Behavior of a uniform fiber Bragg grating under impulsive strain

The article contains the analysis of influence of the length of a uniform fiber Bragg grating on the accuracy of transducing an impulsive strain. Using the matrix description of the grating, derived from the coupled mode theory, the waveforms were calculated of the power spectrum of the beam reflected by the grating, caused by the strain impulse propagating along it. On the basis of the introduced centroidal frequency of the grating, the mean square transducing error of the grating was calculated, as a function of the ratio of its length to the strain length, for rectangular, triangular, half-sinusoidal and trapezoidal strain impulses. This error was also calculated depending on full width at half maximum.