132 results about "Reconfigurable optical add-drop multiplexer" patented technology

In today's reconfigurable optical add / drop multiplexer (ROADM) based optical node, transponders associated with the ROADMs' add / drop ports are dedicated to a given network node interface. Dedicated transponders reduce the flexibility to route around network failures. Example embodiments of the invention includes an optical node and corresponding method for routing optical signals within an optical node. The optical node may include at least two ROADMs to transmit respective wavelength division multiplexed (WDM) signals onto at least two inter-node network paths and at least one add / drop module including add ports to direct add wavelengths received from tributary network paths to each of the ROADMs via intra-node network paths to allow the wavelengths to be available to be added to the inter-node network paths. Advantageously, a transponder may transmit and receive to and from different network node interfaces within the optical node, thereby improving the optical node's ability to route around network failures.

A reconfigurable optical add / drop multiplexer (ROADM) includes a first optical dynamic gain equalization filter (DGEF) having a first input for receiving an initial wavelength division multiplexed (WDM) signal, a first output for sending a phase shifted WDM signal, and a second output connected to a demultiplexer for demultiplexing a WDM drop signal thereby producing a plurality of drop channels. A second DGEF having a first input for receiving the phase shifted WDM signal, a second input connected to a multiplexer, for multiplexing a plurality of add channels to produce thereby a wavelength division multiplexed (WDM) add signal, and an output for sending a second adjusted WDM signal. The ROADM allows for the channels from the initial WDM signal to be dropped, added and equalized.

A system and method for dynamically adding / dropping wavelengths in a reconfigurable optical add-drop multiplexer (ROADM) transport network to form a wave division multiplexing virtual private network is disclosed. The system includes at least one optical transponder, a plurality of optical fan-out devices, each arranged to receive an input signal from a network degree and coupled to at least one of a plurality of optical fan-in devices, each optical fan-in device arranged to output a signal to a network degree, the optical fan-out devices comprising at least one wavelength selective switch and the optical fan-in devices comprising at least one wavelength selective switch, the optical fan-out devices and optical fan-in devices being connected so as to enable signals input from each of the plurality of network degrees to be switched to another network degree of the plurality of network degrees; a plurality of demultiplexers for locally dropping selected wavelengths; a plurality of multiplexers for locally adding selected wavelengths; and at least one customer-dedicated fiber switch interposed between the at least one optical transponder and the plurality of demultiplexers and multiplexers. The fiber switch is coupled to wavelengths and degrees that are allocated for a bandwidth-on-demand application. Other configurations include additional fan-in and fan-out devices interposed between a mux / demux assembly and the optical transponders to support wavelength redistribution applications.

In today's reconfigurable optical add / drop multiplexer (ROADM) based optical node, ROADMs multiplex (and demultiplex) colored optical signals to form wavelength-division multiplexed (WDM) signals. Transponders connected to the ROADMs' add / drop ports convert noncolored optical signals to colored optical signals (and vice versa). Dedicating transponders to given ports degrades the node's ability to route around network failures. Example embodiments of the invention include an optical node and corresponding method for routing optical signals within an optical node that compensate for this inflexibility. The optical node may include two ROADMs to transmit respective WDM signals onto at least two internode network paths and a routing module that can direct channels of the same wavelength along different internode network paths. Advantageously, a transponder may transmit (receive) different signals at the same wavelength to (from) different network node interfaces within the optical node, thereby improving the optical node's ability to route around network failures.

A reconfigurable optical add drop multiplexer core device includes a light distributor, a light combiner, and first and second sets of add and drop ports. The light distributor is configured to receive an optical signal along a primary input of the reconfigurable optical add drop multiplexer core device and to distribute the received optical signal along a plurality of subtending outputs. The light combiner is configured to receive optical signals along a plurality of subtending inputs, to combine the received optical signals into a combined signal, and to output the combined signal. The add and drop ports in the first set function as add and drop ports, respectively, and the add and drop ports in the second set function as both add and drop ports, respectively, and as express ports connectable to another reconfigurable optical add drop multiplexer core device.

A wavelength selective switch architecture for ROADMs for switching the spectral channels of a multi-channel, multi-wavelength optical signal between input and output ports employs a biaxial MEMS port mirror array for optimal coupling efficiency and ITU grid alignment, an anamorphic beam expander for expanding input optical signals to create an elongated beam profile, a diffraction grating for spatially separating the spectral channels, an anamorphic focusing lens system, an array of biaxial elongated channel MEMS micromirrors, a built-in Optical Channel Monitor, and an electronic feedback control system. The bi-axial channel micromirrors are rotatable about one axis to switch spectral channels between ports, and are rotatable about an orthogonal axis to vary the coupling of the spectral channel to an output port and control attenuation of the spectral signal for complete blocking or for a predetermined power level. The architecture affords hitless switching, near notchless operation, ITU channel alignment, high passband, stability over a broad temperature range, and minimum insertion loss through the optimal optical coupling efficiency enabled by the feedback control system.

