A novel fiber sensor array based on Sagnac interferometer with very simple electronic signal processing is proposed and experimentally demonstrated. A stable quadrature phase bias was obtained using a phase modulator, and polarization induced signal fading was suppressed by using a depolarizer and a broadband source. Phase sensitivity of about 4.0 μrad/\sqrt{Hz}$ at 5 kHz was obtained using a two-sensor array. Optical amplification experiments were also carried out for a two-sensor array based on Sagnac and Mach-Zehnder interferometers, respectively. From the measurement of phase sensitivity and noise analysis, the maximum number of sensors in an array under certain conditions could be predicted. In addition, it was found that an array with an EDFA at input port before interferometers shows better performance than with an EDFA at output port after interferometers. Theoretical simulation for three types of large-scale sensor arrays based on Sagnac, Michelson, and Mach-Zehnder interferometers was carried out. The results show that Sagnac and Michelson interferometer arrays have some unique properties compared with the conventional Mach-Zehnder case, especially in that there exist optimum values of Sagnac and Michelson array parameters that offer maximum sensitivity.
