Abstract: A system operable to modulate a signal according to phase-shift keying (PSK) modulation includes one or more phase modulators that comprise one or more fractional phase modulators. A fractional phase modulator includes a splitter that splits a communication signal to yield a first communication signal with first amplitude and a second communication signal with second amplitude, where the ratio of the first and second amplitudes correspond to a phase shift. A phase shifter phase shifts the first or second communication signal. A first modulator modulates the first communication signal at a constant phase. A second modulator modulates the second communication signal at phases corresponding to the phase shift to encode data. A coupler couples the first communication signal and the second communication signal.

Abstract: A system and method for dispersion compensation of an optical signal in a hybrid network includes generating optical traffic in a first set of one or more channels, wherein the traffic in the first set of channels is modulated using a first modulation technique. Optical traffic is generated in a second set of one or more channels, wherein the traffic in the second set of channels is modulated using a second modulation technique. An optical dispersion pre-compensation is applied to the second set of channels. The first set of channels and the second set of channels are combined to form an optical signal, and the optical signal is transmitted over an optical network.

Abstract: A transmitter modulator that is operable to modulate signals according to multiple modulation formats includes a first modulator, a second modulator, and a polarization beam combiner. The first modulator encodes a first signal according to a first modulation format. The second modulator encodes a second signal according to a second modulation format, the first signal orthogonally polarized with respect to the second signal. The polarization beam combiner combines the first signal and the second signal for transmission.

Abstract: A system operable to monitor a polarization controller includes the polarization controller and a polarization controller monitor. The polarization controller polarizes the signal to yield a polarized signal comprising a first signal component and a second signal component, where the first signal component is orthogonally polarized with respect to the second signal component. The polarization controller monitor monitors a first polarization indicating waveform of the first signal component and a second polarization indicating waveform of the second signal component. The polarization controller monitor determines whether to adjust polarization of the received signal by polarization controller in accordance with the first polarization indicating waveform and the second polarization indicating waveform.

Abstract: The present invention has an object to provide a technology for monitoring the quality of a WDM signal light, capable of quickly and accurately judging an occurrence of quality deterioration of signal light and a deterioration factor thereof. To this end, according to a quality monitoring apparatus of WDM signal light of the present invention, a part of the WDM signal light being propagated through an optical transmission path is branched as a monitor light, a signal light of one wavelength contained in the monitor light is selected as a channel to be measured.

Abstract: A polyisocyanate production method that can allow effective use of hydrogen chloride produced secondarily in a polyisocyanate production process, while allowing reduction of environmental burdens, and a polyisocyanate production system for performing the polyisocyanate production method. After chlorine is allowed to react with carbon monoxide to produce carbonyl chloride in a carbonyl chloride producing reactor, the carbonyl chloride produced in the carbonyl chloride producing reactor is allowed to react with polyamine in an isocyanate producing reactor to produce polyisocyanate. Then, after hydrochloric gas produced secondarily in the isocyanate producing reactor is purified in a hydrogen chloride purifying column, the purified hydrochloric gas is oxidized in a hydrogen chloride oxidizing reactor to produce chlorine.

Abstract: In accordance with the teachings of the present invention, a method for protecting traffic in a passive optical network (PON), includes transmitting downstream traffic destined for one or more optical network units (ONUs) from a first set of one or more transmitters. The method further includes substantially simultaneously transmitting the same downstream traffic destined for the one or more ONUs from a second set of one or more transmitters. The method further includes selecting either the downstream traffic from the first set of transmitters or the second set of transmitters for communication to a remote node (RN) of the PON.

Abstract: A polyisocyanate production system is provided that can stably produce chlorine from hydrogen chloride produced secondarily while reacting stably between carbonyl chloride and polyamine and can perform an effective treatment of the hydrochloric gas produced secondarily. A hydrochloric gas control unit 32 controls a flow-rate control valve 23 to keep constant an amount of hydrogen chloride supplied from a hydrogen chloride purifying tank 4 to a hydrogen chloride oxidation reactor 6 via a second hydrochloric-gas connection line 11 to be constant, and also controls a pressure control valve 22 based on an inner pressure of the hydrogen chloride purifying tank 4 input from a pressure sensor 25 to discharge the hydrochloric gas from the hydrogen chloride purifying tank 4 to the hydrogen chloride absorbing column 5 via a first hydrochloric-gas connection line 10, so as to keep an inner pressure of the hydrogen chloride purifying tank 4 to be constant.

Abstract: A plurality of pump light sources generate plural variations of pump light having different frequencies. A modulation circuit intensity-modulates the plural variations of pump light in the predetermined periods, respectively. A pump light pair whose frequency difference equals a Raman shift frequency are modulated such that they cannot simultaneously enters an emission state. A wavelength-multiplexer wavelength-multiplexes the plural variations of pump light modulated by the modulation circuit. A optical guide device guides the plural variations of pump light wavelength-multiplexed by the wavelength-multiplexer to an optical fiber.

