High multiplexing capability and ultrahigh resolution interrogation for optical fiber Bragg grating sensing system

A high multiplexing capability and ultrahigh resolution interrogation scheme for optical fiber Bragg grating sensing system was proposed. A scan ring laser based on semiconductor optical amplifier (SOA) and tunable Fabry-Perot interferometer can provide 70nm bandwidth and 32 monitoring channels, and therefore the interrogator can simultaneously detect more than 1000 fiber Bragg grating (FBG) sensors. In the interrogation scheme, a gas absorption spectral line was used as a wavelength reference, and a comb filter was designed as a standard device that can dynamically calibrate the wavelength of FBG sensors. Therefore, the wavelength resolution can reach to 0.5 pm.