Abstract: An apparatus having n-number of working cross-connects for cross-connecting an n-bit input signals arriving from a plurality of input paths on a per-bit basis; n-number of first logic circuits for calculating the exclusive-ORs of each said n-bit and applying outputs to a standby cross-connect for providing outputs; n-number of second logic circuits for calculating the exclusive-ORs of said output signals from each of said working cross-connects and from the single standby cross-connect; and third logic circuits for selecting output signals of said working cross-connects and outputs of the second logic circuits. The apparatus detects the occurrence of an abnormality in working cross-connects by monitoring the outputs of the second logic circuits, identifies the faulty cross-connect by successively turning off one of the n-inputs to the first and second logic circuits, and select outputs from the second logic circuits instead of from the faulty cross-connect by using the third logic circuits.

Abstract: A bit-rate-transparent electrical space-division switching matrix is employed in an optical cross-connect and the input/output stage is constructed from simple, broadband optical receivers and transmitters. Since the switching matrix operates in unclocked manner, i.e. its switching function is not based on internal bit timing and frame timing, arbitrary signals can be switched though transparently at almost any bit rate, independently of the protocol-type being used. The inputs and outputs likewise operate fully independently of bit rate and protocol, since they only implement an O/E conversion or O/E conversion. By virtue of this structure, a simply constructed but extremely powerful optical cross-connect is created that can be employed equally for all types of optical signals within the stipulated wavelength-range.

Abstract: A system for providing high connectivity communications over a packet-switched optical ring network comprises a core optical ring having at least one node, the node being coupled to a subtending system by an optical crossbar switch, a source for generating a set of packets, a stacker for forming a first composite packet from the set of serial packets, the stacker coupled to the optical crossbar switch, and the stacker further coupled to the source for generating the set of packets, the first composite packet being parallel packets in a single photonic time slot, the first composite packet to be added to the core optical ring in a vacant photonic time slot via the optical crossbar switch, a second composite packet propagating on the core optical ring destined to be dropped at the node for further distribution on the subtending system via the optical crossbar switch, an unstacker for serializing the second composite packet dropped at the node, the unstacker coupled to the optical crossbar switch and a detector

Abstract: An optical multi/demultiplexing circuit includes at least one phase generating optical coupler and an optical delay line coupled to the phase generating optical coupler. The phase generating optical coupler consists of at least one input and at least two outputs. At least one of the phase generating optical coupler has a wavelength dependent or frequency dependent output phase difference in the passband of the circuit so that it can change the transmittance characteristics of the optical multi/demultiplexing circuit.

Abstract: A packet-switched WDMA ring network has an architecture utilizing packet stacking and unstacking for enabling nodes to access the entire link capacity by transmitting and receiving packets on available wavelengths. Packets are added and dropped from the ring by optical switches. A flexible credit-based MAC protocol along with an admission algorithm enhance the network throughput capacity.

Abstract: A system and apparatus for dropping and adding optical data streams in an optical communication network uses a photonic switching fabric for dropping but not adding optical data streams, and uses a combiner external to this photonic switching fabric for combining passed optical data streams from the photonic switching fabric together with added optical data streams. The added optical data streams are not limited to the wavelengths of the dropped optical data streams. The photonic switching fabric may be a Micro Electro Mechanical System (MEMS) that uses single-sided mirrors configurable to drop but not add optical data streams.

Abstract: This invention discloses an optical burst transmission system in which an optical generator generates Type 1 lightwaves having different wavelengths corresponding to transmission lines and having undergone intensity modulation with obtained data; a broad spectrum optical generator generates, by incorporating Type 2 lightwaves, a Type 3 lightwave using a fewer light emitting devices than the number of the Type 1 lightwaves, each Type 2 lightwaves having a corresponding wavelength apart from Type 1 lightwave's wavelength with an FSR interval and having undergone the intensity modulation with clock signals; an optical multiplexer multiplexes the Type 1 and Type 3 lightwaves to output the combination to each transmission line; and an optical routing unit extracts, from the combination, pairs of one Type 1 lightwave and one Type 2 lightwave having the corresponding wavelength, and guides pairs to each transmission line corresponding to the Type 1 lightwave's wavelength in each pair.

