Ciena Corporation

Yunfeng Shen

Shan Zhong

Harshad P Sardesai

Charles Haggans

Xiumin Liu

The present disclosure includes a configuration of a polarization control system and an algorithm that realize fast polarization controlling and tracking while avoiding the Glitch problems (i.e., loss of polarization tracking). The polarization controller includes multiple stages along with tunable orientation and retardation angles. The retardation angles are initialized to at least two different values for better polarization tracking in normal mode. In a normal mode, only the orientation angles of the polarization controller are dithered. When the monitored error is higher than the threshold, the polarization controller enters a glitch mode, and Glitch detection can be improved through error signal data processing. In the Glitch mode, at least one retardation angle is dithered along with the orientation angles. After the Glitch problem is avoided, the polarization controller stops dither the retardation angles and move all wave plates back to their initial values, and the polarization controller enters the normal mode.

Polarization control systems and methods with endless polarization tracking using a dithering algorithm

The present disclosure provides polarization mode dispersion compensation (PMDC) and polarization de-multiplexing systems and methods for polarization multiplexed (PolMux) optical transmission systems. The PMDC detects an error signal before a polarization splitter in PolMux systems for controlling polarization controllers (PC) and/or DGDs in the PMDC for return-to-zero (RZ) differential m-phase shift keying (DmPSK) signals. For bit-aligned PolMux systems, the error signal could be the level of clock frequency at one, two, or more times of the baud rate at one polarization. For bit-interleaved PolMux systems, the error signal could be the level of clock frequency at two times of the baud rate at one polarization. The PMDC can operate in PolMux systems with any arbitrary time offset between the two polarizations. The polarization de-multiplexer utilizes error detection at both output arms of a polarization splitter to mitigate PDL impact on any PolMux type of signal.

Polarization mode dispersion compensation and polarization demultiplexing systems and methods for optical transmission systems

An optical communication device, and related method, are provided for providing a tailored, spectrally non-uniform gain over a broad spectrum. In particular, the optical communication device includes an optical amplifier having a dynamic gain equalization (DGE) circuit that adjusts the gain spectrum of the optical amplifier to provide uniform gain, at a desired level, within individual channel bands in accordance with the data rates of channels in those bands. Accordingly, the overall spectrum has a 'stepped' profile with higher gain values for high data rate channels and lower gain values for lower rate channels. As a result, a WDM system can accommodate multiple data rate signals by providing spectrally uniform high gain for high data rate channels, and low gain for lower rate channels. Improved signal quality can thus be achieved for both high speed and low speed signals in a single WDM system.

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Bethesda, MD, United States of America

Yunfeng Shen