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 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: A demodulator includes a 1×m optical coupler and one or more optical device sets. The 1×m optical coupler splits an input signal comprising symbols to yield m signals comprising m/2 pairs of signals. An optical device set is associated with a pair of signals and includes one or more first optical operators, one or more second optical operators, and a set coupler. The first optical operators direct a first signal of a pair of signals along a first path, and the second optical operators direct a second signal of the pair along a second path. The second path introduces a symbol delay between the first signal and the second signal. The set coupler receives the first and the second 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: An optical disc apparatus capable of restraining thermal deformation of an optical disc due to transmission of a heat from a spindle motor to the disc, comprises a turn table rotated by the spindle motor, for holding the disc, a bearing portion provided in the spindle motor, for holding a rotary shaft of the table, and a cooling element provided at the outer periphery of the bearing portion, for thermoelectrically cooling the bearing portion. The bearing portion can be directly cooled by the cooling element. Since the heat from the spindle motor is transmitted to the table through the bearing portion, the heat generated from the motor can be prevented from being transmitted to the table by cooling the bearing portion, and further, the table can be cooled. Thus, no heat is transmitted from the table to the optical disc, thereby thermal deformation of the optical disc can be retrained.

Abstract: In accordance with the teachings of the present invention, a method for distributing traffic in a distribution node in an optical network includes receiving wavelength division multiplexed (WDM) traffic in a plurality of wavelengths at at least one of a plurality of filters at the distribution node from at least one of the one or more upstream terminals. The optical network includes one or more upstream terminals, the distribution node, and a plurality of downstream terminals. Each of the filters is coupled to one or more of the upstream terminals by a plurality of separate fibers. The method further includes separating traffic in a first set of one or more wavelengths from traffic in a second set of one or more wavelengths at the filter. The method further includes routing the traffic in the first set of wavelengths for distribution to all downstream terminals.

Abstract: There is provided an optical disk apparatus that can inhibit, during recording or reproduction of data on or from an optical disk, a side runout that may occur in the optical disk in its circumferential direction as a result of Coriolis force when a disk rotating shift is subjected to procession movement, thereby allowing recording and reproducing quality to be stabilized and a reduced size of the apparatus. The disk apparatus provided has pressure pawls arranged at intervals smaller than those in the prior art, each of which is provided with a plurality of pressing points arranged at intervals larger than those in the prior art. Particularly, an interval between the pressure pawls is an acute angle in terms of the center angle of the disk. An interval between the pressing points is an angle of 35° or larger.

Abstract: In accordance with the teachings of the present invention, a system and method for managing network components in a passive optical network (PON) is provided. In a particular embodiment, the method includes transmitting, at a first wavelength, a first configuration message on the PON, wherein the first configuration message comprises a first transmitter interface number. The method also includes transmitting, at a second wavelength and at approximately the same time as the first message, a second configuration message on the PON, wherein the second configuration message comprises a second transmitter interface number. The method further includes receiving a configuration response message from each of one or more optical network units (ONUs) in a first set of ONUs that comprises the first transmitter interface number and receiving a configuration response message from each of one or more ONUs in a second set of ONUs that comprises the second transmitter interface number.

Abstract: A method is provided for increasing downstream bandwidth in an optical network that includes providing a downstream terminal comprising a digital output path and an analog output path. The method also includes receiving a signal comprising at least one wavelength at the downstream terminal. The method further includes selectively processing the signal at the downstream terminal. The signal is selectively processed at the downstream terminal by processing the signal on the analog output path if the signal comprises analog video data and processing the signal on the digital output path if the signal comprises data to be converted to a digital bit stream.

Abstract: It is an object of the present invention to provide a Raman amplifier capable of easily reducing the wavelength deviation of a Raman gain while suppressing system performance degradation, and an optical transmission system using such a Raman amplifier.

Abstract: A transfer rack 15 loaded with a seriate number of component supply cassettes 14 to be handled collectively is carried and retained on a truck 61 so that it can be taken in and out of the truck 61. The transfer rack 15 is passed between the truck 61 and a component supply section 8. Thus, the withdrawal of the transfer rack 15 from the component supply section 8 to the truck 61 and the delivery of the transfer rack 15 to the component supply section 8 are executed in a timely manner so as to change the component supply cassettes 14 at the component supply section 8. The transfer rack 15 delivered to the component supply section 8 is positioned by operating an automatic positioning means at the component supply section 8 in a direction in which it is loaded and unloaded and in a direction perpendicular to the direction in which it is loaded and unloaded.