Abstract: A wavelength selective switching device and method for selectively transmitting optical signals based on wavelength utilizes diffraction to spatially separate the optical signals of different wavelengths such that the optical signal of a selected wavelength can be selectively transmitted. The wavelength selective switching device selectively rotates the polarization components of the optical signals such that the polarization states of the polarization components are the same in both incoming and outgoing directions at the diffraction grating. Thus, a diffraction grating with a high grating line frequency (e.g. greater than 900 grating lines per mm for signals in the 1550 nm wavelength range) can be used for diffracting the polarization components of the optical signals in both the incoming and outgoing directions.

Abstract: A frequency agile cable modem termination system which is configured to receive cable TV or other broadband signals on a frequency allocated basis. Cable TV headend may receive cable TV modem or other signals via optical/electrical converters and other links, and route those signals through a frequency multiplexer to divide individual feeds into separated frequency slots. The cable modem termination system may then have receivers tuned to individual slots allocated to data feeds, such as Internet, video, telephony or other sources, and route those sources over the Internet. Upon a failure condition within any given receiver or other component, a backup cable modem termination system, connected to the same common bus as the main or active system, may be rapidly activated by having backup receivers contained in that unit tuned to appropriate frequencies to pick up the signals within the corresponding band. Reliability and robustness is increased, and cabling requirements are decreased.

Abstract: An optical interconnect comprises an input configured to receive light of a plurality of light wavelengths and a plurality of holographic optical elements. Each element configured to reflect one out of the plurality of light wavelengths and allowing others of the plurality of wavelengths to not be reflected. Each of a plurality of prisms is configured to rotate received light at a different angle than any of the other prisms. For each holographic optical element, one of the plurality of prisms is positioned to receive and rotate light reflected by that holographic element. Each of a plurality of beam splitters is positioned to receive light rotated by a respective one of the plurality of prisms and all the plurality of beam splitters direct light to an output of the optical interconnect.

Abstract: Techniques for dilating and reverse dilating optical channels in an optical system are disclosed. In one particular exemplary embodiment, a technique for dilating optical channels may be realized as a method for dilating optical channels in a system having W optical frequencies. The method comprises receiving a plurality of optical channels each operating at a respective one of the W optical frequencies. The method also comprises converting the optical frequency of each of the plurality of optical channels into a respective converted optical frequency defined by ?+?.f, wherein f represents the optical frequency of each of the plurality of optical channels, and wherein ?=±1 and ? are constant for all of the plurality of optical channels. The method further comprises directing each of the plurality of optical channels based at least in part upon the respective converted optical frequency of each of the plurality of optical channels.

Abstract: An optical cross-connecting device is small in scale of a switch even when a wavelength multiplexed signal to be transmitted through an optical fiber is high density and wide range. Switching of the wavelength multiplexed signals is performed in a first optical switch, switching per wavelength group in a second optical switch is performed for only signals required switching for smaller granularity, and switching per wavelength signals in a third optical switch is performed for only signals required switching for smaller granularity to from the opticall cross-connecting device. By this, even when the wavelength multiplexed signal to be transmitted through the optical fiber is high density and wide band, the optical cross-connecting device can be small in scale of a switch.

Abstract: A selective frequency extractor is disclosed which forwards one or more selected frequencies of a wavelength division multiplex input signal consisting of N channels to one output port and all the other frequencies to another output port. A reconfigurable frequency add and drop multiplexer is also disclosed. The input signal is divided up by a first demultiplexer and routed to a plurality of interleaved stages of optical switches for selectively feeding a plurality of input ports of a multiplexer, whose routing properties are then used for extracting one or more frequencies from the input signal or for reconfigurable frequency add and drop multiplexing.

Abstract: A technique for routing data within an optical network having a plurality of network nodes is disclosed. In one embodiment, the technique is realized by receiving data at a first network node via a first optical signal having a first wavelength. The first wavelength corresponds to a first optical frequency, and the first optical frequency is mapped to a first binary representation. The first binary representation is divided into a first plurality of fields, wherein at least one of the first plurality of fields corresponds to a routing label in a first label stack. A top routing label in the first label stack indicates a second network node. Based at least partially upon the top routing label, the data is transmitted from the first network node to the second network node via a second optical signal having a second wavelength. The first wavelength may be either the same as or different from the second wavelength.

