Strain characterization of fiber Bragg gratings inscribed by high-intensity femtosecond UV pulses

We report strain characterization of birefringent fiber Bragg gratings fabricated in hydrogen-free photosensitive Ge/B codoped PS1250/1500 fiber by high-intensity femtosecond 264 nm pulses. These anisotropic FBGs demonstrate high PDL value of 8 dB but, unlike the FBGs inscribed in PM fibers, show shape preservation under strain of [0, 700 mV] by interrogation based on broad-band source and optical spectrum analyzer.