Abstract: Cable communication systems and methods to provide voice and/or data services to subscriber premises via a cable plant that conveys upstream information over an upstream path bandwidth, and a cable modem system including one or more demodulation tuners to receive and demodulate one or more upstream radio frequency (RF) signals. One or more RF signals include an encoded carrier wave having a carrier frequency of between 5 MHz and 16.4 MHz that is modulated using a Time Division Multiple Access (TDMA) protocol or an Advanced Time Division Multiple Access (ATDMA) protocol and quadrature amplitude modulation (QAM) with voice and/or data information constituting at least some of the upstream information. An aggregate deployed upstream capacity of the one or more RF signals to convey the upstream information in a portion of the upstream path bandwidth between 5 MHz and 16.4 MHz is at least approximately 12 Megabits per second (Mbits/s).

Abstract: The present disclosure relates to a fiber optic network configuration having an optical network terminal located at a subscriber location. The fiber optic network configuration also includes a drop terminal located outside the subscriber location and a wireless transceiver located outside the subscriber location. The fiber optic network further includes a cabling arrangement including a first signal line that extends from the drop terminal to the optical network terminal, a second signal line that extends from the optical network terminal to the wireless transceiver, and a power line that extends from the optical network terminal to the wireless transceiver.

Abstract: The present invention discloses a time/wavelength-division multiplexed passive optical network (TWPON), which has an optical splitter (21) and a waveguide grating router (WGR) (22) disposed at a remote node (RN) (20). The optical splitter (21) and the WGR (22) can be connected in a cascade or in a parallel such that the present invention can use less number of wavelengths to increase transmission capacity or increase the number of users. The TWPON of the present invention can provide TDM-PON, WDM-PON, and Hybrid PON co-existing platform with less wavelengths channel fault monitoring mechanism.

Abstract: An apparatus comprising a mode coupler configured to couple a plurality optical signals into a plurality of modes, and a receiver coupled to the mode coupler and configured to detect the modes to obtain the optical signals, wherein the optical signals are coupled from single mode fibers. Also disclosed is an apparatus comprising a plurality of single mode waveguides configured to transport a plurality of single mode signals, and a detector coupled to the single mode waveguides and configured to detect the single mode signals, wherein the single mode signals are substantially coupled without loss from the single mode waveguides to the detector. Also disclosed is a method comprising receiving a plurality of single mode optical channels, coupling the single mode optical channels into a multimode channel, and detecting the optical modes corresponding to the channels in the multimode channel.

Abstract: Disclosed is a wavelength-shifted bidirectional WDM optical network including: an optical line terminal including an optical line terminal (OLT) including a first optical transmitter transmitting a downstream WDM optical signal, a first high-density wavelength multiplexer/demultiplexer wavelength-multiplexing the downstream WDM optical signal or wavelength-demultiplexing a wavelength-multiplexed upstream WDM optical signal, and a first optical receiver receiving the wavelength-demultiplexed upstream WDM optical signal; a remote node (RN) including a second high-density wavelength multiplexer/demultiplexer shifting a center wavelength of the upstream WDM optical signal and wavelength-multiplexing the upstream WDM optical signal with the shifted center wavelength or wavelength-demultiplexing the wavelength-multiplexed downstream WDM optical signal; and multiple optical network units (ONUs) each including a second optical transmitter transmitting the upstream WDM optical signal and second optical receiver receiv

Abstract: Devices, systems and methods for run-time reassignment of the interconnection between devices pertaining to a Physical (PHY) layer and devices pertaining to a Media Access Control (MAC) layer, with no packet loss or with at most one packet lost are provided. The strategies employed by these devices, systems and methods used REMOTE FAULT, PAUSE and IDLE PATTERN messages. The devices may be interconnected via a reconfigurable optical crossbar.

Abstract: One embodiment provides a system for power saving in an Ethernet Passive Optic Network (EPON). The system includes an optical line terminal (OLT), an optical network unit (ONU), a traffic-detection module configured to detect status of traffic to and from the ONU, and a power-management module configured to place the ONU in sleep mode based on the detected traffic status. The ONU includes an optical transceiver that includes an optical transmitter configured to transmit optical signals to the OLT and an optical receiver configured to receive optical signals from the OLT.

