USA As Represented by Secretary of the Navy

Gerald E Holmberg

Roger L Morency

Jeffrey C Gremillion

Eugene L Green

An array through a first to a second side of a three-sided junction, accessed remotely by a single mode fiber transmits a light pulse sequence to the array and receives sound modulated return light signals via the second to a third side of the junction. Within each hydrophone, butt coupled fiber joints form a continuous structure, encapsulated within a compressible plastic tube for mechanical stability. Tube volume expands and contracts linearly with variations in acoustic pressure thereby proportionally modulating the optical path therethrough. Each joint is a partial reflector reflects part of the incident light beam back via the second to third side of the junction to a posthydrophone compensating interferometer which compensates for path difference between equally spaced array joints; From the third side of the junction the reflections from the butt coupled fiber joints pass through a light detector and signal processor. Interference is produced between reflected light beams from successive joint pairs, from which phase modulation due to each hydrophone may be obtained. The partially reflecting joints thus permit serial sampling of the phase modulation of light as a function of position. Light reflected from the fiber lead/array joint provides a signal that is proportional to light source intensity variations and perturbation effects of the lead which may be cancelled. Since the lead is a propagating medium for phase modulated light beams from all joints, lead-induced phase noise is not present. Since path differences between interferring beams is matched precisely by the compensating interferometer, light source phase noise is cancelled. In an important variation of the invention the compensating interferometer is located in the fiber through which the array is accessed, ahead of the three-sided optical junction. Pursuant to this variation of invention the parts of the incident light beam that are similarly reflected back from the joints and pass from the second to third sides of the junction, but there is no compensating interferometer in the path from the third side of the junction to the light detector and a signal processor.

Pulse sampled optical fiber hydrophone array (U)

A hydrodynamic cable deployment system suitable for deploying cable from a oil on a moving underwater vessel is disclosed. The present invention provides hydrodynamic assist means for cooperation with a system for the deployment of a cable tether used for communication between a marine vessel and an expendable or non-expendable device launched therefrom by providing means for generating hydrodynamic pressure to produce a current in the direction of cable deployment, assisting in the process of stripping the cable from the coil. The means for generating hydrodynamic pressure can be implemented via a pump, or via a water intake scoop which utilizes the forward movement of the marine vessel to force water therethrough. Additional pressure can be induced and concentrated in a predetermined direction through directional nozzles. Further hydrodynamic assistance can be provided by inserting interspaced diameter constrictions within the inside diameter of a hose through which the cable is deployed, thereby providing periodic increases in the water velocity along the direction of travel of the cable.

Hydrodynamic cable deployment system

An armored fiber optic cable is disclosed having both fiber optics and ar wires located outside the cable core in position where the fiber optics experience low strain when the cable is under stress. In one embodiment, metal armor wires and optical fibers embedded in metal tubes are arrayed in one or more layers about and outside the cable core. In another embodiment, KEVLAR armor wires and optical fibers embedded within a hard composite shell are arrayed in one or more layers about and outside the cable core, and a layer of KEVLAR armor is provided surrounding the one or more layers. In each of the embodiments the strains that the fiber optics experience due to core stresses and due to core residual strain is materially reduced over the heretofore known armored fiber optic cables.

Armored fiber optic cables

A fiber optic cable connection for high pressure environments utilizes a er optic cable having (i) a multiplicity of fiber optic strands extending axially therein, (ii) a strength member extending axially in spaced relationship thereabout, (iii) an outer jacket, and (iv) a filler matrix within the strength member and in which the strands are encased, a precision connector with an inner face having an axially extending recess and with axially extending passages extending from the transverse wall of the recess to the outer face of the connector member and through which the fiber optic strands extend. A preload insert member is disposed about the strands with its outer end extending into the recess of the connector and a peripheral shoulder abutting the inner face of the connector member. The strength member of the cable is disposed about extending the reduced diameter portion of the insert member. A body member is disposed about the insert member and has its outer end extending over the inner end portion of the connector. A nut threadably engaged on the inner end portion of the insert member and abutting the inner end of the body member is tightened on the insert member against the body member to tension the insert member above a predetermined value. A relatively rigid resin filler is provided in the insert member about the strands connector member, and a relatively compressible filler in the inner end of the insert member, and a sealing boot extending about the cable jacket over the strength member and nut and onto the body member.

High pressure fiber optic connector plug

Methods are disclosed for forming precision, fiber optic interfaces, and a recision, fiber optic interface is disclosed in accordance therewith, an electroformed disk is disclosed to provide fiber alignment, and electrical discharge machining (EDM) is disclosed to provide accurate angular alignment of optical fibers at a planar optical interface. In one method embodiment, a combination of EDM, an alignment bushing and an electroformed disk are used to fashion a precision multi-channel fiber optic interface, and in one interface and method embodiment, two electroformed disks are used to provide a precision, multi-channel fiber optic interface.

Growing community of inventors

Quaker Hill, CT, United States of America

Gerald E Holmberg