Abstract: A demodulator comprises an input splitter, optical device sets, and couplers. The input splitter splits an input signal comprising symbols to yield a number of signals. A first optical device set directs a signal of along a first path. A second optical device set directs another signal along a second path to yield a delayed signal. At least a portion of the second path is in free space. A path length difference between the first path and the second path introduces a symbol delay between the first signal and the second signal. A coupler receives a portion of the signal and a portion of the delayed signal to generate interference, where the interference indicates a phase shift between a phase corresponding to a symbol and a successive phase corresponding to a successive symbol.

Abstract: An optical network system enabling confirmation of connection and tracking of wavelength paths at a high speed and a low cost without introducing any special hardware by having a wavelength path monitoring unit in an NMS give temporary change of optical power through a change generating unit to an optical signal S from an optical transmitting/receiving node, by having a change detecting unit confirm that this change of optical power has propagated through an optical transmission line and appeared at each node on the way, and confirming connections and monitoring the wavelength path while confirming the presence of the change.

Abstract: Monitoring a demodulator includes repeating the following for each demodulating module of one or more demodulating modules of a demodulator: receiving a first signal and a second signal from a demodulating module; introducing a relative delay between the first signal and the second signal; and asynchronously sampling the first signal and the second signal to yield samples. Image data representing the samples associated with the demodulating modules is generated. The image data indicates one or more mismatches of the demodulator.

Abstract: A demodulator includes one or more modules operable to receive an input signal comprising symbols. A module receives a main signal comprising at least a portion of the input signal and splits the main signal to yield a branching signal and a remaining main signal. The branching signal travels along a first path, and the remaining main signal travels along a second path. The second path introduces a delay with respect to the first path. If there is a next module, the module sends a first portion of the remaining main signal to a next module as a main signal for the next module. The module combines the branching signal and at least a second portion of the remaining main signal to generate interference. The interference indicates a phase shift between a phase corresponding to a symbol and a successive phase corresponding to a successive symbol.

Abstract: A gas treatment apparatus for treating a gas by bringing the gas into contact with a treatment liquid. The gas treatment apparatus includes a gas-liquid contact chamber for a gas-liquid contact of the gas with the treatment liquid, a storage chamber, located over the gas-liquid contact chamber, for storing the treatment liquid, and a treatment liquid supplying unit for supplying the treatment liquid stored in the storage chamber to an inside of the gas-liquid contact chamber with a gravity-drop.

Abstract: A method includes transmitting, at a first wavelength, a first configuration message on the PON including a first transmitter interface number and transmitting, at a second wavelength, a second configuration message on the PON including a second transmitter interface number. The method further includes receiving a configuration response message from a first set of ONUs that comprises the first transmitter interface number and from a second set of ONUs that comprises the second transmitter interface, associating the first set of ONUs with the first wavelength and the second set of ONUs with the second wavelength, and transmitting downstream traffic destined for any ONU in the first set of ONUs at the first wavelength and transmitting downstream traffic for any ONU in the second set of ONUs at the second wavelength.

Abstract: In one embodiment, a method for providing wireless communications utilizing a passive optical network (PON) is disclosed. The method includes receiving, at a PON, downstream packets from a base station destined for a mobile station, and transmitting the downstream packets to wireless transceivers associated with PON. The method also includes receiving, at the first wireless transceiver communicatively coupled to a first optical network terminal (ONT), the downstream packets from the first ONT and transmitting a first wireless signal comprising the downstream packets to a first cell. The method also includes receiving, at a second wireless transceiver communicatively coupled to a second ONT, the downstream packets from the second ONT and transmitting a second wireless signal comprising the downstream packets to a second cell.

Abstract: Selecting a wavelength and a route includes facilitating communication through routes among nodes. Each route is associated with a plurality of wavelengths and comprises one or more segments that couple one node to another node. A polarization mode dispersion value is determined for each wavelength of each route to yield polarization mode dispersion values for each route. A wavelength and a route are selected according to the polarization mode dispersion values.

Abstract: In the optical network system, light input to any of the optical input ports of the optical coupler is converted into light at another wavelength via a variable-wavelength optical receiver and an optical sender, and is then reinput to the optical coupler. This arrangement makes it possible to realize a full-mesh optical network system with a simple construction at low costs.

Abstract: Monitoring a bias point of an optical modulator includes receiving an optical signal modulated by the optical modulator. Photons of the optical signal are received at a photon reactive material operable to produce a reaction in response to the arrival of a predetermined number of photons. Reactions are produced in response to the arrival of the photons of the optical signal. Feedback is generated in response to the reactions. The feedback reflects the waveform of the optical signal, and indicates one or more bias points of the optical modulator.

Abstract: In accordance with the teachings of the present invention, a hybrid passive optical network using shared wavelengths is provided. In a particular embodiment, a system for communicating optical signals over a network includes an upstream terminal. The upstream terminal includes a signal source operable to transmit a downstream signal comprising at least traffic in a first wavelength and traffic in a second wavelength. The upstream terminal is operable to receive upstream traffic in a third wavelength, wherein the third wavelength is shared by a first plurality of downstream terminals and a second plurality of downstream terminals. The system also includes a distribution node comprising a wavelength router. The wavelength router is operable to receive the downstream signal, route the traffic in the first wavelength to the first plurality of downstream terminals, and route the traffic in the second wavelength to the second plurality of downstream terminals.

