Theoretical and experimental study on white light interferometric sensing network with double-ring topology

Abstract

A white-light interferometric fiber-optic sensing network based on the double-ring topology is demonstrated, which can be applied to the measurements of quasi-distributed strain and temperature in a smart structure. In order to increase the multiplexing capacity, decrease the measurement cost of each sensor, and improve the ability of reliability of the sensor network, a double-port interrogating technology was used. The double- ring fiber optical sensing network based on the space division multiplexing (SDM) is further developed. The low coherent multiplexing principle in the double-ring network structure is analyzed. Based on the optical path matching condition of SDM, the intensity characteristic of the interference signal in the sensor is deduced. The characteristics of the double-ring sensing network connecting 9 sensors and its property of robust resisting destruction are verified by experiments, and the results are analyzed and discussed.