Abstract: A method for scheduling resources for a Wavelength Division Multiplexed, WDM, Passive Optical Network, PON. The WDM PON comprises a central hub (201) and a plurality of remote Optical Network Terminals, ONTs, (220) handling different types of communications traffic. The method (450) comprises receiving (452) a notification message from the plurality of remote Optical Network Terminals, ONTs, indicating a loading status of the ONT, and allocating (454) one or more slots to a plurality of the ONTs based on the received notification messages from the ONTs, wherein the plurality of ONTs (220) handle different types of communications traffic. The slots (301) are allocated based on the received notification messages as a time slot which is time division multiplexed with further time slots, and the slots are further allocated based on the received notification messages as an optical wavelength of a plurality of optical wavelengths of the WDM PON.

Abstract: A network or system in which a hub or primary node may communicate with a plurality of leaf or secondary nodes. The hub node may operate or have a capacity greater than that of the leaf nodes. Accordingly, relatively inexpensive leaf nodes may be deployed to receive data carrying optical signals from, and supply data carrying optical signals to, the hub node. One or more connections may couple each leaf node to the hub node, whereby each connection may include one or more spans or segments of optical fibers, optical amplifiers, optical splitters/combiners, and optical add/drop multiplexer, for example. Optical subcarriers may be transmitted over such connections, each carrying a data stream. The subcarriers may be generated by a combination of a laser and a modulator, such that multiple lasers and modulators are not required, and costs may be reduced.

Abstract: A transmitter for a quantum communication system, comprising: a photon source unit comprising a photon source; a first intensity modulator, configured to receive an input light pulse from the photon source unit, the first intensity modulator comprising: a first element, configured to split the input light pulse into two components; a phase modulator, configured to apply a phase shift between the two components; and a second element, configured to interfere the two components; wherein at least one of the first element and the second element is asymmetric.

Abstract: A packet switching system for a packet transfer network, the system having an architecture including a plurality of line cards, each including an ingress path pipeline, with processing elements, and an egress buffer, and an electro-optical In/Out (IO) interconnect coupling the line cards to one another in a full mesh connectivity, in the absence of a switch fabric, wherein the ingress path pipeline of each line card is coupled by means of the electro-optical IO interconnect to the egress buffer of each of the plurality of line cards.

Abstract: Methods and systems for combining signals include modulating data onto a first signal at a first frequency and wavelength; modulating data onto a second signal at a second wavelength using a modulation scheme that produces spectral components at the first frequency; filtering the second signal using an optical filter to suppress spectral components that would cause interference to the first signal; and combining the first signal and the second signal onto a transmission medium.

Abstract: A user equipment (UE) device includes a VLC receiver including a photodiode and a radio receiver. The UE device supports a plurality of alternative technologies, communications protocols, and/or frequencies. During a first mode of operation, e.g., a discovery mode, a low reverse bias voltage value is applied to the photodiode. The low reverse bias voltage is adequate to support the recovery of small amounts of communicated information, and the power consumed by the battery of the UE device is relatively low. During discovery, information communicated includes, e.g., a light transmitter ID, an access point ID, services available at the access point, configuration information for a light receiver and/or for an auxiliary radio receiver. During a second mode of operation, e.g., a data traffic mode, the reverse bias voltage applied to the photodiode is set to a high reverse bias voltage to support higher data rate using VLC.

Abstract: Methods and systems for combining signals include modulating data onto a first signal at a first frequency and wavelength; modulating data onto a second signal at a second wavelength using a modulation scheme that produces spectral components at the first frequency; filtering the second signal using an optical filter to suppress spectral components that would cause interference to the first signal; and combining the first signal and the second signal onto a transmission medium.