Abstract: Provided are a wavelength division multiplexing-passive optical network (WDM-PON) in which a reflective semiconductor optical amplifier (RSOA) is used as each optical transmitter of an optical line termination (OLT) and an optical network unit (ONU) and additional spectrum-sliced light is injected into RSOAs of each of the OLT and the ONU, and a WDM-PON that is combined with time division multiple access (TDMA) technology, by which the number of included ONUs increases and conventional TDMA ONUs can be used.

Abstract: An optical network unit (ONU) accesses services provided by multiple optical line terminals (OLTs) in a wavelength division multiplexing (WDM) passive optical network (PON). The ONU receives downstream signals from a first plurality of OLTs through a designated port of an arrayed waveguide (AWG). At any given time, the bandpass filter module can select any one of a first plurality of AWG cycles allocated to the first plurality of OLTs. Based on received downstream signals, the ONU transmits upstream signals to a second plurality of OLTs through the designated port of the AWG. At any given time, the bandpass filter module and a transmitter of the ONU can select any one of a second plurality of AWG cycles allocated to the second plurality of OLTs. The ONU may be configured with a plurality of receivers and transmitters, whereby it is enabled to simultaneously subscribe to a plurality of AWG cycles.

Abstract: An optical access network (OAN) system is provided. In the system, a remote radio unit (RRU) receives and sends a wireless signal and implement conversion between the wireless signal and a first frequency signal; an optical network device receives and sends the wireless signal, and implement conversion between the wireless signal and the first frequency signal and conversion between the first frequency signal and a fiber transmission signal; an optical distribution network (ODN) connected to the optical network device transmits the fiber transmission signal; an optical line terminal (OLT) device receives and sends the fiber transmission signal, and implements conversion between the fiber transmission signal and a second frequency signal, conversion between the second frequency signal and a base band signal, and conversion between the base band signal and a signal of another standard protocol.

Abstract: An approach is provided for integrating one or more fiber switches in a passive optical network. A platform generates a command signal to control a splitter hub of a passive optical network, the splitter hub being configured to communicate with a plurality of optical network terminals that respectively serve a plurality of customer premises. The splitter hub includes a fiber switch configured to provide switching between one of a plurality of input ports and one of a plurality of output ports of the splitter hub.

Abstract: An apparatus comprising an optical line terminal (OLT) configured to couple to a plurality of optical network units (ONUs) and transmit a plurality of downstream frames to the ONUs, wherein each of the downstream frames comprises a plurality of forward error correction (FEC) codewords and a plurality of additional non-FEC encoded bytes that comprise synchronization information that is protected by Header Error Control (HEC) code. An apparatus comprising a processing unit configured to arrange control data, user data, or both into a plurality of FEC codewords in a downstream frame and arrange a physical synchronization sequence (PSync), a superframe structure, and a Passive Optical Network-identifier (PON-ID) structure in a plurality of additional non-FEC encoded bytes in the downstream frame, and a transmission unit configured to transmit the FEC codewords and the additional non-FEC encoded bytes in the downstream frame within a 125 microsecond window.

Abstract: Disclosed are a system for providing a WDM-based wireless optical transport network and a method for transmitting a wireless optical signal using the same. The system for providing a WDM-based wireless optical transport network, includes: a central office terminal (COT) for bilaterally transmitting wireless optical signals of different unique wavelengths; and a plurality of remote terminals (RTs) connected to the COT in a ring, for dropping a wireless optical signal having a corresponding unique wavelength from the wireless optical signals transmitted from the COT, for adding a corresponding optical transmission signal to wireless optical signals of the remaining unique wavelengths except for the corresponding unique wavelength of the dropped wireless optical signal, and for bilaterally transporting the wireless optical signals to which the corresponding optical transmission signal is added.

