Dispersion tailoring of femtosecond laser written chirped fiber Bragg gratings by selective femtosecond laser post-processing.

We present the tuning of the dispersion properties of a femtosecond (fs) laser inscribed chirped fiber Bragg grating (CFBG), realized by selectively modifying the refractive index of the already inscribed CFBG by fs laser post-processing. This Letter demonstrates for the first time, to the best of our knowledge, a flexible approach for tailoring higher-order dispersion terms of a fs inscribed CFBG via fs post-processing of selected grating regions, thus paving the way, e.g., for applications in dispersion management of ultrashort pulse fiber lasers.