Abstract: A fiber transition segment for transitioning an optical fiber from a hydrophone module to the central axis of the module. The segment comprises a conical, elongated element and a cylindrical portion of reduced diameter that protrudes longitudinally from the wide end of the conical element. The cylindrical portion is reciprocally mounted within an interconnect spring at the end of the hydrophone assembly. The fiber transition segment has a helical internal groove for receiving the optical fiber from the interconnect spring. The groove is aligned with and approximately matches the pitch of the groove in the interconnect spring to provide a smooth transition to the fiber transition segment and then to the central axis of the module.

Abstract: A mount for use in an optical fiber hydrophone module to loosely secure hydrophone components while avoiding increasing noise to the hydrophone. A hydrophone core has a plurality of mandrels helically wrapped with optical fiber and connected along an axis. A cylindrical metal cage encircles the hydrophone core. Cloth tape is wrapped around and affixed to the metal cage. An open pore foam goes around the metal cage. Thermoplastic adhesive attaches the foam to the cloth tape. A cylindrical woven internal strength member goes around the foam, including two longitudinal positioning tapes. The positioning tapes are fastened to the member at each end, and the foam is between the positioning tapes. Thread is used to sew the positioning tapes to the foam at spaced intervals along the axis.

Abstract: A bypass cable assembly that protects bypass fibers from one end of a hydrophone assembly to the other, avoiding subjecting the fiber to excessive tow-induced drag loading or the loading incurred during handling of the module. The bypass cable assembly comprises an elastic woven fiber cable with a jacketed optical fiber attached to one side of the cable in a sinusoidal pattern. The cable is attached to a woven fiber protection assembly proximate at each end of the hydrophone assembly. Along a central portion of the cable, the cable transitions to be substantially parallel to the module central axis and is disposed alongside the hydrophone assembly. Elongation of the cable causes the period of the sinusoidal pattern to increase without imparting damaging stress to the optical fiber. The elastic woven fiber cable is periodically attached along the central portion of the cable to positioning tape of an internal strength member.

Abstract: An optical fiber splice protection apparatus that allows optical fiber to be spliced and placed in position on a mandrel in cases of assembling a module or repairing optical fiber that has been broken. The present invention comprises a splice protector affixed to a mandrel and a rotation sleeve for winding excess fiber onto the mandrel. The rotation sleeve is located between the splice protector and an adjacent mandrel. The rotation sleeve facilitates winding excess fiber onto the mandrel, and has a longitudinal axis aligned with the longitudinal axis of the hydrophone assembly with a groove to receive the fiber and maintain the fiber's minimum bend radius. The splice protector and the rotation sleeve are substantially semi-circular in cross-section. A method is also provided for protecting spliced optical fibers using a splice protector and rotation sleeve.

Abstract: A woven fiber protection cable assembly for use in an optical fiber hydrophone module. The assembly comprises an elastic woven fiber strap with at least one tube attached to one or more sides of the strap in a sinusoidal pattern. The strap at a first end and longitudinal middle portion is substantially aligned with the central axis of the hydrophone module. Two layers of the strap are fastened together in the longitudinal middle portion, and the first end of the strap comprises a loop. The two layers at the second end of the strap are spatially separated and on opposite sides overlap a fiber transition segment, around which one end of the tube is coiled. The elongation of the strap causes the period of the sinusoidal pattern to increase without imparting damaging stress to the optical fiber.

Abstract: A fiber splice tray for connecting optical fibers between hydrophone modules, allowing each module to be independently assembled. The tray houses the optical fiber in a small space envelope, and allows positioning of a spliced fiber along a straight portion of an internal groove. The internal groove has alternate paths for housing the fiber. The internal groove comprises two opposing parallel sections and two arcs at both ends of the parallel sections, making two continuous looped alternative fiber paths. The internal groove may further comprise two sections that are alternatives to the parallel sections and that cross each other in the middle of the tray. The various alternative fiber paths make it possible to position a splinted optical fiber splice or splice sleeve, which cannot tolerate a bend in the path, in a straight section of the groove.

