Characterization of Nb/Al codoped silica fiber by writing long-period gratings with CO2 laser

In this paper, we report a long-period grating (LPG) in Nb/Al codoped silica fiber with CO2 laser pulse writing technology. The temperature and strain characteristics of this Nb/Al-LPG were studied experimentally. Based on the experimental results, the thermooptic coefficient and elastooptic coefficient of the core of the Nb/Al codoped fiber were evaluated to be 7.99 × 10−6/°C and −0.222.