Abstract: A method for producing a prestressed fiber-optic sensor of two superposed metal strips (2,3) sheathing an optical fiber (1) with the strips being secured to each other along their lateral sides to provide a sheath exerting a prestress on the optical fiber includes a first step of superposing the lateral sides of the strips and aligning the edges of the strips. The superposition of the sides is carried out so as to produce a desired prestress on the optical fiber after the sides have been secured together. In a further step, the strips are continuously welded to each other to unite the adjacent edges after superposition of their lateral sides. The welding is performed simultaneously along both sides of the strips and with the same input of energy. The invention also relates to apparatus for carrying out the method and a prestressed fiber-optic sensor produced thereby.

Abstract: Optical fiber suitable for use in optical time domain reflectometry and method of manufacturing the fiber. The method of manufacturing the optical fiber suitable for use in optical time domain reflectometry includes, during drawing of the fiber (2), a thin continuous coating is deposited on the fiber. A part of the coating is thereafter removably ablated in the form of a helix (15) coaxial with the fiber by rotating a laser beam (17) in a plane orthogonal to the axis simultaneously with axial movement of the fiber.