Reduction of ASE in WDM optical ring networks

摘要

The present invention provides a wavelength division multiplexed optical communication system including an optical fiber ring configured to carry at least one wavelength division multiplexed optical communication signal having plural optical channels at different wavelengths. Optical amplifiers are interposed along the optical fiber ring for optically amplifying the wavelength division multiplexed optical communication signal. Each optical amplifier produces amplified spontaneous emission as well as amplifying the optical channels of the WDM signal. At each amplifier, amplified spontaneous emission is selected by an optical feedback selector and is fed back to the optical amplifier input via an optical feedback path; the created wavelength travels along the ring and is dropped near the input of the next adjacent amplifier, reducing ASE in the optical fiber ring. Using this technique, closed-ring amplified WDM metropolitan networks can be formed without the need to “break the ring” in order to avoid uncontrolled build-up of ASE.