A METHOD OF AMPLIFYING AN OPTICAL SIGNAL, AN OPTICAL AMPLIFIER FOR PERFORMING THE METHOD, AND USE OF SUCH AN OPTICAL AMPLIFIER AS A SOURCE OF LIGHT

摘要

An optical amplifier for signal light. The amplifier amplifies signals at a certain signal wavelength and consists of an active optical waveguide (4) of simple wave type geometry at the signal wavelength, a pump laser (2) for obtaining inverted population between the energy levels involved and coupling devices for coupling pump light and signal light in the active optical waveguide (4). The active optical waveguide is doped with ions of transition metals or metals from the groups of Lanthanides or Actinides. This doping is in a cylinder shell-shaped area (13) around the axis of symmetry of the waveguide (4) so that the reduction in the optical power originating from amplified spontaneous emission is greater than the reduction in the optical power originating from amplified signal light.