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

A reconfigurable optical add-drop multiplexer is disclosed including an optical splitter receiving an input optical signal and splitting the input optical signal into a dropped optical signal and an express optical signal; a wavelength blocker optically coupled to the optical splitter, the wavelength blocker blocking particular wavelengths in the express optical signal; a cassette having a plurality of slots capable of accepting a plurality of pluggable optical filters; at least one pluggable optical filter optically coupled to the optical splitter, the pluggable optical filter filtering wavelengths so as to output a particular wavelength channel from the dropped optical signal; and an optical combiner optically coupled to the wavelength blocker and to an optical add path on which an optical add signal may be carried, the optical combiner combining the express optical signal having particular wavelengths expressed by the wavelength blocker and the optical add signal.

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.

A system and methods are disclosed for a hybrid silicon-organic scalable reconfigurable optical add-drop multiplexer. An embodiment of a scalable reconfigurable optical add-drop multiplexer (ROADM) includes an optical bus for optical signals of different wavelengths, a plurality of add/drop optical waveguides, and a plurality of ring resonators, each being optically coupled to the optical bus and to one of the add/drop optical waveguides. The ring resonators are coated with an organic electro-optic cladding layer and are configured to switch wavelength selected optical signals between the optical bus and the add/drop optical waveguides in response to control voltages applied to the organic electro-optic cladding layer. The individual ring resonators of the ROADM can be independently modulated and tuned to filter specific wavelengths.

The present invention provides a directionless optical architecture for reconfigurable optical add/drop multiplexers (ROADMs) and wavelength selective switches (WSSs). The directionless architecture utilizes a directionless wavelength switch coupled between client devices and ROADMs/WSSs to eliminate the need to hard-wire client devices to a wavelength division multiplexed (WDM) network. Accordingly, client device connections can be automatically routed without manual intervention to provide a highly resilient network design which can recover route diversity during failure scenarios. Additionally, the present invention minimizes deployments of costly optical transceivers while providing superior resiliency. Further, the present invention couples the directionless optical architecture and associated optical protection mechanisms with existing mesh restoration schemes to provide additional resiliency.

The present disclosure provides reconfigurable optical add drop multiplexer (ROADM) node automatic topology discovery systems and methods providing a mapping of optical connections within a mesh optical network that includes tunable lasers and multi-degree ROADM's with colorless/directionless add/drop. The present disclosure may include additional transceiver, receiver, and add/drop filter equipment integrated in or disposed at a ROADM degree. This equipment supports a so-called topology wavelength which is one of a plurality of wavelengths supported by a wavelength division multiplexed (WDM) system that is dedicated and used solely for topology discovery. The topology wavelength may be utilized by the system to detect interconnects between ROADM degrees and between XCVRs/CDMDs. Further, the automated topology discovery may be integrated within a management system and/or control plane.

A system and method for dynamically adding/dropping wavelengths in a reconfigurable optical add-drop multiplexer (ROADM) transport 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 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.

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 system and method for dynamically adding/dropping wavelengths in a reconfigurable optical add-drop multiplexer (ROADM) transport network is disclosed. The system includes a plurality of M×N wavelength selective switches (WSS) for locally dropping selected wavelengths at a node, where each M×N WSS has M inputs connected to optical fan-out devices in each of M network degrees, and a plurality of M×N wavelength selective switches for locally adding selected wavelengths to a node, where each M×N WSS has M outputs connected to optical fan-in devices in each of M network degrees. Several expedients of M×N wavelength selective switches comprising M switching elements for use in the system are also disclosed.

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.

A reconfigurable optical add drop multiplexer (ROADM) includes local interfaces at which optical signals of different wavelengths are locally input into the ROADM, and a network interface configured to connect the ROADM to a network from which multiplexed optical signals of different wavelengths are transmitted to the network. In a first configuration, the ROADM is configured to transmit from the network interface to the network multiplexed signals of different wavelengths having a first minimum frequency difference. In a second configuration, the ROADM is configured to transmit from the network interface to the network multiplexed signals of different wavelengths having a second minimum frequency difference. The second minimum frequency difference is greater than the first minimum frequency difference. This arrangement reduces the power of four wave mixing cross products produced when optical signals of three wavelengths are multiplexed and transmitted from the ROADM to NZDSF or DSF fiber types.