An optical node includes a reconfigurable optical add drop multiplexer (ROADM) core configured to transmit optical signals of multiple-wavelengths to and receive optical signals of multiple-wavelengths from another optical node via a network interface, and to add optical signals thereto and to drop optical signals therefrom. The node also includes two of a colorless optical add / drop device, a colored optical add / drop device, and a spur optical device configured to receive signals from the network interface and output the received signals from a spur interface, to add signals that are output from the spur interface without passing through the network interface, to receive signals from the spur interface and transmit the received signals to the ROADM core and the network interface, and to receive signals from the spur interface and drop the received signals without passing through the network interface.

The invention provides a unified optical network architecture for metro and access communication networks, wherein a metro ring network interfaces access PONs through one or more reconfigurable Optical Add / Drop Multiplexers to provide wavelength-reconfigurable all-optical transmission of communication signals from the metro ring network to designated optical network units associated with the end-users, and wherein one metro hub located in the metro ring network is utilized to set transmission wavelengths and timing for both downstream and upstream signal transmission for multiple access PONs.

An optical node includes a reconfigurable optical add drop multiplexer (ROADM) core configured to transmit optical signals of multiple wavelengths to and receive optical signals of multiple wavelengths from another optical node. The ROADM core is also configured to add optical signals thereto and to drop optical signals therefrom. The node also includes two different types of add-on devices, each connected to the ROADM core device and configured to process optical signals of multiple wavelengths. As a result, a multifunctional and reconfigurable optical node can be provided.

In today's reconfigurable optical add / drop multiplexer (ROADM) based optical node, transponders associated with the ROADMs' add / drop ports are dedicated to a given network node interface. Dedicated transponders reduce the flexibility to route around network failures. Example embodiments of the invention includes an optical node and corresponding method for routing optical signals within an optical node. The optical node may include at least two ROADMs to transmit respective wavelength division multiplexed (WDM) signals onto at least two inter-node network paths and at least one add / drop module including add ports to direct add wavelengths received from tributary network paths to each of the ROADMs via intra-node network paths to allow the wavelengths to be available to be added to the inter-node network paths. Advantageously, a transponder may transmit and receive to and from different network node interfaces within the optical node, thereby improving the optical node's ability to route around network failures.

In today's reconfigurable optical add / drop multiplexer (ROADM) based optical node, ROADMs multiplex (and demultiplex) colored optical signals to form wavelength-division multiplexed (WDM) signals. Transponders connected to the ROADMs' add / drop ports convert noncolored optical signals to colored optical signals (and vice versa). Dedicating transponders to given ports degrades the node's ability to route around network failures. Example embodiments of the invention include an optical node and corresponding method for routing optical signals within an optical node that compensate for this inflexibility. The optical node may include two ROADMs to transmit respective WDM signals onto at least two internode network paths and a routing module that can direct channels of the same wavelength along different internode network paths. Advantageously, a transponder may transmit (receive) different signals at the same wavelength to (from) different network node interfaces within the optical node, thereby improving the optical node's ability to route around network failures.

The present invention provides systems and methods to adaptively control amplifier target power to maintain signal launching power as per design in networks with wavelength selective switch (WSS)-based reconfigurable optical add-drop multiplexers (ROADMs) using micro-electromechanical system (MEMS). Accordingly, signal OSNR does not collapse faster for WSS-based ROADMs than other similar configured system without WSS-based ROADM. In order to correct amplifier target power, the present invention utilizes system information about side-lobe size and OSNR at each amplifier. Related information, such as ASE level and size of side-lobes at each channel from upstream amplifiers, is passed to the network controller at each amplifier. Meanwhile, with target signal level and local WSS attenuation setting (given side-lobe size vs. WSS attenuation known) of each channel, the amplifier calculates what is total output power should be and adaptively maintains that power.

The invention discloses a reconfigurable optical add-drop multiplexer (an ROADM structure) for realizing 16 channels with multiple orders. The ROADM structure comprises an input part, a first-order filtration area, a second-order filtration area, a local download area, a combiner and an output part which are connected through nanometer wire waveguides. The ROADM structure has a certain width by utilizing the free spectral width of a micro-ring resonator and filters a plurality of paths of incident wavelengths with respective orders so as to ensure that the wavelength number in each download waveguide is reduced progressively and finally realize the single wavelength download in each output port, thereby reducing the temperature control difficulty and improving the response speed of devices.

The present invention provides a directionless reconfigurable optical add / drop multiplexer (ROADM) system. The present invention provides a scalable all-optical switching element that includes a combination of 1×N wavelength selective switches (WSS), 1×N splitters / combiners, optical amplifiers, and tunable filters to provide a fully non-blocking solution which can be deployed in a scalable manner. The 1×N splitters are configured to split multiples copies of a plurality of drop wavelengths which can be amplified and sent to a tunable filter which selects out a particular wavelength for drop. The 1×N combiners are configured to combine multiple add wavelengths for egress transmission.