Writing waveguide in pure fused silica with 1-kHz femtosecond laser

We have investigated the writing of waveguides in pure fused silica glass with femtosecond Ti:sapphire laser at 1 kHz repetition rate. The obtained results were compared for two writing configurations with pulse durations of 200 fs and 45 fs, and with different exposure energies and translation speeds of the sample. The magnitude of the refractive-index changes in the glass was measured as a function of light exposure, where index changes as large as 5×10-3 were achieved.