From filaments to light-sheets: tailoring the spectrum of fiber Bragg gratings with femtosecond lasers

Femtosecond laser light has been shaped with a spatial light modulator (SLM) to generate optically thin, aberration-free sheets of uniform intensity for inscription of fiber Bragg gratings (FBGs) inside the core of SMF-28 telecommunication fiber. The combination of flexible beam shaping and sheet-by-sheet writing offers facile means in controlling the coupling to cladding or radiation modes while facilitating spectral tuning flexibility that is not available with interference-based techniques. Spectral responses of uniform first order FBGs fabricated with single-pulse exposures are presented.