摘要

We develop and demonstrate a non-balance Mach-Zehnder autocorrelator based quasi-distributed sensing network. A three-port optical fiber circulator is used to connect broadband light source, sensor array and autocorrelator, avoiding reflective light from sensor array reentering into the light source. At detection location, a balanced detection approach is employed for restraining beat noise of the low coherent interferometric sensing network by respectively connecting two photodetectors to the two output ports of the Mach-Zehnder autocorrelator. The characteristics of the unidirectional transmission and differential output detection can at least double the effective efficiency of the light source power. The optimization and signal-to-noise of the sensing system are theoretically discussed, and a thirteen-sensor network is experimentally demonstrated. The full-fiber and common-path sensing system with high signal-to-noise is quite suitable for quasi-distributed measurement of strain and temperature in smart structures.

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