Linear and nonlinear optical response of bismuth and antimony implanted fused silica: annealing effects

Abstract

We report the linear and nonlinear optical response of bismuth and antimony implanted fused silica with doses of 6 × 10 16 ions/cm 2. The nonlinear refractive index, n 2, was measured using a Z-scan technique with a mode locked Ti:sapphire laser operating in 140 fs pulse duration at 770 nm wavelength. It is found that the nonlinear refractive index n 2 of as-implanted samples is large, in the order of 10 −10 cm 2/W and the n 2 value of Bi as-implanted sample is about 2.4 times lager than that of Sb as-implanted sample. The large n 2 response is attributed to the presence of nanosized metal particles in the implanted layer observed by transmission electron microscopy. We also report the changes of linear and nonlinear optical response when implanted samples were subsequently annealed at temperatures from 500 to 1000 C in argon and oxygen atmospheres. The annealing effect on optical properties is found to be strongly dependent on the annealing atmospheres. Our results indicate that annealing treatment in O 2 affects the local environment of the implanted metal ions and hence the linear and nonlinear optical properties of the metal-dielectric composite. We suggest that a new phase of metal-oxygen-silicate was formed during annealing in O 2 atmosphere.