Abstract: Monitoring a bias point of an optical modulator includes receiving an optical signal modulated by the optical modulator. Photons of the optical signal are received at a photon reactive material operable to produce a reaction in response to the arrival of a predetermined number of photons. Reactions are produced in response to the arrival of the photons of the optical signal. Feedback is generated in response to the reactions. The feedback reflects the waveform of the optical signal, and indicates one or more bias points of the optical modulator.

Abstract: In accordance with the teachings of the present invention, distribution components for a wavelength-sharing network are provided. In a particular embodiment, a distribution node for an optical network includes a first distributor operable to receive a first downstream signal comprising at least traffic in a first wavelength and traffic in a second wavelength from an upstream terminal, route the traffic in the first wavelength to a first plurality of downstream terminals, and route the traffic in the second wavelength to a second plurality of downstream terminals. A second distributor is operable to receive a second downstream signal comprising at least traffic in a third wavelength, and forward the traffic in the third wavelength to at least the first plurality of downstream terminals.

Abstract: A method for communicating optical traffic includes adding optical traffic to an optical ring comprising a plurality of nodes and communicating the optical traffic on the optical ring. The optical traffic comprises a plurality of virtual wavebands which comprise a first virtual waveband of traffic comprising a first number of wavelengths and a second virtual waveband of traffic comprising a second number of wavelengths. The second number is different from the first number. The method also includes dropping the first virtual waveband of traffic at a first node of the plurality of nodes and dropping the second virtual waveband of traffic at a second node of the plurality of nodes.

Abstract: An object of the invention is to provide a wavelength allocation method of signal light, which is capable of consecutively allocating signal lights efficiently on wavelength grids, while suppressing degradation in transmission characteristic due to the generation of four-wave mixed light in an optical transmission path. To this end, according to the wavelength allocation method of signal light, the consecutive allocation wavelength number of signal lights to be allocated consecutively on the wavelength grids, is set to different values according to wavelength bands, based on wavelength dependence of a generation amount of four-wave mixed light on the optical transmission path, and the signal lights are allocated consecutively on the wavelength grids in accordance with this consecutive allocation wavelength number, but the signal light is not allocated on at bas one wavelength grid adjacent to the wavelength grids on which a group or signal light are allocated consecutively.

Abstract: An optical transmission system that alleviates waveform distortions due to nonlinear effects in fibers. A transmitter sends WDM signals to a receiver over a dispersion-managed optical transmission line with in-line optical repeaters. The transmission line is divided into a plurality of dispersion compensation intervals each composed of a main segment and a compensation segment. Chromatic dispersion is managed such that the dispersion compensation intervals have a non-zero net dispersion at every boundary point between them, or such that the number of zero-dispersion boundary points is reduced. The main segment is a series of repeater sections with negative dispersion, while the compensation segment is a single repeater section with positive dispersion.

Abstract: In accordance with the teachings of the present invention, a system and method for managing communication in a hybrid passive optical network (HPON) is provided. In a particular embodiment, the method includes transmitting, at a first wavelength, a first configuration message on the HPON. The method also includes receiving at one or more of a plurality of receivers at an optical line terminal (OLT) one or more configuration response messages from one or more optical network units (ONUs) in a first set of ONUs. The method further includes, based on the configuration response messages from the first set of ONUs, associating, in a database, each ONU in the first set of ONUs with the first wavelength and with the receiver receiving the configuration response message from the ONU. The method also includes, after transmitting the first configuration message, transmitting, at a second wavelength, a second configuration message on the HPON.

Abstract: An optical transmission system that alleviates waveform distortions due to nonlinear effects in fibers. A transmitter sends WDM signals to a receiver over a dispersion-managed optical transmission line with in-line optical repeaters. The transmission line is divided into a plurality of dispersion compensation intervals each composed of a main segment and a compensation segment. Chromatic dispersion is managed such that the dispersion compensation intervals have a non-zero net dispersion at every boundary point between them, or such that the number of zero-dispersion boundary points is reduced. The main segment is a series of repeater sections with negative dispersion, while the compensation segment is a single repeater section with positive dispersion.

Abstract: A system operable to modulate a signal according to phase-shift keying (PSK) modulation includes a translator and a phase modulation system. The translator receives data signals and translates the data signals into control signals, where the number of control signals is greater than the number of data signals. The phase modulation system includes phase modulators. Each phase modulator receives a control signal and PSK modulates a communication signal according to the control signal.

Abstract: An optical node includes a plurality of optical input components operable to receive a plurality of signals communicated in an optical mesh network. A plurality of optical drop components coupled to the plurality of optical input components, each optical drop component operable to select a signal to drop to one or more associated client devices from any one of the plurality of optical input components. A plurality of optical output components operable to transmit a plurality of signals to be communicated in the optical mesh network, and a plurality of optical add components coupled to the plurality of optical output components and operable to transmit copies of a plurality of optical add signals to the plurality of optical output components. Each optical output component is operable to select a signal to communicate in the optical mesh network received from any one of the plurality of optical add components and the plurality of optical input components.