Abstract: Systems and methods are provided for network communication using wireless base stations and an optical orthogonal frequency division multiple access (OFDMA) signal generated on an optical wavelength, with the optical OFDMA signal being composed of a plurality of OFDMA subcarriers. A multi-level modulator modulates each of the plurality of OFDMA subcarriers. A single optical wavelength propagates each of the plurality of OFDMA subcarriers to different base stations; a passive optical splitter delivers the optical OFDMA signal to different base stations; and an OFDMA subcarrier de-multiplexer delivers and extracts traffic for each of the base stations in an electronic-domain, wherein the extracted traffic is remodulated in a wireless signal format. Antennas at each of the base stations transmit wireless signals, and the wireless signals are recovered and processed from the base stations.

Abstract: An optical network includes a multidimensional coder and modulator for handling multiple-in-multiple-out MIMO spatial lightpath properties and content of any specific supercarrier, a spatial mode multiplexer responsive to orthogonal frequency division multiplexing OFDM transmissions and the multidimensional coder, a spatial-spectral routing node coupled over a fiber link to the spatial mode multiplexer for performing switching granularity by a spatial mode reconnection, a multidimensional decoder and demodulator; and a spatial mode demultiplexer coupled over a fiber link to the spatial-spectral routing node and responsive to the multidimensional decoder and demodulator.

Abstract: A method implemented in a Fiber Coaxial Unit (FCU) comprising receiving a plurality of Ethernet Passive Optical Network (EPON) report messages from a plurality of Coaxial Network Units (CNUs) across a coaxial network, receiving an EPON gate message comprising Time Quanta (TQ) information indicating an upstream transmission time grant for the FCU across the optical network, translating the TQ based upstream transmission time grants to OFDM resource block grants in a time domain and in a frequency domain across the coaxial network for each CNU based on the configurable constants, and transmitting an EPON over Coaxial (EPoC) gate message to each CNU, wherein each EPoC gate message comprises a CNU profile indicating the Orthogonal Frequency-Division Multiplexing (OFDM) resource block grants for the an associated CNU and a start time.

Abstract: The present invention discloses a multiple star wavelength division multiplexing passive optical network system using a wavelength assignment method. In a multiple star wavelength division multiplexing passive optical network system using a wavelength assignment method according to the present invention, only one WDM-PON system can provide services for a plurality of subscribers who is distributed in a wide range of area through multiple starring, by setting one or more band for transmitting up-stream signals as an up-stream basic band and one or more band for transmitting down-stream signals as a down stream basic band, respectively, and by dividing each of the up-stream basic band and the down stream basic band into a plurality of wavelength sub-bands and assigning the divided sub-bands to different areas using a wavelength division multiplexer/de-multiplexer which splits a band into two or more sub-bands.

Abstract: In general, a wavelength division multiplexed (WDM) communication system may use wavelength selective switching to simultaneously pre-filter and combine groups of channel wavelengths with orthogonal polarizations to provide a pre-filtered, pair-wise orthogonal aggregate WDM optical signal. An orthogonally-combining wavelength selective switch (WSS) multiplexer may route channel wavelengths individually from different sets of channels to a common output. The orthogonally-combining WSS multiplexer may also provide substantially orthogonal polarizations for the wavelengths in the different sets of channels. The different sets of channels may include odd channels and even channels.

Abstract: An apparatus comprising a path computation element (PCE) coupled to a path computation client (PCC) and configured to perform a path computation using port wavelength restriction information for a network element (NE), wherein the port wavelength restriction information is encoded and received in a port wavelength restriction Type-Length-Value (TLV) that comprises a matrix identifier (ID), a restriction type, and the port wavelength restriction information. Also disclosed is a network component comprising at least one processor coupled to a memory and configured to receive a port wavelength restriction information TLV that corresponds to a NE, and obtain a restriction type and port wavelength restriction information based on the restriction type from the port wavelength restriction TLV, and use the port wavelength restriction information to calculate a path for the NE.

