Optical communication system having dynamic gain equalization

An optical communication device, comprising:na dynamic gain equalization circuit coupled to an optical communication path, said optical communication path being configured to carry a plurality of optical signals, each of which being at a respective one of a plurality of wavelengths, said dynamic gain equalization circuit having an adjustable, wavelength dependent transmission spectrum, at least a portion of said transmission spectrum having a substantially non-uniform slope;an optical amplifier coupled to said optical communication path, and being configured to impart optical amplification to said plurality of wavelengths; andan optical performance monitoring circuit coupled to said optical communication path, said optical performance monitoring circuit being configured to sense said plurality of optical signals and generate a sense signal in response thereto, said transmission spectrum being adjusted in response to said sense signal.

An optical communication system, comprising:na plurality of optical signal emitters, each of which outputting a respective one of a plurality of optical signals, each of said plurality of optical signals being at a respective one of a plurality of wavelengths;an optical combiner having a plurality inputs and an output, each of said plurality of inputs being coupled to a respective one of said plurality of optical signal emitters, said optical combiner being configured to supply said plurality of optical signals onto an optical communication path coupled to said output of said combiner;a first group of optical amplifiers coupled to a first section of said optical communication path;a second group of optical amplifiers coupled to a second section of said optical communication path;a first dynamic gain equalization circuit coupled to said first section of said optical communication path, said first dynamic gain equalization circuit having a first adjustable, wavelength dependent transmission spectrum, at least a portion of said transmission spectrum having a substantially non-uniform slope;a second dynamic gain equalization circuit coupled to said second section of said optical communication path, said second dynamic gain equalization circuit having a second adjustable, wavelength dependent transmission spectrum, at least a portion of said transmission spectrum having a substantially non-uniform slope;a first optical performance monitoring circuit coupled to said first section of said optical communication path, said first optical performance monitoring circuit being configured to sense said plurality of optical signals and generate a first sense signal in response thereto, said first transmission spectrum being adjusted in response to said sense signal; anda second optical performance monitoring circuit coupled to said second section of said optical communication path, said second optical performance monitoring circuit being configured to sense said plurality of optical signals and generate a second sense signal in response thereto, said second transmission spectrum being adjusted in response to said sense signal.

An optical communication method, comprising:nmeasuring a spectrum associated with a wavelength division multiplexed (WDM) signal comprised of a plurality of optical signals carried on an optical communication path, each of said optical signals being at a respective one of a plurality of wavelengths;determining a difference between said measured spectrum and a predetermined spectrum with respect to a parameter associated with said plurality of optical signals; andperforming dynamic gain equalization on the WDM signal by adjusting a power associated with each of said plurality of optical signals in response to said difference,wherein said measuring step is a first measuring step in connection with said plurality of optical signals carried by a first section of said optical communication path, said method further comprising:performing a second measuring step to measure a spectrum associated with a plurality of optical signals carried by a second section of said optical communication path, said first section being upstream from second section relative to a direction of propagation of said plurality of optical signals in said optical communication path; anddisabling said measuring at said second section during said step of adjusting.

An optical communication method, comprising the steps of:nmonitoring a plurality of optical signals propagating on an optical communication path, each of said plurality of optical signals being at a respective one of a plurality of wavelengths, said first monitoring occurring at a first location along said optical communication path;further monitoring said plurality of optical signals at a second location along said optical communication path remote from said first location;detecting the presence of variation in power levels associated with said plurality of optical signals at said first and second locations in response to said monitoring and further monitoring, respectively;adjusting said power levels at a third location along said optical communication path remote from said first and second locations to thereby offset at least a portion of said variation in said power levels; andfurther adjusting said power levels at a fourth location along said optical communication path, said fourth location being remote from said first, second and third locations.

An optical communication method in accordance with 31, wherein said adjusting step further includes non-uniformly adjusting said power levels in accordance with said plurality of wavelengths.

An optical communication device, comprising:na dynamic gain equalization circuit coupled to an optical communication path, said optical communication path being configured to carry a plurality of optical signals, each of which being at a respective one of a plurality of wavelengths, said dynamic gain equalization circuit having an adjustable, wavelength dependent transmission spectrum, at least a portion of said transmission spectrum having a substantially non-uniform slope;an optical amplifier coupled to said optical communication path, and being configured to impart optical amplification to said plurality of wavelengths,said dynamic gain equalization circuit adjusting said transmission spectrum to attenuate wavelengths not populated by information-carrying channels to thereby attenuate amplified spontaneous emission (ASE) light carried by said optical communication path.

An optical communication device, comprising:na plurality of optical amplifiers coupled in series to an optical communication path, a first one of said plurality of optical amplifiers being positioned nearer a first end portion of said optical communication path than other ones of said plurality of optical amplifiers and a second one of said plurality of optical amplifiers, and said second one of said plurality of optical amplifiers being positioned nearer a second end portion of said optical communication path than said other ones of said plurality of optical amplifiers and said first one of said plurality of optical amplifiers; anda dynamic gain equalization circuit coupled to a third one of said plurality of optical amplifiers, said third one of said plurality of optical amplifiers being disposed along said optical communication path between said first and second ones of said plurality of optical amplifierswherein each of said optical amplifiers is a multi-stage optical amplifier.

An optical communication device, comprising:nfirst, second and third optical amplifiers coupled to an optical communication path, said first optical amplifier being located nearer a first end portion of said optical communication path than said second and third optical amplifiers, said second optical amplifier being located nearer a second end portion of said optical communication path than said first and third optical amplifiers, and said third optical amplifier being located between said first and second optical amplifier; anda dynamic gain equalization circuit coupled to said third optical amplifier,wherein each said first, second, and third optical amplifiers is a multi-stage optical amplifier.