Line-by-line femtosecond FBG inscription for innovative fiber lasers

We report the fabrication of fiber Bragg gratings (FBGs) in passive as well as doped fibers utilizing the femtosecond laser line-by-line technique. Narrow-linewidth linear gratings as well as broadband chirped gratings were inscribed into silica- and fluoride-glass optical fibers. Polarization-dependent characteristics of non-tilted and of 45°-tilted gratings are analyzed and the possibility of direct inscription into coated (i.e. non-stripped) fibers is demonstrated.