Fiber optic hydrophone design and submarine flank array architecture

A new fiber optic (FO) hydrophone, and an array configuration based on this new FO hydrophone suitable for submarine flank arrays is discussed. This FO hydrophone dimension is sufficiently large in size having the following significant features: 1) a planar hollow shape with curved side ends supporting smooth winding, and having a thin central metallic structure in the hollow shell, providing structural stability, leaving large cavity space on either side of the central structure, 2) easy component housing (delay coils, couplers, reflectors etc.) in the vacant cavity space, 3) single layer very long fiber winding, improving the acoustic sensitivity, 4) stiffening effect reduction of fiber on the mandrel, catering hydrophone with very long life, 5) a novel compact flank array realization only with hydrophones and fiber cable (all other components are accommodated inside the large hydrophone). The salient feature of this flank array is the accommodation of 64 sensors, on one wave length & one fiber cable, by using a suitable multiplexing scheme. An optimized configuration has arrived with 512 sensors connected to 8 wavelengths, 8 fibers and meets the submarine flank array requirements. The 512 sensor system is repeated on the other side of the submarine thus meeting a very large flank array compatible with the larger submarines.