Higly nonlinear optical composites obtained in silica and soda-lime glasses by Ti ion implantation and laser annealing

Titanium ions were implanted at the energy of 30 keV and fluence of 1 x 10(17) cm(-2) into fused silica and soda-lime glasses, X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) analyses showed the formation of titanium silicide clusters in the implanted region. Specimens were subsequently irradiated with high-power light pulses from a Nd:YAG laser, at various intensities. Above an intensity threshold, related to the actual absorbed energy, we observed that:(i) the light transmittance increased; (ii) silicon and titanium oxides formed at the expenses of titanium silicides, which, in turn, became titanium-rich; (iii) the value of the intensity-dependent refractive index had the same order of magnitude (10(-12) m(2)/W in the picosecond range) for both the as-implanted and the laser-irradiated samples. Mechanisms responsible for the observed behavior are discussed.