LINEAR AND NONLINEAR-OPTICAL RESPONSE OF BISMUTH AND ANTIMONY IMPLANTED FUSED-SILICA - ANNEALING EFFECTS

We report the linear and nonlinear optical response of bismuth and ant imony implanted fused silica with doses of 6 x 10(16) ions/cm(2). The nonlinear refractive index, n(2), was measured using a Z-scan techniqu e with a mode locked Ti:sapphire laser operating in 140 fs pulse durat ion at 770 nm wavelength. It is found that the nonlinear refractive in dex 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 l ager than that of Sb as-implanted sample. The large n(2) response is a ttributed to the presence of nanosized metal particles in the implante d layer observed by transmission electron microscopy. We also report t he changes of Linear and nonlinear optical response when implanted sam ples were subsequently annealed at temperatures from 500 to 1000 C in argon and oxygen atmospheres. The annealing effect on optical properti es is found to be strongly dependent on the annealing atmospheres. Our results indicate that annealing treatment in O-2 affects the local en vironment of the implanted metal ions and hence the linear and nonline ar optical properties of the metal-dielectric composite. We suggest th at a new phase of metal-oxygen-silicate was formed during annealing in O-2 atmosphere.