Abstract: Apparatus and methods for providing content to devices in a content distribution network. In one embodiment, a hybrid fiber/coax network provides optical signals to an amplification and combination node, the signals which are converted to radio frequency (RF) signals and transmitted to a series of cascading amplification and combination apparatus. The converted signals are combined with legacy RF signals at the combination apparatus, and distributed further downstream to serviced premises as well as other portions of the network cascade. Time division techniques are used to mitigate interference between the various amplification and combination nodes within the cascade. The programmable time division devices allow for rapid spectrum reallocation, and for insertion of different content at each different node of the network.

Abstract: An optical data bus transceiver (110), optical data bus system (100) and method (300) employ a disambiguation signal to resolve bit ambiguities in a summation signal on an optical data bus (104). The optical data bus transceiver includes a transmitter (112) connected to the optical bus and configured, in conjunction with another transmitter (112?, 120), to produce on the optical bus the summation signal during a first interval and the disambiguation signal during a second interval. The optical data bus transceiver further includes a receiver (114) configured to receive (310) the summation signal. The summation signal includes a summation of separate data signals from each of the transceiver transmitter (112) and the other transmitter (112?, 120). The disambiguation signal includes information to resolve bit ambiguities in the summation signal. A bit ambiguity results from a summation of data bits in each of the respective data signals during a symbol period of the first interval.

Abstract: A converged passive optical network (CPON) and a data transmission method are disclosed. The CPON is a combination of a time division multiple access-passive optical network (TDMA-PON) and an orthogonal frequency division multiple access-passive optical network (OFDMA-PON) and is able to dynamically controlling a bandwidth for upstream signal transmission through allocation of multiple subcarriers to each single optical network unit (ONU).

Abstract: A Passive Optical Network (PON) multicast management method includes: an Optical Line Terminal (OLT) performs multicast control according to multicast control information, and generates a corresponding multicast downstream command; the OLT sends the multicast downstream command to an Optical Network Unit (ONU); and the ONU resolves the multicast downstream command, and performs multicast control according to the multicast downstream command. Accordingly, a PON multicast communication system, an OLT, and an ONU are disclosed. Through the multicast control mechanism introduced into the PON system, the PON multicast functions are enhanced, and the same data destined for multiple ONUs is prevented from being sent repeatedly in the network, and thus the network bandwidth resources are saved.

Abstract: An apparatus comprising a path computation element (PCE) coupled to a path computation client (PCC) and configured to perform a path computation using port wavelength restriction information for a network element (NE), wherein the port wavelength restriction information is encoded and received in a port wavelength restriction Type-Length-Value (TLV) that comprises a matrix identifier (ID), a restriction type, and the port wavelength restriction information. Also disclosed is a network component comprising at least one processor coupled to a memory and configured to receive a port wavelength restriction information TLV that corresponds to a NE, and obtain a restriction type and port wavelength restriction information based on the restriction type from the port wavelength restriction TLV, and use the port wavelength restriction information to calculate a path for the NE.

Abstract: A transmitting apparatus includes a plurality of code spreaders different in spreading code, a reception processing unit that selectively distributes transmission data to the plurality of code spreaders, a plurality of optical transmitters each of which that transmit a code-spread signal to an optical fiber as a CDMA optical signal of a carrier wavelength different from that of the other optical transmitters, and a signal multiplexing unit that selectively supplies outputs of the plurality of code spreaders to the plurality of optical transmitters. A receiving apparatus includes an optical receiver that receives a wavelength-division-multiplexed CDMA optical signal from the optical fiber, and a plurality of despreaders connected to the optical receiver and different in spreading code, wherein each of the despreaders reproduces a CDMA signal corresponding to its spreading code from an output signal of the optical receiver.

