Femtosecond laser pulse written Volume Bragg Gratings Daniel Richter, Christian Voigtländer, Ria G. Krämer, Jens U. Thomas, Andreas Tünnermann and Stefan Nolte MATEC Web of Conferences, 8 (2013) 06014 Published online: 18 November 2013 DOI: 10.1051/matecconf/20130806014