Fibre gratings for high temperature sensor applications

Phosphosilicate fibre gratings can be stabilized at temperatures in excess of 500 degreesC for sensor applications by optimizing thermal and UV presensitization recipes. Furthermore, the use of 193 min presensitization prevents the formation of OH absorption bands, extending the use of fibre gratings across the entire wavelength spectrum. Gratings for operation at 700 degreesC retaining up to 70% reflectivity after 30 min are demonstrated.