A power tether for aerial devices such as balloons or drones operates with as few as a single conductor, providing a ground return by capacitive coupling between the aerial device and a ground plane at a base station. High-frequency, high-voltage power allows significant power transfer through the low capacitance between the aerial station and the ground minimizing the necessary current flow.

A power tether for aerial devices such as balloons or drones operates with as few as a single conductor, providing a ground return by capacitive coupling between the aerial device and a ground plane at a base station. High-frequency, high-voltage power allows significant power transfer through the low capacitance between the aerial station and the ground minimizing the necessary current flow.

This structure includes a transparent member. The transparent member has a first surface and a second surface arranged to face each other, and allows light entering from the first surface to propagate toward the second surface by reflection. The transparent member has a plurality of slopes inclined with respect to the first surface, in an optical path between the first surface and the second surface.

This structure includes a transparent member. The transparent member has a first surface and a second surface arranged to face each other, and allows light entering from the first surface to propagate toward the second surface by reflection. The transparent member has a plurality of slopes inclined with respect to the first surface, in an optical path between the first surface and the second surface.

A stretchable cable is provided that allows an extra length to be reduced when routed in a movable part. The stretchable cable includes an elastically deformable hollow insulation having a hollow portion that is continuous along a cable longitudinal direction, and at least one electricity- or light-conducting wire-shaped body provided in a spiral shape along the cable longitudinal direction and fixed to the hollow insulation to stretch and contract together with the hollow insulation. The cable is elongated not less than 1.2 times when a tensile force is applied, and the cable returns to an original length when the tensile force is removed.

An optical connector cable including an optical cable, a first resin member, and a second resin member is disclosed. The optical cable includes a plurality of optical fibers and a sheath surrounding the plurality of optical fibers. End portions of the plurality of optical fibers extend to the outside from an end surface of the sheath. The first resin member holds the end portions of the plurality of optical fibers extending to the outside from the end surface of the sheath. The second resin member covers at least a part of the first resin member and an end portion of the sheath.

A downhole cable includes a central core. The central core includes a metal tube having a plurality of optical fibers therein or a copper wire. The downhole cable further includes an extruded aluminum tube surrounding the central core.

A cable comprising: a plurality of optical fiber cores; and one or more optical fiber core wires including one or more of the optical fiber cores. Further, at least one of the optical fiber core wire is fixed at a plurality of positions in a longitudinal direction of the cable so as to achieve substantially no displacement in a cable radial direction, at least a pair of the optical fiber core wires are fixed in a plane perpendicular to the longitudinal direction of the cable so as to achieve substantially no displacement relative to each other, and sensing of a strain profile in the longitudinal direction of at least the pair of the optical fiber core wires leads to achievement of sensing of a shape of the cable in the longitudinal direction.

This optical fiber cable is a central-core-type cable in which slotted rods are not used, and is composed of a core, a wrapper, a tension member, a ripcord, a sheath, and the like. The core is formed by twisting together a plurality of optical fiber units without back-twisting. The optical fiber units are formed by twisting together a plurality of intermittently-fixed optical fiber ribbons. A direction in which the optical fiber ribbons are twisted together is same as a direction in which the optical fiber units are twisted together.

Disclosed are an electrical penetration assembly, a manufacturing method thereof, and an electrical penetration device, which relate to the technical field of electrical penetration. The electrical penetration assembly comprises sealing glass (5), an outer tube (4) and a conductor (7) inserted into the outer tube (4), wherein both ends of the outer tube (4) are blocked by supporting and fixing blocks (8), and both ends of the conductor (7) respectively protrude from the corresponding supporting and fixing blocks (8); the sealing glass (5) is sintered between the conductor (7) and the outer tube (4) and is configured to divide an annular cavity jointly enclosed by the conductor (7), the outer tube (4) and the supporting and fixing blocks (8) into an upper cavity and a lower cavity; an optical fiber (14) penetrates the sealing glass (5), at least one end of the optical fiber (14) is connected to an optical fiber splice (3) after protruding from the corresponding supporting and fixing block (8), and a portion of the optical fiber (14) located in the sealing glass (5) is inscribed with a fiber Bragg grating to form a first fiber Bragg grating sensor (1). By utilizing the first fiber Bragg grating sensor (1) to monitor the strain and temperature of the sealing glass (5) in real time, not only can it judge whether the electrical penetration assembly meets the requirements for hermeticity, but also enable precise control of the sintering temperature.