Abstract: A termination assembly for use in an optical hydrophone module, comprising a module oil seal and an optical fiber seal. The termination assembly is used at the ends of modules and provides a means for filling individual modules with fill fluid. A module oil seal comprises a cylindrical wall defining a cavity, with one end substantially closed and the other end open. An annular face plate on the open end makes a seal dividing a coupling and a clevis. A check valve is mounted to an orifice that passes through the substantially closed end of the module oil seal. Optical fibers pass through the substantially closed end and the optical fiber seal is provided around the optical fiber that passes therethrough. The fiber seal fits snugly in a module oil seal opening. Both components serve to provide a seal that can withstand high pressures and maintain optical fiber integrity.

Abstract: A bypass cable assembly that protects bypass fibers from one end of a hydrophone assembly to the other, avoiding subjecting the fiber to excessive tow-induced drag loading or the loading incurred during handling of the module. The bypass cable assembly comprises an elastic woven fiber cable with a jacketed optical fiber attached to one side of the cable in a sinusoidal pattern. The cable is attached to a woven fiber protection assembly proximate at each end of the hydrophone assembly. Along a central portion of the cable, the cable transitions to be substantially parallel to the module central axis and is disposed alongside the hydrophone assembly. Elongation of the cable causes the period of the sinusoidal pattern to increase without imparting damaging stress to the optical fiber. The elastic woven fiber cable is periodically attached along the central portion of the cable to positioning tape of an internal strength member.

Abstract: A fiber splice tray for connecting optical fibers between hydrophone modules, allowing each module to be independently assembled. The tray houses the optical fiber in a small space envelope, and allows positioning of a spliced fiber along a straight portion of an internal groove. The internal groove has alternate paths for housing the fiber. The internal groove comprises two opposing parallel sections and two arcs at both ends of the parallel sections, making two continuous looped alternative fiber paths. The internal groove may further comprise two sections that are alternatives to the parallel sections and that cross each other in the middle of the tray. The various alternative fiber paths make it possible to position a splinted optical fiber splice or splice sleeve, which cannot tolerate a bend in the path, in a straight section of the groove.

Abstract: A termination assembly for use in an optical hydrophone module, comprising a module oil seal and an optical fiber seal. The termination assembly is used at the ends of modules and provides a means for filling individual modules with fill fluid. A module oil seal comprises a cylindrical wall defining a cavity, with one end substantially closed and the other end open. An annular face plate on the open end makes a seal dividing a coupling and a clevis. A check valve is mounted to an orifice that passes through the substantially closed end of the module oil seal. Optical fibers pass through the substantially closed end and the optical fiber seal is provided around the optical fiber that passes therethrough. The fiber seal fits snugly in a module oil seal opening. Both components serve to provide a seal that can withstand high pressures and maintain optical fiber integrity.

Abstract: An optical fiber splice protection apparatus that allows optical fiber to be spliced and placed in position on a mandrel in cases of assembling a module or repairing optical fiber that has been broken. The present invention comprises a splice protector affixed to a mandrel and a rotation sleeve for winding excess fiber onto the mandrel. The rotation sleeve is located between the splice protector and an adjacent mandrel. The rotation sleeve facilitates winding excess fiber onto the mandrel, and has a longitudinal axis aligned with the longitudinal axis of the hydrophone assembly with a groove to receive the fiber and maintain the fiber's minimum bend radius. The splice protector and the rotation sleeve are substantially semi-circular in cross-section. A method is also provided for protecting spliced optical fibers using a splice protector and rotation sleeve.

Abstract: A woven fiber protection cable assembly for use in an optical fiber hydrophone module. The assembly comprises an elastic woven fiber strap with at least one tube attached to one or more sides of the strap in a sinusoidal pattern. The strap at a first end and longitudinal middle portion is substantially aligned with the central axis of the hydrophone module. Two layers of the strap are fastened together in the longitudinal middle portion, and the first end of the strap comprises a loop. The two layers at the second end of the strap are spatially separated and on opposite sides overlap a fiber transition segment, around which one end of the tube is coiled. The elongation of the strap causes the period of the sinusoidal pattern to increase without imparting damaging stress to the optical fiber.

Abstract: A fiber transition segment for transitioning an optical fiber from a hydrophone module to the central axis of the module. The segment comprises a conical, elongated element and a cylindrical portion of reduced diameter that protrudes longitudinally from the wide end of the conical element. The cylindrical portion is reciprocally mounted within an interconnect spring at the end of the hydrophone assembly. The fiber transition segment has a helical internal groove for receiving the optical fiber from the interconnect spring. The groove is aligned with and approximately matches the pitch of the groove in the interconnect spring to provide a smooth transition to the fiber transition segment and then to the central axis of the module.