Optical amplifier for optical transmission system

摘要

The optical amplifier has an active waveguide (1) for amplifying the received optical signal, with a coupler (2). There is a pumping light source (3) for supplying energy to the active waveguide. An optical attenuation element (4) is placed in front or after the active waveguide, in the propagation direction of the optical signals. This exhibits a wavelength-dependent non-linear absorption characteristic. The attenuation element may be provided by a waveguide doped with the same rare earth element as the active waveguide. The optical attenuator may be applied along the length of the optical waveguide.