Femtosecond Laser Induced Optical Waveguides and Micro-mirrors Inside Glasses

Optical waveguides and micro-mirrors have been successfully induced inside fused silica glass and k₉ glass, respectively, by focusing a 800 nm femtosecond (fs) pulsed laser with a repetition rate of 1kHz. The change of refractive index was determined to be 0.001-0.008 in the fused silica glass and 0.006 in the k₉ glass. The refractive index change is dependent on both the dose of irradiation and the power density of the fs pulsed laser. Photolumines-cence was observed in the irradiated region. and was attributed to the defects induced by fs laser irradiation. We discuss the relationship between the optical property and the luminescent property of the irradiated region.