Abstract: There is defined an optical link section which leads from output interfaces of an optical switch equipment to the input interfaces of an optical switch equipment. In-band control channels for every optical links are interposed between the optical switch equipments and an optical multiplex section. The in-band control channels exchanges the optical link attributes specified by the interfaces of the optical switch equipments and the optical link attributes specified by the optical multiplex section, mutually as control messages.

Abstract: A method of establishing communications in an all optical wavelength division multiplexed network. This method is used in networks built from optically connected communication devices (20, 22) that are capable of converting an optical wavelength to at least one other given optical wavelength, and/or directing a given optical wavelength through an ingress and egress port. Communication is facilitated by devices utilizing a set of given optical wavelengths from the electromagnetic spectrum as a carrier to facilitate communication. A plurality of tables (FIG. 2–4) with varying information such as availability, status, functionality, usage, capabilities, and facilities provide a reference for device resources. Communication paths are created between devices by searching the tables (FIG. 2–4) for information regarding available resources needed to create a path, and then utilizing the available resources with or without optical wavelength conversions between devices (20, 22) to construct a communication path.

Abstract: The present invention disclosed herein therefore provides systems and methods of optical packet switching. The present invention further enables systems and methods of all-optical label swapping (AOLS) with optical subcarrier multiplexed addressing for WDM-IP networks.

Abstract: In accordance with the invention, a system and method for providing QoS to packets formatted in accordance with one protocol (e.g., IP or Ethernet) carried over networks that are originally designed to be used with another protocol (e.g., ATM, WDM, or TDM). In one embodiment of the invention, such a switch is modified in order to allow the switch to become “IP-aware.” Such a modified switch can identify IP packets, determine if any packets should be dropped, classify the packets with a queue, and schedule the packets of each queue in a manner that provides quality of service to the packets in the queue. Moreover, some embodiments of a modified switch further include a monitor to keep statistics on the packets in the modified switch, a protection mechanism that monitors fault information for at least part of the network, and a provisioning mechanism that determines normal and backup paths for each connection.

Abstract: A channel allocation apparatus of an OSU in a WDM system includes: an optical signal converter for performing a conversion operation between an E1 data frame and an optical signal; a channel allocating unit for performing a counting operation by a certain unit on the E1 data, detecting an channel allocated to the E1 data or allocating a channel to the E1 data; an E1 framer for reframing the E1 data frame outputted from the optical signal converter to output it to the channel allocating unit, and framing the E1 data outputted from the channel allocating unit to output it to the optical signal converter; and a microprocessor for controlling an operation of the E1 framer. After the E1 data is counted by a certain unit to sequentially identify a plurality of channels, a channel data is assigned to a corresponding channel or a channel data assigned to the channel is detected.

Abstract: The photonic network of the present invention uses a cost-effective DWDM optimized switch architecture allowing the introduction of DWDM into the metro network. In this invention the optical carriers are all generated in the photonic layer at the edge photonic switching node and are allocated out to the photonic access nodes or central core data switch for modulation. This has the advantage of providing the optical carriers to be modulated from a centralized highly stable and precise source, thereby meeting the requirements for DWDM carrier precision, whilst generating these carriers in relatively close proximity to the modulators. Sparse WDM components can be used in the access portion of the network without adversely affecting the ability of the signal to transit the DWDM portion of the core network, since the optical carrier frequency is fixed at the centralized source and is unaffected by these components.

Abstract: An optical fiber ring network includes a plurality of interconnected nodes, each pair of neighboring nodes being interconnected by a pair of optical links. Using coarse wavelength division multiplexing, data is transmitted in both directions over each link, using a first wavelength ?1 to transmit data in a first direction over the link and a second wavelength ?2 to transmit data in a second, opposite direction over the link. The two wavelengths ?1 and ?2 differ by at least 10 nm. Each of the data streams transmitted over the optical link has a bandwidth of at least 2.5 Gbps. Further, each data stream has at least two logical streams embedded therein. A link multiplexer at each node of the network includes one or more link cards for coupling the link multiplexer to client devices, and one or more multiplexer units for coupling the link multiplexer to the optical links.

