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 1 kHz. 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. Photoluminescence 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.