摘要 |
A folded Sagnac fiber optic sensor array uses a common delay path to reduce distributed pickup in downlead fibers. The sensor array is used to detect perturbations (eg., acoustic waves in water). By basing the folded Sagnac sensor array on operating principles similar to the Sagnac interferometer th e sensor array has a stable bias point, has a reduced phase noise, and allows a broadband signal source to be used rather than requiring a more expensive narrowline laser. A large number of sensors can be multiplexed into the architecture of the sensor array. In one particularly preferred embodiment, the sensor array is configured with couplers (2024) and amplifiers (2022) selected to direct substantially equal portions of an input light signal to each sensor array. In another particularly preferred embodiment, first and second delay paths are provided for light at first and second wavelengths (2210 & 2212) to increase the dynamic range of the sensors.
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