Chromatic dispersion compensation in wavelength division multiplexed optical transmission systems

A dispersion compensator for use in a WDM optical communication system that includes a transmitter, receiver, and an optical fiber transmission path coupling said transmitter to said receiver, said transmission path including at least one optical amplifier, said dispersion compensator comprising:

• an optical splitter for dividing a signal introduced therein onto a plurality of optical paths, said signal having a prescribed bandwidth, said optical splitter being adapted to receive said signal from an intermediate point along said optical fiber transmission path;
• a bandpass filter disposed along each of said optical paths, said filters dividing the prescribed bandwidth of the signal into a plurality of distinct sub-bands;
• a dispersion compensating optical element coupled to each of the bandpass filters, said dispersion compensating optical elements each substantially compensating for dispersion at a prescribed wavelength within the bandpass of its respective bandpass filter;
• a coupler for recombining said distinct sub-bands, said coupler being adapted to couple said recombined distinct sub-bands onto said optical fiber transmission path.

A method for compensating for dispersion in a WDM optical communication system that includes a transmitter, receiver, and an optical fiber transmission path coupling said transmitter to said receiver, said method comprising the steps of:

• splitting a signal at an intermediate point along the transmission path to be directed onto a plurality of optical paths, said signal having a prescribed bandwidth;
• filtering the signals along each of said optical paths to divide the prescribed bandwidth of the signal into a plurality of distinct sub-bands;
• compensating for dispersion at a prescribed wavelength within the distinct sub-bands;
• recombining said distinct sub-bands and directing said recombined distinct sub-bands onto said optical fiber transmission path.

A WDM optical communications system, comprising:

• a transmitter and a receiver;
• an optical fiber transmission path coupling said transmitter to said receiver, said transmission path including at least one optical amplifier;
• a dispersion compensator disposed at an intermediate point along said transmission path, said compensator including:
• a wavelength routing device for dividing a signal having a prescribed bandwidth into a plurality of distinct sub-bands;
• a plurality of output paths for respectively receiving said plurality of distinct sub-bands;
• a dispersion compensating optical element coupled to each of the output paths, said dispersion compensating optical elements each substantially compensating for dispersion at a prescribed wavelength within the bandpass of its respective sub-band;
• a coupler for recombining said distinct sub-bands and coupling said recombined distinct sub-bands onto said optical fiber transmission path.

A WDM optical communication system, comprising:

• a transmitter and a receiver;
• an optical fiber transmission path coupling said transmitter to said receiver, said transmission path including at least one optical amplifier;
• a dispersion compensator disposed at an intermediate point along said transmission path, said compensator including:
• a circulator having at least an input port for receiving optical signals from the transmission path, an output port for transmitting optical signals onto the transmission path, and a third port;
• a wavelength routing device coupled to said third port of the circulator for dividing a signal having a prescribed bandwidth into a plurality of distinct sub-bands;
• a plurality of output paths for respectively receiving said plurality of distinct sub-bands;
• a dispersion compensating optical element coupled to each of the output paths, said dispersion compensating optical elements each substantially compensating for dispersion at a prescribed wavelength within the bandpass of its respective sub-band;
• a Faraday rotator mirror coupled to each of the dispersion compensating optical elements.

A dispersion compensator comprising:

• a plurality of optical paths configured to carry a wavelength division multiplexed optical signals having a prescribed bandwidth;
• a bandpass filter disposed along each of said optical paths, said filters dividing the prescribed bandwidth of the signal into a plurality of distinct sub-bands;
• and
• a dispersion compensating element coupled to each of said bandpass filters, said dispersion compensating optical elements each substantially compensating for dispersion at a prescribed wavelength within the bandpass of its respective bandpass filter.