Distributed sensor and method using coherence multiplexing of fiber-optic interferometric sensors

摘要: A distributed sensor system including an optical source having a short coherence length for optionally continuously monitoring each in the system. In one preferred embodiment, array of fiber-optic sensors are organized ladder configuration, with positioned spaced relation and defining rungs ladder. Light transmitted through is multiplexed onto return arm ladder, spacing being such that interference between light from different prevented. The signals received by fiber receiver which couples interfering reference signal to produce phase difference representing conditions influencing selected sensors. Embodiments disclosed use either pulsed or continuous wave sources. another comprise plurality interferometers connected series configuration common fiber, provides output comprising receivers. Functional equivalents provide receivers birefringent two-mode fiber. path differences pair arms prevent various lengths structured so produces relating affecting transmission specific sensor. amplitude modulation technique providing heterodyned