A simultaneous interrogation system for intensity-type sensor/fiber Bragg grating/extrinsic Fabry?Perot interferometer

A simultaneous interrogation system for an intensity-type sensor, fiber Bragg grating and an extrinsic Fabry–Perot interferometer is demonstrated. The three types of sensors occupy different wavelengths ranging from 1524 nm to 1563 nm, and all sensors are wavelength-division multiplexed and interrogated in one demodulation system. Experimental results show that a wavelength resolution of 2 pm for fiber Bragg grating, a loss resolution of 0.1 dB for an intensity-type sensor and a cavity-length resolution of 3.5 nm for an extrinsic Fabry–Perot interferometer are obtained. The cross-talk between the different sensors is also examined.