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dc.contributor.authorGardner, D.L.
dc.contributor.authorHofler, T.
dc.contributor.authorBaker, S.R.
dc.contributor.authorYarber, R.K.
dc.contributor.authorGarrett, S.L.
dc.date.accessioned2014-12-08T23:02:45Z
dc.date.available2014-12-08T23:02:45Z
dc.date.issued1987-07
dc.identifier.citationJournal of Lightwave Technology, Volume LT-5, No. 7, July 1987
dc.identifier.urihttp://hdl.handle.net/10945/44062
dc.description.abstractA fiber-optic interferometric sensor has been developed which consists of a seismic mass of 520 gm supported by two rubber mandrels, each wound with a single layer of single-mode optical fiber 6.5 m long. One end of each fiber is cleaved to enhance reflection. The other ends are interconnected via a fiber-to-fiber 3-dB coupler, forming a Michelson interferometer. When the case of the sensor is displaced, the fiber around one mandrel extends in length while the other contracts. The resulting â push-pullâ mechanical operation of the sensor allows both legs of the interferometer to be active, providing good common mode rejection of spurious effects, as a reference leg is not required. This, together with the fact that the light traverses each leg of a Michelson interferometer twice due to reflection, provides the sensor with four times the sensitivity of a conventionally constructed interferometric sensor. sensitivities of 8500 rad of optical phase shift per micrometer of case displacement have been measured above the massspring resonance, where the sensor operates as a seismometer. Below resonance the sensor operates as an accelerometer with a measured sensitivity of 10 500 rad/g, the highest reported to date. Including both thermodynamic and demodulator noise sources, below resonance the sensor has a detection threshold of l ng/JHz, a 20- dB improvement over the best existing conventional noise vibration sensors.en_US
dc.rightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. As such, it is in the public domain, and under the provisions of Title 17, United States Code, Section 105, may not be copyrighted.en_US
dc.titleA Fiber-optic Interferometric Seismometeren_US
dc.typeArticleen_US


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