Abstract: In an electronic device, plural circuit boards are plugged into respective connectors, or sockets, in a common backplane circuit board. The backplane maintains the flat circuit boards in fixed relation to one another. Each circuit board is provided with a respective optical transmitter and/or receiver to allow for the transmission of (typically digital) information via a high speed carrier in a light beam through unobstructed free space between the circuit boards. The circuit boards may also be provided with optical splitters and/or combiners as well as apertures to permit light signals to pass through the board's substrate to allow for communication between plural circuit boards. The circuit boards may further include small lenses and/or opaque elements to provide an optical path having selected physical characteristics.

Abstract: A method and a system in which selected wavelengths of a wavelength division multiplexed (WDM) signal are modulated with multicast data for multicasting data services on an optical network. The WDM signal is received from a hub node of the optical network, such as a unidirectional ring network or a bi-directional ring network. A four-port wavelength crossbar switch (4WCS) selectably switches selected wavelengths from the optical network to a modulator loop. The modulator loop includes a multicast modulator that modulates the selected plurality of wavelengths with the multicast data. Each modulated wavelength is then switched back to the optical network by the 4WCS switch, and sent to a plurality of subscriber nodes of the optical network. This architecture allows a facility provider to be physically separated from a content provider, and affords the flexibility of selectively delivering multicast content to individual subscribers.

Abstract: A photonic switching device for switching without contention data in the form of optical packets includes a space switching matrix with a plurality of input ports and a plurality of output ports. A unit external to the space switching matrix includes a buffer memory common to all the output ports of the matrix. Each of the output ports provides access to the buffer memory via a space switching stage consisting of switches having a 1-to-2 switching function.

Abstract: One of optical packets x copied by an optical copying mechanism 11 is converted into an electric packet by an optic/electric converting mechanism 13. An address information extracting mechanism 14 extracts address information from a header of the packet converted into the electric packet. A control light generating mechanism 15 generates a control light based on the extracted address information. The other of the copied optical packets x is delayed by an optical delaying mechanism 12 for a predetermined time, and entered to a third nonlinear optical effect device 1b. The third nonlinear optical effect device 1b switches a route of the optical packet x based on the control light. The optical packet x is outputted through an optic/electric converting mechanism 1h0, a buffer 1i0, a multiplexing mechanism 1j, and an electric/optic converting mechanism 1k.

Abstract: The access node for optical networks with variable access wavelengths can be connected to user devices via respective first optical conductors and can be connected to the optical network via second optical conductors. The novel access node has light sources which emit at the wavelengths defined in the optical network. The light of the light sources can be modulated in the user devices. This prevents that in each case a light source which must be able to emit light of a different wavelength in a dynamic optical network or the wavelengths of which must be subsequently converted must be arranged in the individual user devices. In addition, it also prevents circuit boards leading to a high logistical expenditure having to be provided in the user devices. Accordingly, according to the invention, it is possible to construct the individual user devices without light sources. This considerably simplifies their construction and the method of use.

Abstract: A gateway exchange node according to a first embodiment of the present invention is disclosed. The gateway exchange node includes an exchange area network (XAN) xswitch. The gateway exchange node includes a wide area network (WAN) wavelength switch coupled to the XAN xswitch.

Abstract: A technique for interchanging wavelengths in a multi-wavelength system having W wavelength channels is disclosed. In one embodiment, the technique is realized by selectively directing a pair of adjacent frequency channels corresponding to a respective pair of adjacent wavelength channels based upon a routing algorithm. The frequencies of the selectively directed pair of adjacent frequency channels are then interchanged. The interchanged frequencies of the selectively directed pair of adjacent frequency channels are then selectively shifted based upon a binary representation of each interchanged frequency.

