Fiber optic Bragg grating demodulator and sensor incorporating same

摘要

A tapped Bragg grating is used to demodulate optical signals reflected by fiber optic Bragg gratings in a sensor in which the line spacings in the fiber optic Bragg gratings vary in response to a mechanical stress. A light detector, or light detector array is used to detect variation in the angular pattern of the light scattered by the tapped Bragg grating. Arrangements of mirrors, or alternatively arrangements of lenses, are used to concentrate the scattered light toward the light detectors and to enhance the angular changes in the scattered light.