Analysis of the bandwidth of resonant spectra for tilted fiber grating

Based on coupled mode equations, the formula of null null bandwidth for tilted fiber grating is deduced in this paper. Numerical simulations and theoretical analysis of the effects of the tilt angle on bandwidth and maximum reflectivity are performed. Furthermore, under the maximum reflection of 95%, the relation of bandwidth with modulation amplitude and length of grating, and the needed length of grating are demonstrated in two three dimensional diagrams. It reveals that the grating tilt can obviously narrow the bandwidth, especially in the case of large modulation amplitude and grating length, which is meaningful to its application on optical communication and fiber sensing.