Abstract: A wavelength division multiplexed (WDM) optical system generally includes multi-channel transmitters that transmit optical signals on multiple channel wavelengths in the WDM system. The output of the multi-channel transmitters is filtered to select a unique channel wavelength associated with each of the respective transmitters for multiplexing and transmission in the WDM optical system. One embodiment of a multi-channel transmitter includes a full-spectrum Fabry-Perot (FP) laser that emits light across a range of wavelengths including all of the system channel wavelengths. Another embodiment of a multi-channel transmitter includes a broadly-tunable FP laser that is tunable to emit light across different ranges of wavelengths including subsets of the system channel wavelengths. The WDM optical system may include an arrayed waveguide grating (AWG) for filtering and multiplexing the optical signals output from the transmitters.

Abstract: A protected light source for generating seed light for at least two wavelength division multiplexed passive optical networks (WDM-PONs). The protected light source includes an optical coupler having N?2 input ports and M?2 output ports, each output port being optically connected to supply seed light to a respective set of one or more WDM-PONs. A respective multi-wavelength light source (MWLS) is optically coupled to supply seed light to each input port of the optical coupler. A controller unit controls operation of each multi-wavelength light source (MWLS).

Abstract: Various embodiments of the present invention are directed to systems and methods for all optical distributed arbitration for computer system components (1801-1804) communicatively coupled via a photonic interconnect in a computer system device. The embodiments of the optical arbitration in the computer system provides arbitration schemes with fixed priority (2000) and non-fixed priority (1830, 2200). The non-fixed priority scheme embodiments can provide fairness in arbitration. In some embodiments, delivery of light power and arbitration are combined (1830, 2001).

Abstract: A signal processing method, device, and system in a passive optical network are provided. The signal processing method in the passive optical network includes: performing baseband encoding processing on a received service signal; modulating the service signal after baseband encoding processing onto allocated Orthogonal Frequency Division Multiple Access subcarriers through an Orthogonal Frequency Division Multiplexing modulation manner; performing digital/analog conversion on the modulated OFDMA subcarriers to obtain an electric domain Orthogonal Frequency Division Multiple Access signal; modulating the electric domain Orthogonal Frequency Division Multiple Access signal to an uplink optical signal to obtain an optical domain Orthogonal Frequency Division Multiple Access signal; and transmitting the optical domain Orthogonal Frequency Division Multiple Access signal.

Abstract: A timing interface module with daughter timing reference modules. The timing modules are provided in a rack platform to eliminate routing problems and which is compliant with all relevant industry standards. The timing reference module includes a face plate having first and second substantially rectangular openings, the face plate further comprising mounting slots for receiving mounting hardware therein and first and second timing modules, the first and second timing modules disposed within the first and second substantially rectangular openings. The first and second timing modules provide timing terminations for timing reference signals for network elements of a synchronized optical network.

Abstract: The invention relates in general to a method, an apparatus and a unit for operating a Wavelength Division Multiplexing Access Network 25, and in particular to unbundling wavelengths in the network 25. Embodiments of the invention disclose monitoring a plurality of wavelengths of the Wavelength Division Multiplexing Access Network 25 to determine at least one available wavelength that is free for use. The transmitter then automatically transmits data to at least one user device 22 via at least one available wavelength.

Abstract: A system and method for dynamically allocating sub-carriers between the nodes of an optical OFDMA ring network or an OFDMA passive optical network. A carrier allocation system assigns sub-carriers according to a utility function based on real-time measurements of arrival data rates and queue length variance.

Abstract: In accordance with the teachings of the present invention, a system and method for extending reach in a passive optical network (PON) is provided. In a particular embodiment, a method for extending reach in a PON includes transmitting traffic at a first wavelength from a transmitter at a first optical network unit (ONU) in a PON and transmitting traffic at a second wavelength from a transmitter at a second ONU in the PON. The method also includes receiving the traffic in the first wavelength at a first input port of a multiplexer at a distribution node in the PON and receiving the traffic in the second wavelength at a second input port of the multiplexer at the distribution node. The method further includes forwarding the traffic in the first wavelength and the traffic in the second wavelength to an optical line terminal (OLT) in the PON.

