Abstract: An iterative process is used to set the phase prechirp of a WDM optical transport system to a system's optimal level that maximizes the signal quality. A signal degradation factor takes into account linear and non-linear effects along the optical path and is used as a receive end feedback signal to control the phase prechirp level at the transmitter site. By using the FEC corrected errors rate as the feedback signal, optimization of signal quality is performed even when the system is running error free. By using an adaptive phase prechirp transmitter, signal degradation compensation can be also performed on a per wavelength basis to compensate for the residual dispersion slope and to allow optimization of individual channels independently of the net link dispersion value.

Abstract: In accordance with the present invention, an improved method is provided for synchronizing a pulse stream with a data stream in an optical communications system. The improved method includes: generating an optical data signal for transmission through the optical communication system, where the data stream exhibits a duty cycle less than fifty percent and the optical data signal is formed from the pulse stream and the data stream; detecting an optical power level associated with the optical data signal; and synchronizing the pulse stream with the data stream based on the optical power level associated with the optical data signal. Specifically, the pulse stream is temporally aligned with the data stream when the average power of the optical data signal is maximized.

Abstract: An adaptive method is provided for applying chirp to an optical signal traversing through an optical network. The adaptive method comprises: applying chirp to an optical data signal at a transmitter in the optical network; transmitting the optical data signal through the optical network, the optical data signal having error detection data embedded therein; determining an error rate for the optical data signal at an egress point of the optical network, where the error rate is based on the error detection data embedded in the optical data signal; transmitting the error rate for the optical data signal to the transmitter; and adjusting the chirp being applied to the optical data signal at the transmitter based on the error rate for the optical data signal.

Abstract: In accordance with the present invention, an improved method is provided for synchronizing a pulse stream with a data stream in an optical communications system. The improved method includes: generating an optical data signal for transmission through the optical communication system, where the data stream exhibits a duty cycle less than fifty percent and the optical data signal is formed from the pulse stream and the data stream; detecting an optical power level associated with the optical data signal; and synchronizing the pulse stream with the data stream based on the optical power level associated with the optical data signal. Specifically, the pulse stream is temporally aligned with the data stream when the average power of the optical data signal is maximized.

Abstract: An adaptive method is provided for applying chirp to an optical signal traversing through an optical network. The adaptive method comprises: applying chirp to an optical data signal at a transmitter in the optical network; transmitting the optical data signal through the optical network, the optical data signal having error detection data embedded therein; determining an error rate for the optical data signal at an egress point of the optical network, where the error rate is based on the error detection data embedded in the optical data signal; transmitting the error rate for the optical data signal to the transmitter; and adjusting the chirp being applied to the optical data signal at the transmitter based on the error rate for the optical data signal.

Abstract: An iterative process is used to set the phase prechirp of a WDM optical transport system to a system's optimal level that maximizes the signal quality. A signal degradation factor takes into account linear and non-linear effects along the optical path and is used as a receive end feedback signal to control the phase prechirp level at the transmitter site. By using the FEC corrected errors rate as the feedback signal, optimization of signal quality is performed even when the system is running error free. By using an adaptive phase prechirp transmitter, signal degradation compensation can be also performed on a per wavelength basis to compensate for the residual dispersion slope and to allow optimization of individual channels independently of the net link dispersion value.