Radiation power equalizer

Abstract

The invention provides a radiation power equalizer for an optical communication system, the equalizer characterized in that it includes: (a) an optical demultiplexer ( ) for partitioning information-bearing radiation received at the equalizer into one or more radiation components corresponding to wavelength division multiplexed communication channels of the system; (b) a liquid crystal cell array ( ) for selectively transmitting or attenuating said one or more radiation components; (c) an optical multiplexer ( ) for combining one or more of the radiation components transmitted or attenuated through the cell array ( ) to provide combined radiation; (d) a transmitter erbium-doped fiber amplifier ( ) coupled to a PIN diode detector array ( ) for measuring radiation power present in said one or more of the radiation components included in the combined radiation and generating one or more corresponding component radiation power indicative signals; and (e) a control module ( ) for receiving said one or more power indicative signals from the array ( ) and controlling attenuation provided by the cell array ( ) so that the radiation components included in the combined radiation are substantially of mutually similar radiation power. Action of the cell array ( ) ensures that radiation components present in the combined radiation are mutually power matched, thereby assisting to alleviate power hogging by radiation components having relatively greater radiation power in devices such as erbium-doped fiber amplifiers (EDFAs).