Abstract: A protected light source for generating seed light for at least two wavelength division multiplexed passive optical networks (WDM-PONs). The protected light source includes an optical coupler having N?2 input ports and M?2 output ports, each output port being optically connected to supply seed light to a respective set of one or more WDM-PONs. A respective multi-wavelength light source (MWLS) is optically coupled to supply seed light to each input port of the optical coupler. A controller unit controls operation of each multi-wavelength light source (MWLS).

Abstract: In general, wavelength division multiplexed (WDM) communication systems may use wavelength selective switching to aggregate and/or deaggregate groups or bands of channel wavelengths. A wavelength selective switch (WSS) band aggregator may combine a plurality of channel band aggregate optical signals to produce a combined aggregate optical signal (i.e., a transmitted WDM or DWDM signal). The WSS band aggregator may also combine one or more spectral portions of broadband noise with the bands of channel wavelengths such that the spectral portion(s) of the broadband noise occupies unutilized channels in the combined aggregate optical signal. A WSS band deaggregator may separate a combined aggregate optical signal (i.e., a received WDM or DWDM signal) to produce a plurality of channel band aggregate optical signals.

Abstract: Provided are a network node which has a wavelength switching cross-connection function and can thus interconnect paths of a wavelength-division-multiplexed optical signal and convert wavelengths, and an operating method of the network node. Accordingly, it is possible to provide a multi-degree cross-connection system having a simple structure at lower cost by allowing transmission of optical signals supposed not to be added/dropped at a network node without converting them into electrical signals and performing O/E conversion or E/O conversion only on optical signals supposed to be added/dropped at a network node. In addition, it is possible to increase the expandability of networks by regenerating degraded signals and which can effectively utilize bandwidths by grooming low-speed electrical digital hierarchy signals and transmitting them as high-speed optical signals.

Abstract: Techniques are disclosed for providing bi-directional data services involving a plurality of wavelengths. The data services may be hybrid in nature, including both digital and analog data signals. The techniques may be implemented, for instance, in an optical module, and allow one or more wavelengths to pass-through while other wavelengths are terminated or otherwise diverted. In one example embodiment, the techniques are embodied in a quad-port optical module having two input/output (I/O) ports and pass-through capability for at least one of the wavelengths, add capability for at least one wavelength, and drop capability for at least one wavelength. The module may further include transmit and/or receive capability for one or more signal types. The module can be operatively coupled with a bidi device or other suitable transceiver, to provide modular transmit-receive capability for a desired signal type.

Abstract: A tunable filter is provided.

Abstract: This invention allows measuring the spectral state of an object more accurately even at low luminance, and implementing high-precision focus detection. A photometry apparatus includes a diffusing optical member which is inserted in the optical path of a photographing lens and has a diffusing surface, and a light unit which receives diffused light having passed through the diffusing surface, and has a first light receiving portion, and a second light receiving portion whose receivable light energy is smaller than that of the first light receiving portion. The first and second light receiving portions are so arranged as to make the parallax of the second light receiving portion with respect to the optical axis of the photographing lens smaller than that of the first light receiving portion.

Abstract: In one aspect, a method for congestion avoidance in a passive optical network having an optical line terminal communicatively connected to a plurality of optical network termination devices is provided. A dynamic bandwidth allocation information is periodically requested from the optical network termination device and the optical line terminator receives the response to the request. An adjusted bandwidth allocation for the optical network termination device is determined by the optical line terminator. The optical line terminator determines a packet-drop command to be taken at the optical network termination device. The adjusted bandwidth allocation and the packet-drop command are sent to the optical network termination device.

Abstract: An optical transmitting circuit (2) modulates multimode oscillation light using an information signal, subjects at least one oscillation-mode light beam of the multimode oscillation light to a predetermined operation, and outputting the result to an optical transmission channel. An optical receiving circuit (8) receives an optical signal transmitted through the optical transmission channel, subjects the received optical signal to an operation reverse to the predetermined operation to recover an optical signal as it was before being subjected to the predetermined operation, and converting the recovered optical signal into an electrical signal, thereby reproducing the information signal.