Abstract: An optical multiplexer and demultiplexer (mux-demux) (100) comprises a multimode waveguide (126) which communicates with first (122) and second (124) coupling waveguides. Multiplexed optical radiation comprising individual wavelength channels of appropriate wavelength introduced into the input waveguide is demultiplexed by means of modal dispersion and in-ter-modal interference with the multimode waveguide. The mux-demux consists of merely of waveguides and is therefore simple to fabricate and integrate with other components in integrated optical systems, and is capable of resolving channels having a small (˜1 nm) wavelength spacing. The mux-demux may be used without modification as a demultiplexer and remains of simple construction when scaled up to operate with many channels.

Abstract: A protection arrangement for an optical switching system includes protection switching for switch planes in the optical core and for ports in the tributary cards. For a multiple layer switch core protection is also provided between layers. A first layer is for switching optical channels. The protection switches used may be 1×N, 2×N or 3×N MEMS optical switches. The 1×N MEMS provides for protection switching. The 2×N MEMS provides protection switching and testing capability. The 3×N MEMS provides for protection switching, testing and backup of the protection switching. Application of these protection switches is shown in lambda plane switch cores, multiple layer switch cores and combined switch cores.

Abstract: A method is provided for seamless migration from static to agile optical networking at a network switching node in an optical transport network. The seamless method includes: providing an optical signal splitter at the input of thenetwork switching node, the signal splitter being adapted to receive an optical multiplexed signal having a plurality of data signals and at least one data signal being agile; providing an optical signal combiner at the output of the network switching node; and introducing a photonic cross-connect switch between the signal splitter and the signal combiner, where the photonic switch is operable to switch the agile data signals.

Abstract: A control system for an agile optical network uses constraint-based rules to minimize route validation computations required when the network is reconfigured. A hierarchical control structure facilitates admission control and insulates admission control from interaction with the physical layer of the network.

Abstract: An optical switching apparatus includes an optical switch having a plurality of input ports and output ports, optical amplifiers, monitor circuits, optical amplifiers monitor circuits, and a controller that controls the optical switch. The optical amplifiers are connected to the input ports of the optical switch. The monitor circuits are connected to the output ports of the optical switch. The controller selects one of the plurality of the monitor circuits based on predetermined rules to obtains the loss at the output ports and/or the differential loss between the channels of the optical switch. The controller further selects one of the optical amplifiers based on the configuration of the optical switch to compensate the loss and the differential loss among the different channels of the optical switch by pre-amplifying the optical signals before they reach the input ports of the optical switch.

Abstract: An optical switching apparatus includes an optical switch having a plurality of input ports and output ports, optical amplifiers, monitor circuits, optical amplifiers monitor circuits, and a controller that controls the optical switch. The optical amplifiers are connected to the input ports of the optical switch. The monitor circuits are connected to the output ports of the optical switch. The controller selects one of the plurality of the monitor circuits based on predetermined rules to obtains the loss at the output ports and/or the differential loss between the channels of the optical switch. The controller further selects one of the optical amplifiers based on the configuration of the optical switch to compensate the loss and the differential loss among the different channels of the optical switch by pre-amplifying the optical signals before they reach the input ports of the optical switch.

Abstract: Optical signals inputted to input ports are split in half by 1×2 optical splitters respectively and the resulting signals are inputted to the input terminals of an optical matrix switch. The optical matrix switch switches between the routes of the individual optical signals and outputs the signal at any of the output ports. This enables the optical signal from the same input port to be outputted at two different output ports, which makes it possible to effect “bridge” at the time of protection switching.

Abstract: Transparent wavelength division multiplexing systems and methods include an array of wavelength converters receiving n input signals and shifting the wavelength of each input signal by a different amount so that n different wavelengths result. Each of the wavelength converters shifts the wavelength of the input signal by a known amount. The resulting signals may be combined and transmitted over a fiber. A passive (or active) wavelength splitter may be used to recover the signals from the fiber, and deliver the signals directly to one or more network devices. Receivers in the receiving router or switch generally are not wavelength-specific, so the n optical signals need not be shifted back to a common wavelength prior to the router or switch.

