Refractive index sensitivity of fiber Bragg grating inscribed in a multimode fiber

Experimental results of refractive index sensitivity of etched fiber Bragg gratings inscribed in multimode fibers are presented in this work. The response of gratings to environmental refractive index changes is investigated by gratings immersion into glycerin-water blends with several concentrations. This study concludes that refractive index sensitivity of etched fiber Bragg gratings inscribed in multimode fibers are higher than the one found at etched fiber Bragg grating inscribed in single-mode fibers. Greater multimode core diameter enables Bragg gratings to exhibit enhanced sensitivity without requiring further fiber diameter reduction.