The invention discloses a reconfigurable optical add drop multiplexer (ROADM) based on M*N ports of silicon substrate liquid crystal. The ROADM comprises an optical fiber collimator input array with M ports, a spherical reflector, a body optical grating, an LCoS Opto-VLSI chip, a lens and an optical fiber collimator output array with N ports. The ROADM based on M*N ports of LCoS is realized. An optical system inside the equipment is unique in design, exquisite in structure, and good in function, uses the high-density scoring body grating as a dispersion element, adopts a method that phase gratings of different two-dimension orientations are loaded on an LCoS chip, and realizes efficient and flexible assignments of a large scale optical integrated chip on an incident wave length passage through changing the period of the grating and grating orientation modulation light beam phases. The ROADM has a high port number and optimized spectrum flexibility, has the functions of dispersion adjustments, pulse shaping and the like, and can conduct remote control and upgrade conveniently through software.

This invention relates to provisioning wavelength-selective switches and reconfigurable optical add-drop multiplexers to minimize the bandwidth narrowing effect from the optical filters. Novel architectures and methods are disclosed that can significantly reduce bandwidth-narrowing on channels in a reconfigurable WDM network where a large number of optical filter elements are cascaded. Instead of blocking unused channels as in the prior art, unused channels are selectively provisioned depending on the state of their adjacent channels. Unused adjacent channels of an active channel are provisioned to follow the same path as the active channels. As each channels is deployed, the channel frequency is selected so as to minimize bandwidth narrowing.

Switching architectures for WDM mesh and ring network nodes are presented. In mesh networks, the switching architectures have multiple levels - a network level having wavelength routers for add, drop and pass-through functions, an intermediate level having device units which handle add and drop signals, and a local level having port units for receiving signals dropped from the network and transmitting signals to be added to the network. The intermediate level device units are selected and arranged for performance and cost considerations. The multilevel architecture also permits the design of reconfigurable optical add/drop multiplexers for ring network nodes, the easy expansion of ring networks into mesh networks, and the accommodation of protection mechanisms in ring networks.

The invention discloses a realization method of an optical label, and the realization method comprises the following steps: carrying out the domain division of an optical network according to the nodes of an ROADM (reconfigurable optical add-drop multiplexer) and distributing one or multiple label signal frequencies for each domain; transferring the distributed label signal frequencies among the nodes of the ROADM and/or among the wavelengths in the nodes of the ROADM according to the preset time division rule in each domain; and transmitting label signals according to the label signal frequencies used by the wavelengths to transfer. The invention also discloses a realization system of the optical label. The scheme in the invention realizes the purpose of transmitting the label signals which have the multiple numbers of the wavelengths, reduces the requirements of the system on the label frequencies and is beneficial to the extraction of the label signals through fewer label signal frequencies.

Provided is an optical network node device. According to the optical network node device, a planar lightwave circuit (PLC) based or a blocker based 4-terminals ROADM can be used in a node of at least degree 3, a proceeding direction of a wavelength channel can be changed in an electrical cross connect switch, and transmission in a unit smaller than a wavelength channel can be cross connected, dropped, and added, or transmission capacity can be redistributed in the electrical cross connect switch. Accordingly, efficient transmission in a small capacity and large capacity transmission of a wavelength channel can be performed simultaneously, and thus an optical network can be effectively managed. Also, since the node of at least degree 3 uses the PLC based or a blocker based reconfigurable optical add drop multiplexer (ROADM), the node of at least degree 3 can use the same ROADM module as a node of degree 2. Accordingly, the optical network node device has an advantage in manufacturing and managing a node.