Direct fabrication of waveguiding structures with a femtosecond laser

We report the characterization of waveguiding devices fabricated in optical materials using a femtosecond pulse train from a Ti:Sapphire laser at a 25 MHz repetition rate. Both interferometry and micro-thermal analysis have been used as diagnostics to evaluate optical and structural changes within the glass matrix. A free-electron model is developed to explain the refractive index change.