Ciena Corporation

Shan Zhong

Jean-Luc Archambault

Charles Haggans

Jun Bao

Yunfeng Shen

Vladimir Pelekhaty

Harshad P Sardesai

Xiaohui Yang

Mark Childers

Xiumin Liu

The present disclosure provides optimized configurations for a directionless reconfigurable optical add/drop multiplexer application. The present invention includes an add module with improved optical signal-to-noise through placing amplifiers prior to a multi-cast optical switch. The present invention includes various drop module configurations utilizing distributed gain, channel selective filters, and bi-directional configurations to reduce power consumption and complexity. Additionally, the present invention includes an integrated broadcast and select architecture.

Optimized directionless optical add/drop module systems and methods

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

The present invention provides a performance optimized receiver with a bandwidth adaptive optical filter for high speed long haul wavelength division multiplexed systems, such as 40 Gb/s and 100 Gb/s wavelength division multiplexed systems. The performance optimized receiver includes: a bandwidth and wavelength tunable optical filter, wherein the bandwidth and wavelength tunable optical filter is operable for receiving a plurality of wavelengths associated with a wavelength division multiplexed signal and passing one or more selected wavelengths, and wherein the bandwidth and wavelength tunable optical filter is operable for adjusting the bandwidth of each of the one or more selected wavelengths; and a receiver coupled to the bandwidth and wavelength tunable optical filter. Preferably, the receiver includes one or more of a bit error rate monitoring module and a signal quality monitoring module operable for monitoring the one or more selected wavelengths and providing feedback to the bandwidth and wavelength tunable optical filter such that the bandwidth and wavelength tunable optical filter adaptively adjusts the bandwidth of each of the one or more selected wavelengths.

Performance optimized receiver with bandwidth adaptive optical filter for high speed long haul WDM systems

The present invention provides a signal distribution module for use in a directionless reconfigurable optical add/drop multiplexer application, including: a multi-cast switch having a plurality of input ports and a plurality of output ports; a plurality of optical amplifiers coupled to the plurality of input ports of the multi-cast switch, wherein the plurality of optical amplifiers form an optical amplifier array; a tunable optical splitter coupled to the plurality of optical amplifiers; and a pump laser coupled to the tunable optical splitter.

Signal distribution module for a directionless reconfigurable optical add/drop multiplexer

The technology described herein provides a low-cost three-port reconfigurable optical add-drop multiplexer (ROADM) with an improved edge profile and add/drop flexibility. The technology described herein further provides a tunable spectral filter utilizing two sets of gratings and lenses and a two-axis micro-electro-mechanical system (MEMS) mirror with a selectively shaped cut-out disposed within the middle of the collimated optical path.

Systems and methods for providing a three-port reconfigurable optical add-drop multiplexer with an improved edge profile and add/drop flexibility

Consistent with the present invention, tunable demultiplexers are provided in WSS-based add/drop multiplexer. The tunable demultiplexers are modular and thus allow the add/drop multiplexer to be readily expandable, and facilitate flexible add/drop capabilities whereby a channel present on any input line to the WSS can be dropped and supplied to one or more desired outputs of the tunable demultiplexer. Similar flexibility can be achieved on the add-side of the WSS. Moreover, the demultiplexers and the WSS are remotely configurable, thus obviating the need to manually disconnect and connect demultiplexers to a router. In a particular embodiment, multicast switches are provided that permit the same channel, for example, to be provided to one or more outputs of the add/drop multiplexer, such that copy of the channel can carry working traffic while the other copy carries protection traffic. As a result, 1+1 and 1:N optical layer protection can be achieved.

Modular add/drop multiplexer including a wavelength selective switch

A universal in-service monitoring scheme to monitor performances of optical networks, including elements that make up the optical network, is proposed. The elements may be a wavelength selective switch or an optical cross connect. In this scheme, a small tunable probe signal is injected into the optical network via an input of the network. An output signal is received at the output and processed to determine if the probe signal is contained within the output signal. The scheme is such that probe signal injection and detection devices need not be physically co-located. Thus, the scheme is useful to test even optical network that spans thousands of miles. The probe signal is non-interfering with the network traffic so the network can be providing service while its performance is monitored. As examples of the probe signal detection mechanisms include lock-in amplification and coherent detection.

Switching status and performance monitoring technology for wavelength selective switch and optical networks

A flexible wavelength switch fabric may be implemented with multiple groups of reconfigurable blocking filters or with multiple multi-in, single out wavelength selective switches. The behaviors of reconfigurable blocking filters are individually settable, such as channel blocking, channel spacing, transmission rate, and default blocking state. Add and drop taps may be added to provide arbitrary add/drop capability. Optical splitters/combiners used may be tunable so that insertion losses may be minimized for the overall network.

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Ellicott City, MD, United States of America

Shan Zhong