Multiparameter Sensor Based on Single High-Order Fiber Bragg Grating Made With IR-Femtosecond Radiation in Single-Mode Fibers

Narrowband multiple high-order Bragg resonances from a single Bragg grating structure inscribed using a femtosecond IR laser and a 4.28 mum pitched phase mask are used to demonstrate a multiparameter sensor in standard low cutoff wavelength optical fiber. Six high reflectivity resonances that are observed in the wavelength range from 1 to 2 mum can be used to monitor up to six sensing parameters. Temperature and strain coefficients of the grating at each of the high-order Bragg resonances are evaluated.