Abstract: A system and method of extending a trunk reach of a passive optical network, PON. An optical network termination, ONT, processes upstream and downstream PON signals on a trunk fiber with an optical line termination, OLT, at a central office. An extender device may be implemented at a user's home, a remote node, or at the central office. The extender device includes a time division multiplexing, TDM, unit for multiplexing the PON signals, a forward error correction, FEC1 unit for applying an FEC to the PON signals, and a regenerator for applying optical-electrical-optical, OEO, regeneration to the PON signals.

Abstract: An optical transmitter disabling device for controlling an optical transmitter, particularly of an optical network termination node of a passive optical network comprising a monitoring module and a disabling module, the monitoring module being adapted to determine at least when the optical transmitter is active, the disabling module being adapted to be connected to an activation input of the optical transmitter and wherein the disabling module is adapted to interrupt an activation signal to the optical transmitter at least when the monitoring module determines that the optical transmitter is active outside of a predetermined time interval.

Abstract: In the communication system, a master station is coupled to slave stations by a fiber network comprising a splitter and a reach extender, the master station includes a first bandwidth control section which determines, based on a request from each slave station, a first data amount of a signal transmitted in a first cycle, the reach extender includes: a distance measurement section which measures a distance or a time between the reach extender and each slave station; and a second bandwidth control section which determines a second data amount and transmission timing of a signal based on a request from each slave station and the first data amount, and each slave station transmits a signal with a data amount, which the first bandwidth control section determined based on a data amount and transmission timing determined in second cycles, to the master station in the first cycle.

Abstract: There are provided multiple candidates for FEC codes selectable for each of the ONTs. An OLT is provided with: means for storing redundancy and a code length of each FEC code in a table; means for selecting an FEC code; means for encoding or decoding data using the selected FEC code; means for calculating a bandwidth in consideration for the FEC redundancy and the code length with reference to the table during band assignment calculation; and means for notifying the destination ONT of the selected FEC code.

Abstract: A system for serving N optical communication lines by a redundant set of modules in an optical network; where the set of modules comprises N>1 main modules and one backup module, N optical splitters, 2N fiber connections and a control means. In the system, each of the N optical splitters is connected to two different modules of the set by two respective fiber connections out of the 2N connections, while each of the N optical splitters is also coupled to one of the N optical communication lines. The arrangement is such that the control means selectively activates/inactivates any of the fiber connections for respectively enabling/blocking transfer of data there-along; the control means thus ensures that each specific line of the N optical communication lines is always served by either one or another of two different modules.

Abstract: The present disclosure discloses a passive optical network (PON) user terminal comprising a passive optical network interface unit (PONIU) having access to a PON system, a service data distribution unit (SDDU) connected to the PONIU for distributing service data, a plurality of service processing units (SPUs) for receiving and accordingly processing the service data distributed by the SDDU, a power source for providing power to the above units, and a power supply control unit (PSCU) for controlling the activating/deactivating of the energy-saving power supply to the SPUs, the SDDU, and the PONIU. The present disclosure further provides a method for controlling the PON power supply and for reporting the power supply state. The present disclosure allows control of the energy usage of the PON user terminal to save power when a service in the PON user terminal is not used or when the user terminal uses a backup power source to supply power.

Abstract: An optical wavelength division node includes an optical splitter, a plurality of optical circulators, and a colorless light source module. The optical splitter receives and splits a downstream signal light source into a first-path and a second-path signal light source. The optical circulator in a first-order position receives and transmits the first-path signal light source to an optical network unit in a first-order position, and receives a return signal and passes it to a next optical circulator, and finally the optical circulator in a last-order position receives the return signal and transmits it. The colorless light source module receives the second-path signal light source and the return signal transmitted by the optical circulator in a last-order position, and uses the second-path signal light source to modulate the return signal to generate an upstream signal light source to be transmitted to the optical line terminal by the optical splitter.

