Channel waveguides formed by germanium implantation in fused silica

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 similar to 1.1%. The distribution of Ge as a function of depth showed a peak concentration of 3.9 mole % at a dose of 8 x 10(16) Ge/cm(2). This concentration profile of Ge was thermally stable to a temperature of greater than or equal to 850 degrees C. For doses in the range of 8 x 10(14)-8 x 10(15) Ge/cm(2), the loss coefficient, cu, was 1.0 dB/cm for the as-implanted waveguides and 0.10-0.15 dB/cm following annealing at 500 degrees C measured at a wavelength of 1.3 mu m.