Poling of glass modified by femtosecond irradiation

Summary form only given. We have demonstrated a new technique for glass poling which involves femtosecond irradiation of the sample with subsequent thermal poling. We observed enhancement of second order nonlinearity in the treated regions. The technique was used for /spl chi//sup (2)/ grating fabrication. A grating of 20 /spl mu/m period and 4 /spl mu/m line width was written into a silica glass plate by scanning with the focused beam produced by an amplified Ti:sapphire laser operating at 850 nm, 150 fs pulse duration and 250 kHz repetition rate. Red luminescence was observed in the irradiated regions indicating that non-bridging oxygen defects were created. For normally incident irradiation of a single grating line, clear second harmonic lobes were observed.