Abstract: A system, an unbundling optical line terminal (OLT), and a method are described herein that allow at least two service providers (SPs) to use individual fibers of an optical distribution network (ODN). In one embodiment, the unbundling OLT includes one or more wavelength division multiplexing-passive optical network (WDM-PON) line cards and one or more SP uplink cards that enable multiple SPs to each utilize one uplink port to access individual wavelengths of one or more passive optical networks (PONs). In another embodiment, the unbundling OLT includes one or more point-to-point line (p2p) line cards (e.g., p2p fiber Ethernet line cards) and one or more SP uplink cards that enable multiple SPs to each utilize one uplink port to access one or more individual fibers.

Abstract: An optical transmission system is provided. The optical transmission system includes a user side optical repeater device (ORD), a central office side ORD, and wavelength multiplexing and wavelength de-multiplexing functions (MUX/DEMUX). The user side optical repeater device (ORD) is to be connected with a user side optical network unit (ONU), transmits data in two ways, and is used for wavelength division multiplexing (WDM). The central office side ORD is to be connected with a central office side optical line terminal (OLT), transmits data in two ways, and is used for WDM. The wavelength multiplexing and a wavelength de-multiplexing functions (MUX/DEMUX), are used for relaying between the user side ORD and the central office side ORD.

Abstract: A system comprises an optical network terminal (ONT) that terminates an optical fiber link of an optical network to provide an optical network interface. The ONT may include an optical module that receives optical signals via the optical fiber link and converts the optical signals to electrical signals and an optical media access control (MAC) unit that converts at least some of the electrical signals to data units. The optical MAC unit may be selectively configurable to support a plurality of optical network protocols. For example, the optical MAC unit is selectively configurable to support two or more of BPON protocol, a GPON protocol, a GEPON protocol and an active Ethernet protocol. In one instance, the optical MAC unit is selectively configurable to support at least one active optical network protocol and at least one passive optical network protocol.

Abstract: A method (100) of operation in a passive optical network system (600) includes transmitting wave division multiplexed data in a downstream link (617) of an optical distribution network (618) using a plurality of optical line terminals (601,602,603). Each optical line terminal (601,602,603) operates at a unique wavelength, and is synchronized to each other optical line terminal by a common reference (643). Upstream data is received from an upstream link (619) of the optical distribution network on a shared common upstream wavelength (620).

Abstract: Various methods and apparatuses are described for a wavelength division multiplexing passive optical network (WDM-PON) that performs bi-directional communication. The WDM-PON may include two or more remote distribution nodes in between a central office and the most distant optical network unit. Each remote distribution node is located in a physically separate location. A first remote distribution node has two or more optical network units connected to the first remote distribution node. Each remote node separates one or more wavelength channels from a composite optical signal distributed through that remote distribution node.

Abstract: Provided is an optical access network capable of realizing protection control without affecting an E-PON for providing an Ethernet service. In the optical access network comprising the E-PON having a transmission line which is duplexed between an OLT and a plurality of ONTs, the OLT includes a layer-2 (L2) control section in which a protocol, in which protection control information is provided, as a protocol structure, above an Ethernet media access control (MAC), is mounted. Further, the OLT has a protocol structure in which the protection control information is provided independently from the Ethernet MAC to transfer user data and the protection control information.

Abstract: A head-end circuit comprises first and second continuous light sources, first and second modulators. The first and the second continuous light sources provide first and second optical signals respectively corresponding to first wavelength and second wavelength, which is different from the first wavelength. The first modulator modulates the first optical signal based on first clock signal to generate an optical clock signal. The second modulator modulates the second optical signal based on downlink data to generate optical downlink data with the carrier of the second optical signal. The optical clock signal and the optical down link data are outputted to a remote antenna unit via first fiber path.

Abstract: Optical fiber-based distributed communications components and systems employing wavelength division multiplexing (WDM) for enhanced upgradability. The system comprises a plurality of downlink optical transmitters configured to receive downlink electrical radio frequency (RF) signals from a plurality of RF sources and convert the downlink electrical RF signals into downlink optical RF signals. The system also has a wavelength division multiplexer configured to multiplex downlink optical RF signals into a plurality of downlink wavelengths over a common downlink optical fiber connected to a plurality of remote antenna units (RAUs). In this manner, additional downlink optical fibers are not required to support providing additional RAUs in the system. Wavelength-division de-multiplexing can avoid providing additional uplink optical fibers to distribute uplink signals to RAUs added in the system.

