Abstract

Long-period gratings (LPG) and fiber Bragg gratings (FBG) are widely used optical components in different areas: from spectral filtering in lasers to sensing applications [1]. Various methods for LPG and FBG writing are used including traditional UV modification of photosensitive fiber core. The main advantages of femtosecond laser writing in comparison with UV modification consist in possibility to modify non-photosensitive fibers through plastic coating and to obtain gratings with higher resistance to thermal decay [2]. Direct writing techniques by femtosecond laser pulses allows one to write fiber gratings with any geometry without the usage of additional optical components, such as phase mask and cylindrical lens. In this work the results of direct LPG and FBG writing in specialty fibers by high-energy femtosecond laser pulses are presented.

© 2015 IEEE