Abstract: An optical filter comprises a multimode waveguide, and first and second coupling waveguides which communicate with the multimode waveguide at respective ends thereof. Filtering is achieved by the effect of self-imaging in the multimode waveguide. The filter further comprises one or more series of aperture within the multimode waveguide, the or each series being located at a longitudinal position within the multimode waveguide at which 1-to-N way intensity division of an input optical field occurs, the optical field being the lowest order transverse mode of the coupling waveguides. The (one or more) series of apertures reduces the transmission of the filter at wavelength other than those corresponding to transmission peaks of filter's transmission function, thus providing improved filtering performance compared to prior art optical filters based on self-imaging.

Abstract: An optical transport switching system having an all-optical switch that can be selectively configured to provide cross-connection and add/drop multiplexing functions. Optical circuit cards are provided in a chassis/bay, and connected by an optical backplane. The circuit cards may include access line interface cards, optical access ingress cards, transport ingress cards, transport egress cards, and optical access egress cards. An optical switching fabric provides selective optical coupling between the cards. The all-optical switch can be used in an optical network that allows external/access networks to access the optical network, including access networks that use Gigabit Ethernet or SONET signaling. Wavelength conversion is provided for non-compliant wavelengths of the access networks. A local area network enables control and monitoring of the cards by a local node manager.

Abstract: A wavelength Division Multiple Access (WDMA) free space broadcast technique for optical backplanes and interplanar communications for providing free space optical interconnects between multiple circuit cards in a computer system or networking device which is compatible with existing electrical backplanes. Current equipment can easily be upgraded in the field to take advantage of this new approach by simply replacing existing printed circuit boards, without requiring a complete redesign of the copper backplane.

Abstract: An integrated architecture called LOBS using enhanced/extended MPLS as a control plane and OBS as a switching paradigm that avoids optical/electrical/optical conversion of data at intermediate nodes is proposed. The structure of a LOBS node and the AP interface between an edge LOBS node and protocol data unit devices such as electronic LSR's are proposed, so are the structure of a LOBS control packet, burst assembly/disassembly methods, methods for fault detection/localization and recovering from lost bursts, and LOBS specific information for distribution using extended IGP protocols for traffic engineering.

Abstract: An optical packet exchange apparatus and an optical switch in which search for a connection pattern between an input unit devoid of a packet to be transmitted and an output unit devoid of a packet to be received is reduced to enable fast switch control even in cases wherein the number of channels of the exchange apparatus is increased or network speed is higher. A plurality of input units, a plurality of output units and an optical switch are provided. Each input unit includes an input buffer unit, a parallel/serial conversion unit, an electrical/optical conversion unit, and a dummy packet insertion unit for sending a dummy packet if there is no packet to be transmitted. Each output unit includes an exchange counterpart contention resolution unit for controlling the exchange counterpart, an optical/electrical conversion unit, a serial/parallel conversion unit, and a packet eliminating unit. The exchange counterpart contention resolution unit controls the packet eliminating unit to eliminate a dummy packet.

Abstract: A connector to an optical fiber comprises a prism, a ferrule and an aspheric lens. The prism includes a triangular wedge element having a first surface, a second surface and a base. The ferrule guides the optical fiber so as to contact the optical fiber with the first surface of the prism. The aspheric lens is integrated on the second surface, the integrated aspheric lens being positioned so that the prism serves to redirect a light beam at an angle relative to an axis of the optical source input through total internal reflection by utilizing the base of the triangle wedge element. The aspheric lens serves to collimate the redirected light beam or focus the light beam before being redirected. This arrangement may, for example, be used within a WDM system to multiplex and de-multiplex several wavelengths of light, using a “zig-zag” optical path configuration and thin film filters to separate the wavelengths.

Abstract: A switch for an optical transmission network using wavelength division multiplexing has p1 input ports receiving p1 wavelengths and first switching means for switching the p1 wavelengths to p2 output ports, q1 input ports receiving q1 bands of wavelengths and second switching means for switching the q1 bands to q2 output ports, r1 input ports receiving r1 groups of bands and third switching means for switching the r1 groups of bonds to r2 output ports. The three switching means consist of a single switching matrix adapted to couple any of the p1+q1+r1 input ports to any of the p2+q2+r2 output ports. This single-matrix architecture can switch all the granularities at the same time, which facilitates reconfiguration as a function of evolution of the traffic to be switched.

