Patent ID: 6081368
Filing Date: 2000-06-27
Classification: H04B

Abstract:
An optical amplifier for amplifying two counter-propagating WDM optical signals in a bi-directional WDM optical communications system, each WDM signal comprised of plural optical signals of different wavelengths, said amplifier comprising:first and second bi-directional amplifier sections for amplifying multiple wavelength component signals passing therethrough in either direction, each said amplifier section comprising at least one optical circulator having at least three ports, two ports of which are connected to a respective pair of amplifier arms; anddisposed between said first and second amplifier sections a multiplexer section for separating signals from either one of said amplifiers into a plurality of wavelength components, passing them through unidirectional arms, and presenting the components in a recombined signal to the other of said amplifiers, whereby the effects of Rayleigh backscattering and amplified spontaneous emission are reduced.