Abstract: A method and apparatus for providing link establishment in the access segment of the communications network using broadband multi-wavelength LED are disclosed. In one embodiment, such links may be established in point-to-point, point-to-multipoint, multipoint-to-multipoint, or ring format depending on the topology required for optimized access network build-out.

Abstract: Proposed is an efficient method of configuration of a transmitter and a receiver for realizing an optical transmission/reception module apparatus including at least one transmission wavelength and two or more reception wavelengths over a time division multiple access passive optical network or an optical network using multiple transmission/reception wavelengths. Further, proposed is a method of configuration of an apparatus which enables optical alignment and assembly in a single package by using a single lens and three different WDM optical filters for a reception module capable of receiving four wavelengths.

Abstract: A passive optical network (PON) comprises an Optical Line Termination (OLT), an Optical Distribution Network (ODN), and a plurality of Optical Network Terminations (ONTs), wherein the OLT includes an OLT Dense Wavelength Division Multiplexing (DWDM) multiplexer, an OLT CWDM demultiplexer, and a Wavelength Division Multiplexing (WDM) filter, wherein the OLT DWDM multiplexer and the OLT CWDM demultiplexer are coupled to the WDM filter, wherein the ODN includes a WDM filter, a DWDM demultiplexer, and a plurality of fanout splitters, wherein the DWDM demultiplexer is coupled to the WDM filter, wherein the WDM filters are coupled to one another and wherein a portion of the plurality of ONTs that are associated with a wavelength are coupled to one of fanout splitters that is associated with the wavelength.

Abstract: An optical network unit according to the present invention is provided as comprising a configuration that component units built therein are grouped for at least two sheets of substrate modules and arranged thereat. There are provided individual embodiments: (a) arranging an L2 layer and a part of the component unit of an L1 layer at a first substrate module, meanwhile, arranging the left part of the component unit of the L1 layer at a second substrate module; (b) arranging the component units of the L1 layer and of the L2 layer at the first substrate module and the second substrate module individually by grouping therefor; and (c) arranging the component units of the L2 layer and of the L1 layer at the first substrate module and the second substrate module respectively.

Abstract: A passive optical network system and method in which at least part of the data is optically transmitted through a single optical fiber using a wavelength division multiplexing technique, with a plurality of signals being carried through the fiber in each direction, a different wavelength being used for each of the multiplexed upstream and downstream signals. The system may be retrofitted into existing telecommunications system to provide a multi-fold increase in the available bandwidth of long-distance optical fiber transmission.

Abstract: One or more overlay wavelengths are applied to a GPON architecture to provide sufficient, cost-effective forward bandwidth per home for targeted, unique narrowcast services to allow traditional HFC operators to use a PON architecture with their existing HFC equipment. A separate return path capability using a separate coaxial cable with RF signals to the GPON may also be used. This return capability may be provided either by a fiber optic link or coaxial link from the home.

Abstract: A method of synchronizing with a data transmission in a passive optical network, wherein the data transmission includes a plurality of data transmission frames each having i) a known transmission duration, and ii) a start boundary identified by a predetermined synchronization pattern. The method includes comparing a plurality of data patterns within the data transmission to at least part of a predetermined synchronization pattern; providing a comparison result for each comparison having a match between a data pattern and the at least part of the predetermined synchronization pattern; assigning a frame tracking signal to each one of the plurality of comparison results occurring within the known transmission duration; comparing one or more subsequent data patterns occurring in the data transmission to at least part of the predetermined synchronization pattern for each assigned frame tracking signal; and generating a synchronization signal associated with a selected one of the frame tracking signals.

Abstract: The subject matter disclosed herein relates to synchronizing network timing. In one particular example, network timing may be synchronized using reflected signals.

