| 摘要 |
A fiber optic interferometric hydrophone is based on the change in optic path length of optic fibers bonded to both sides of a bending beam which acts as an acoustically sensitive diaphragm. The bending beam is segmented into an even number of segments, acoustic windows are arranged such that opposite sides of the beam see the acoustic field in adjacent segments, and the optic fibers cross from one side of the beam to the other to maintain the phase of strain signal for the two fibers, one on each side, along the full length of the bending beam. The fringe sensitivity of the interferometer is multiplied by two since both interferometer legs are strained by the acoustic field, and of opposite sign, and further multiplied by the number of segments compared to a single simple beam bender of the dimensions of one segment. This configuraion has the further advantages of cancelling out lateral acceleration noise, and of providing a larger transducer for integrating low level sounds, both of which improve the signal-to-noise level. The small lateral dimensions of such a hydrophone are advantageous in towed arrays. Ancillary equipment such as light source, and detectors, and mechanical packaging for various purposes, are well known in the art.
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