Nonlinear refractive index of fs-laser-written waveguides in fused silica

We report on the measurement of the nonlinear refractive index of fs- laser written waveguides in fused silica by analyzing self- phase modulation of the propagating light. The nonlinear index is reduced considerably compared to the bulk material by the writing process and is furthermore highly dependant on processing parameters. (c) 2006 Optical Society of America.