Abstract: A central office optical line terminal (S-OLT) and a local optical line terminal (L-OLT) are connected to through a transmission link form a transmission network. The S-OLT sends service data sent by a service network to the L-OLT through a transmission channel, receives the service data sent by the L-OLT from the transmission channel, and sends the service data to the service network. The L-OLT receives the service data sent by the S-OLT from the transmission channel and sends the service data to an optical network unit (ONU), and sends the service data sent by the ONU to the S-OLT through the transmission channel. Thus, the service data of the L-OLT is sent to the service network through the S-OLT, thereby solving a problem in the existing PON that the service data requires another transmission of the transmission network to reach the service network.

Abstract: A system comprises an optical network terminal (ONT) that provides an interface to a passive optical network (PON). The ONT is coupled to a subscriber gateway device via at least one cable. The ONT may be located outside a subscriber premises while the subscriber gateway device may be located within the subscriber premises. The ONT converts optical signals received from PON to electrical signals and transmits the electrical signals to the subscriber gateway device without performing any MAC layer functions. The subscriber gateway device includes an optical media access control (MAC) unit that converts the electrical signals into MAC layer signals and a gateway unit that distributes the MAC layer signals to one or more subscriber devices. In this manner the MAC and gateway layer functions are relocated from the ONT to the subscriber gateway device.

Abstract: There is provided a customer premises optical network unit (ONU) capable of reading management signals and of outputting data through an external node by using I2C serial interfaces. In the ONU, an ONU functioning section has another serial signal terminal and is connected with a first management processing section through a sub-serial transmission path. The first management processing section is also connected with a MSA interface module through an additional monitoring signal transmission path and a monitoring signal transmission path. The monitoring signal transmission path on the side of the MSA interface module is connected with a sub-I/F section. A part of management signals set in an OAM layer of a signal transmitted between an OLT and the ONU may be outputted to an external node by using the first management processing section, the additional monitoring signal transmission path and the monitoring signal transmission path.

Abstract: In a passive optical communication network system, an optical signal OCDM-coded is transmitted from an OLT to a first port of a circulator, which in turn transfers the signal from its second port to one end of a first SSFBG. The first SSFBG then decodes the signal of one channel to output the decoded signal from its one end to the second port of the circulator, which in turn transmits the decoded signal from its third port to an ONU. When the ONU transmits an optical signal to the third port of the circulator, the circulator transfers the signal from its fourth port to one end of a second SSFBG, which in turn encodes the signal to output the encoded signal from its one end to the fourth port of the circulator. The circulator then transmits the encoded signal from its first port to the OLT.

Abstract: A signal transmission system for a peer-to-peer optical network. The system includes an optical line terminal, an optical distribution node, and a plurality of optical network units. The optical network unit and the optical distribution node are connected in a tree distribution having an ordered relation. The optical line terminal transmits optic signals via the optical distribution node to a first ordered optical network unit, to allow the first ordered optical network unit to process the optic signals and to generate combined optic signals, which are transmitted to a next ordered optical network unit via the optical distribution node. The above steps are iterated, until a last ordered optical network unit transmits combined optic signals to the optical line terminal via the optical distribution node.

Abstract: An optical transceiver includes an internal optical fiber coupled to optical sub-assemblies in the transceiver and is capable of maintaining a bend diameter of the internal optical fiber above a minimum bend diameter. The optical transceiver thus allows optical fiber to be used within a relatively small space within a housing of the optical transceiver without significant power loss in the optical signal carried on the optical fiber. The optical transceiver may be a small form-factor pluggable (SFP) transceiver used, for example, in an optical line terminal (OLT) and/or optical networking unit (ONU) in a wavelength division multiplexed (WDM) passive optical network (PON).

Abstract: A method implemented in an optical line terminal (OLT) for reducing adverse effects from a rogue optical network unit (ONU) in a passive optical network (PON), comprising determining with a processor that the rogue ONU is transmitting in violation of pre-specified parameters, and sending at least one message to a plurality of ONUs to change a transmitting wavelength from a first wavelength to a second wavelength.

