Abstract: An optical-waveguide cable which is distinguished by a dispersion that avoids non-linearities in conjunction with a relatively low attenuation comprises at least one first section (a), which has fibers of a first type (H) which are designed as high-level fiber, and at least one second section (b), which has fibers of a second type (N) which are designed as low-level fiber, the fibers of the first type (H) being connected to the fibers of the second type (N) at at least one transition point (U) between the first and second sections (a, b), and the fibers of the first type (H) having a larger mode field diameter and a higher dispersion than the fibers of the second type (N).

Abstract: The main steps of the invention comprise feeding a sample signal (SOTDR) into the transmission line or path (2) using a multiplexer (8) during a current signal transmission and measuring the intensity of said sample signal (SOTDR), which is also coupled out via the multiplexer (80 and is reflected partially at faulty or error points. Part of the signal to be transmitted (Sin) can also be deviated by means of a coupling device (4) and the intensity of this proportion of the signal (Sup) can be compared with a threshold value. By evaluating the intensities that are measured, it is possible to detect and localize defects in the transmission path (2) or judge the quality of the transmission path (2 without interrupting the transmission.

Abstract: An optical-waveguide cable which is distinguished by a dispersion that avoids non-linearities in conjunction with a relatively low attenuation comprises at least one first section (a), which has fibers of a first type (H) which are designed as high-level fiber, and at least one second section (b), which has fibers of a second type (N) which are designed as low-level fiber, the fibers of the first type (H) being connected to the fibers of the second type (N) at at least one transition point (U) between the first and second sections (a, b), and the fibers of the first type (H) having a larger mode field diameter and a higher dispersion than the fibers of the second type (N).

Abstract: The invention describes an optical waveguide and a fiberoptic isolator wherein the optical waveguide rotating the plane of polarization of coupled light consists of a fiber core (11) exhibiting the Faraday effect, a fiber cladding (3) and a coating (5) concentrically surrounding the YIG-doped fiber core (11) and generating a permanent magnetic field. The outer coating (5) is manufactured from a material that is magnetizable or has magnetic properties, and the outer coating (5) is subdivided into two half-shells whose magnetic orientations are mutually opposed.