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.