Abstract: Methods and apparatuses to provide an “Open access” service model using wavelength division multiplexing (“WDM”) passive optical networks (“PONs”) are described. A cross-connect is used to supply a first set of optical signals corresponding to a first service provider and a second set of optical signals corresponding to a second service provider to a WDM multiplexer/demultiplexer. The WDM multiplexer/de-multiplexer is used to multiplex and transmit the first set and the second set to a remote location. Another WDM multiplexer/de-multiplexer at the remote location is used to de-multiplex the first set and the second set. The first set may be supplied to a first user and the second set may be supplied to a second user. Transceivers coupled to the cross-connect may be used to generate the optical signals. For one embodiment, the transceivers include a wavelength-locked light source. For one embodiment, the transceivers are alike.

Abstract: In a passive optical network, a downstream transmission rate from an OLT to multiple ONTs can be optimized by matching a transmission scheme for frames addressed to a channel to the downstream transmission characteristics of the channel. An FEC coding can be made channel dependent so that channels with low error rates can use minimal protection, and therefore minimal overhead, while channels with high input bit error rates can use the level of FEC coding required to produce a desired output bit error rate.

Abstract: The present invention relates to a transceiver unit in a PON, Passive Optical Network, for receiving an optical input signal and transmitting an amplitude modulated optical output signal. Further, the present invention relates to a method in a transceiver unit for receiving an optical input signal and transmitting an amplitude modulated optical output signal.

Abstract: An optical network and an optical signal modulation method thereof are provided. The optical network includes an optical fiber and a remote node (RN). The RN receives a continuous carrier wave from the optical fiber and modulates the continuous carrier wave to generate a first frequency offset carrier wave The frequency of the first frequency offset carrier wave is different from that of the continuous carrier wave. A first user device re-modulates and loads data to the first frequency offset carrier wave to generate a first upstream signal. The frequency of the first upstream signal is the same as that of the first frequency offset carrier wave. The RN inputs the first upstream signal into the optical fiber.

Abstract: A data center network comprising with an all-optical core network which includes a number of separate all-optical networks to connect clusters of computer network equipment at network nodes. Circuit modules in the data center network each includes a memory bank to provide queues to store information scheduled to be transmitted optically through the all-optical core network. Each circuit module also includes a lambda port module which includes a number of optical mux-demux units and an equal number of lambda ports designed to provide communication between the mux-demux units and the memory bank via a number of optical transceivers. In preferred embodiments all logic communication circuits through the core network are all optical fibers. The present invention creates non-interfering circuits by means of their spectral, spatial and temporal separation from each other.

Abstract: A wavelength-selectable laser device generally includes an array of laser emitters and a filtered external cavity for filtering light emitted from the laser emitters and reflecting different wavelengths back to each of the laser emitters such that lasing occurs at different wavelengths for each of the laser emitters. Each laser emitter includes a gain region that emits light across a plurality of wavelengths including, for example, channel wavelengths in an optical communication system. The filtered external cavity may include a dispersive optical element that receives the light from each of the laser emitters at different angles and passes or reflects different wavelengths of the light at different angles such that only wavelengths associated with the respective laser emitters are reflected back to the respective laser emitters. By selectively emitting light from one or more of the laser emitters, one or more channel wavelengths may be selected for lasing and transmission.

Abstract: A wavelength-selectable laser device providing spatially-selectable wavelength(s) may be used to select one or more wavelengths for lasing in a tunable transmitter or transceiver, for example, in a wavelength division multiplexed (WDM) optical system such as a WDM passive optical network (PON). The wavelength-selectable laser device uses a dispersive optical element, such as a diffraction grating, to disperse light emitted from a laser emitter and to direct different wavelengths of the light toward a reflector at different spatial positions such that the wavelengths may be selected by allowing light to be reflected from selected spatial position(s) back into the laser emitter. Thus, the reflected light with a wavelength at the selected spatial position(s) is allowed to complete the laser cavity.