Abstract: A system and a method for quantum key distribution between a transmitter and a receiver over wavelength division multiplexing (WDM) link are disclosed. The method includes providing one or more quantum channels and one or more conventional channels over the WDM link; assigning a different wavelength to each of the one or more quantum channels and each of the one or more conventional channels; transmitting single photon signals on each of the one or more quantum channels; and transmitting data on each of the one or more conventional channels. The data comprises either conventional data or trigger signals for synchronizing the transmission of the single photon signals on the quantum channels. All channels have wavelengths around 1550 nm. The WDM link can be a 3-channel WDM link comprising two quantum channels for transmitting single photon signals and one conventional channel for transmitting conventional data or triggering signals.

Abstract: A multiservice private network and interface modules (M1-M5). Each of said modules is dedicated to interfacing a specific terminal equipment (T1-T4, GTW; 310-380) in the multiservice private network. The interface modules (M1-M5) are connected to the terminal equipment on a one-to-one basis. Each interface module (M1-M5) is configured to send and/or receive data in a format adapted to the terminal equipment to which it is connected, at a specific wavelength, in order to interconnect, via said private network, at least two mutually compatible terminal equipments among all the terminal equipments. This arrangement is typically applicable in particular to interconnecting, via a common network, heterogeneous different terminal equipments, so that the mutually compatible terminals communicate directly with one another without interfering with communication between other terminals of a different type.

Abstract: A passive optical network (PON) device, system and method include an optical line terminal (OLT) receiver configured to receive multiple signals at different wavelengths simultaneously and enable multiple transmitters to operate at the same time during one upstream time slot. The optical line terminal employs Orthogonal Frequency Division Multiple Access (OFDMA) to transparently support a plurality of applications and enable dynamic bandwidth allocation among these applications where the bandwidth is allocated in two dimensional frequency and time space.

Abstract: An apparatus and methods for encoding and decoding data are disclosed. The method for transmitting and receiving data allows for coding and decoding each bit of data with a different code. The transmitter and receiver devices allow encoding and decoding, respectively, each bit of data with different a code.

Abstract: Systems, networks, and methods of providing an Internet protocol routing network are disclosed. One Internet protocol routing network includes: a number of local subnet routers, where the routers are Internet protocol (IP) enabled; a single mode optical fiber cable, where the local subnet routers are coupled to the optical fiber cable; and one or more optical code division multiple access (OCDMA) encoder/decoder coupled to the optical fiber cable, where a number of channels associated with the local subnet routers are assigned an OCDMA signature code.

Abstract: An optical transmitting circuit (2) modulates multimode oscillation light using an information signal, subjects at least one oscillation-mode light beam of the multimode oscillation light to a predetermined operation, and outputting the result to an optical transmission channel. An optical receiving circuit (8) receives an optical signal transmitted through the optical transmission channel, subjects the received optical signal to an operation reverse to the predetermined operation to recover an optical signal as it was before being subjected to the predetermined operation, and converting the recovered optical signal into an electrical signal, thereby reproducing the information signal.

Abstract: An optical access network system capable of transmitting and receiving high-speed signals and which allows the number of subscribers to be increased without increasing the number of wavelengths used is provided. An optical line terminal and an optical network unit are joined via an optical fiber transmitting line, a star coupler, and a plurality of branching optical fiber transmitting lines. The optical line terminal and optical network unit are constituted comprising an optical processing section and an electrical processing section. The optical processing section comprises a light-emitting element and a light-receiving element.

