Type II femtosecond laser writing of Bragg grating waveguides in bulk glass

Low-loss singlemode waveguides with inherent Bragg grating responses were laser written for the first time in a single process step. A periodic array of refractive index voxels were imprinted point-by-point in bulk borosilicate glass by a type II ultrafast laser photosensitivity interaction, yielding permanent grating-waveguides with 1550 nm Bragg reflection.