5 MeV Ge ions. The implanted region was characterized by an increase in refractive index of ∼ 1.1%. The distribution of Ge as a function of depth showed a peak concentration of 3.9 mole % at a dose of 8 × 10 16 Ge/cm 2. This concentration profile of Ge was thermally stable to a temperature of ≥ 850°C. For doses in the range of 8 × 10 14−8 × 10 15 Ge/cm 2, the loss coefficient, α, was 1.0 dB/cm for the as-implanted waveguides and 0.10–0.15 dB/cm following annealing at 500°C measured at a wavelength of 1.3 μm.