Abstract: A wavelength-division-multiplexed based photonic burst switched (PBS) network, which includes edge and switching nodes, optically communicate information formatted into PBS control and data burst frames. Each PBS data burst frame is associated with a PBS control burst frame. A PBS burst frame includes a PBS burst header and burst payload having fields to indicate whether: (a) the PBS burst frame is a PBS control burst; (b) the control burst is transmitted on a wavelength different from that of the associated PBS data burst; and (c) the PBS burst frame has a label for use in a generalized multi-protocol label swapping (GMPLS)-based control system. The PBS burst payload frame includes fields to indicate (a) specific PBS payload information; (b) PBS data payload; and (c) an optional PBS payload frame check sequence (FCS) for error detection.

Abstract: A demultiplexer and a method of demultiplexing a multiplex of spatially separable multiple wavelength streams, where an incoming multiplex of multiple wavelength streams is separated into a first stream of wavelengths and a second stream of wavelengths according to at least one predetermined separation criterion. The first stream and the second stream are respectively input into a first and a second input port of a multi-input port, multi-output port frequency demultiplexer where the first stream and the second stream are separated into a first group of single wavelengths and a second group of single wavelengths respectively. The first group of single wavelengths is coupled to respective output ports and the second group of single wavelengths are coupled to respective output ports.

Abstract: An optical communications circuit has a communications light signal source and a heat pump coupled to cool the signal source. A controller monitors a current and a temperature of the signal source, and regulates the temperature. The controller updates a heat pump control limit parameter for the heat pump, based on the monitored current. Other embodiments are also described and claimed.

Abstract: A system and a method for quantum key distribution over a multi-user wavelength division multiplexing (WDM) network are disclosed. The system comprises a tunable or multi-wavelength transmitter; a plurality of receivers, each assigned a receiving-wavelength; and a multi-user WDM network linking the transmitter to the receivers. The transmitter can select a receiver among the receivers to be communicated therewith and transmit quantum signals to the selected receiver over the WDM network. The quantum signals are at a wavelength equal to a receiving-wavelength of the receiver. Therefore the WDM network allows quantum signals to be communicated between the transmitter and the receivers by wavelength routing.

Abstract: An optical network system is disclosed by which flexible wavelength path setting can be performed in accordance with tree-shaped and star-shaped network topology. A central node includes a multiplexing section for multiplexing optical signals transmitted from user nodes and inputted thereto, and a central node side branching section for branching the optical signal multiplexed by the multiplexing section and supplying the branched optical signals to the user nodes. Each of the user nodes includes a transmission section capable of outputting an optical signal to which transmission wavelengths different from those of the other user nodes are set, and a reception section for extracting selected optical wavelength components from the branched light supplied thereto from the central node side branching section and extracting optical signals from the extracted optical wavelength components.

Abstract: A laser beam multiplexer capable of easily multiplexing a plurality of laser beams is provided. A laser beam multiplexer includes a multiplexing element having a hollow portion with a sectional elliptical shape, in which the multiplexing element includes: a plurality of light-incident apertures guiding laser beams from outside toward one of two focal points of the hollow portion, a reflective layer arranged on a wall surface of the hollow portion, and multiplexing a plurality of incident laser beams while reflecting the plurality of laser beams, and a light-emitting aperture guiding laser beams multiplexed by the reflective layer toward outside.

Abstract: A method for integrating an Optical Service Channel (OSC) with a Quantum Key Distribution (QKD) channel across a DWDM network having a single mode optical fiber is provided. An optical signal is received. An OSC is coupled with the optical signal. A QKD channel is integrated with the OSC on the single mode optical fiber.

Abstract: An optical network system is disclosed by which flexible wavelength path setting can be performed in accordance with tree-shaped and star-shaped network topology. A central node includes a multiplexing section for multiplexing optical signals transmitted from user nodes and inputted thereto, and a central node side branching section for branching the optical signal multiplexed by the multiplexing section and supplying the branched optical signals to the user nodes. Each of the user nodes includes a transmission section capable of outputting an optical signal to which transmission wavelengths different from those of the other user nodes are set, and a reception section for extracting selected optical wavelength components from the branched light supplied thereto from the central node side branching section and extracting optical signals from the extracted optical wavelength components.