C. Voigtländer, R. G. Krämer, T. A. Goebel, D. Richter, and S. Nolte, "Variable wavefront tuning with a SLM for tailored femtosecond fiber Bragg grating inscription," Opt. Lett. 41, 17 (2016)
We report on the inscription of fiber Bragg gratings using femtosecond laser pulses and the phase-mask technique. The wavefront of the inscription laser is variably tuned with a spatial light modulator (SLM). By applying Fresnel lenses with different focal lengths, the period of the fiber Bragg gratings could be shifted. A linear change of the grating period for a FBG inscribed with a third-order deformed wavefront and a quadratic-period behavior for a fourth-order wavefront could be verified experimentally for the first time.