Optical communications system having chromatic dispersion and polarization mode dispersion compensation

摘要

Described are an optical communications system and a method that allow for compensation of chromatic dispersion and polarization mode dispersion imparted to a communications signal propagating through an optical link. The system is based on a cost-effective optical transport architecture that accommodates baud rates exceeding 15 Gbaud and eliminates the need for costly optical dispersion compensators. Compensation for polarization mode dispersion is performed at the receiver using nonlinear processing. Advantageously, direct detection modulation using inexpensive electro-optic system components can be used in place of more costly and complex coherent and differential modulation formats. Digital filtering can be performed at the transmitter and the input signal can be inverted based on the nonlinearity of the transmitter electro-optic components. Consequently, the bandwidth and linearity requirements for the transmitter electro-optic components are relaxed, and cost reductions are realized.

主权项

1. A method for compensating for dispersion imparted to a communications signal propagating through an optical link in an optical communication system, the method comprising:
digitally processing an electrical input signal to be propagated through the optical link, according to a first compensation function, to generate a predistorted electrical signal, the first compensation function determined to mitigate chromatic dispersion imparted to the communications signal by the optical link; filtering the predistorted digital signal through a transmitter peaking filter; converting the predistorted electrical signal into a predistorted optical signal for transmission through the optical link after the filtering; generating a receiver electrical signal in response to a detection of the predistorted optical signal after propagation through the optical link; and digitally processing the receiver electrical signal according to a second compensation function to generate an output signal, the second compensation function determined to mitigate polarization mode dispersion, an extent of the mitigation of the polarization mode dispersion being dependent upon an extent to which the chromatic dispersion is mitigated, wherein the digitally processing the electrical input signal and the digitally processing the receiver electrical signal compensate for chromatic dispersion and polarization mode dispersion, respectively, at baud rates exceeding 15 Gbaud.