Fiber Bragg grating array sensor system using a bandpass wavelength division multiplexer and interferometric detection

A multiplexing approach for high-resolution sensing with Bragg gatings is described. The scheme uses a band-pass wavelength division multiplexer to separate the returned wavelengths from an array of gratings, and interferometric processing to attain high-strain resolution. A strain resolution of 1.5 nanostrain//spl radic/Hz is demonstrated, with a sensor bandwidth of 10 Hz-2 kHz for four sensors.