The Bragg grating sensor operation is shown in Figure 10
where light from a broadband source (LED) whose center
wavelength is close to the Bragg wavelength is launched
into the fiber. The light propagates through the grating, and
part of the signal is reflected at the Bragg wavelength. The
complimentary part of the process shows a small sliver of
signal removed from the total transmitted signal. This
obviously shows the Bragg grating to be an effective
optical filter [13].