Abstract: The invention provides an optical multiplexing and demultiplexing device using a two-dimensional photonic crystal, in which miniaturization and higher integration thereof can be achieved; an optical communication apparatus; and an optical communication system. The optical multiplexing and demultiplexing device of the present invention includes a substrate; and a plurality of slab layers provided on the substrate. The slab layers each have a two-dimensional photonic crystal structure, in which low refractive index regions are periodically arranged. In addition, the slab layers have line defects, provided in part of the periodical arrangement so as to function as a waveguide, and at least point defects formed in the respective periodic arrangements, the point defects capturing light having a specific wavelength and introducing it to the line defects or capturing light having a specific wavelength from the line defects and radiating it.

Abstract: A method and apparatus is provided for reformatting or interleaving a WDM signal that includes a plurality of optical channels having a first bandwidth and a first channel spacing. The method begins by receiving the WDM signal and dividing it into first and second subsets of optical channels each having a second channel spacing. Next, the first subset of optical channels are divided into third and fourth subsets of optical channels each having a third channel spacing. In addition, the second subset of optical channels is divided into fifth and sixth subsets of optical channels each having a fourth channel spacing. The third and fifth subsets of optical channels are combined to generate a first output WDM signal, while the fourth and sixth subsets of optical channels are combined to generate a second output WDM signal.

Abstract: A laser device for medical treatment system, comprising at least a plurality of laser beam emitting sources, a laser beam multiplexing means for superimposing the laser beams emitted from the laser beam emitting sources, and a beam mixing means where the laser beams from the laser beam multiplexing means enter.

Abstract: The invention relates to an interleaver circuit (10, 10?) for interleaving optical signals, comprising a first and a second input port (12, 14), an output port (16), a first optical filter (18; 18?) that has a first filter function with periodic passbands (32, 34, 36) and is connected to the first input port (12), a second optical filter (20; 20?) that has a second filter function with periodic passbands (38, 40) and is connected to the second input port (14), and an optical interleaver (22). The latter comprises a multiplexing port (23) connected to the output port (16) and two de-multiplexing ports (24, 26) connected to the first input port (12) via the first optical filter (18; 18?) and the second optical filter (20; 20?), respectively. At least one optical filter (18, 20; 18?, 20?) is tunable such that the passband frequencies are collectively shiftable without altering the periodicity of the filter function.

Abstract: A first transmitting section frequency-multiplexes a data signal and a monitor signal, and then converts the resultant signal to an optical signal for output. A first receiving section converts the optical signal transmitted via a first optical transmission path and a wavelength demultiplexer into an electrical signal, and then extracts the monitor signal. A difference detector compares a monitor signal level with a predetermined reference level, and then outputs wavelength information to a second optical transmission path. Based on the wavelength information transmitted via the second optical transmission path, a first wavelength controller adjusts the wavelength of the optical signal for stabilization at a predetermined wavelength. Thus, it is possible to achieve a wavelength division multiplex transmission system capable of controlling the wavelength of the optical signal at low cost.

Abstract: A wavelength access server (WAS) architecture provides aggregation of traffic streams of diverse data communication protocols as well as provision of wavelength resources in an optical transport network. The WAS provides functions such as service traffic adaptation, traffic aggregation and segmentation, traffic classification, optical inter-working and system management. In particular, system management includes aspects such as signaling, connection management, resource co-ordination, protection prioritization and access policy management.

Abstract: An electromagnetic matched filter based multiple access communications system having a source of modulated pulses from a digital data stream; an initial filter which shapes the incoming modulated pulse into a desired pulse for transmission across the communication medium; a second filter, identical to the initial filter, which is matched to the pulse which exit the communication medium, a detector which converts the modulated pulse stream into the original digital data stream, and signals which are designed with specific mathematical properties which make the system efficient and minimizes crosstalk between channels. The signals decay rapidly from the central lobe at a higher than 1/x rate and the zero points of the autocorrelation function having high order multiplicities. The type of system allows multiplexing of multiple data streams with much greater flexibility, robustness, and density.