| Patent application number | Description | Published |
|---|
| 20080199182 | Transmission system and transmission method - A wavelength division multiplexing system according to the present art adjusts the amount of dispersion compensation (the amount of dispersion compensation of an NZ-DSF and a DCF) every all spans on the basis of the time slot when an intensity modulation signal transmitter outputs an intensity modulation signal and the wavelength interval when a wavelength coupler multiplexes a phase modulation signal (output from a phase modulation signal transmitter) and the intensity modulation signal. | 08-21-2008 |
| 20080266648 | SIGNAL LIGHT MONITORING APPARATUS, OPTICAL AMPLIFICATION APPARATUS AND OPTICAL RECEPTION APPARATUS, AND SIGNAL LIGHT MONITORING METHOD - According to an aspect of an embodiment, an apparatus includes an optical branching unit for branching an input signal light in four directions, a polarization component extraction unit extracting four polarization components having mutually different polarization parameters from lights branched in four directions by the optical branching unit, and a determination unit determining input/non-input of the signal light based on the four polarization components extracted by the polarization component extraction unit. | 10-30-2008 |
| 20090047028 | QUADRATURE PHASE-SHIFT KEYING MODULATOR AND PHASE SHIFT AMOUNT CONTROLLING METHOD FOR THE SAME - The improved quadrature phase shift keying modulator has a structure such that the average light output power of phase-shift keying modulation light output from the combining unit is changed according to the phase difference between the first and the second optical signal after being combined by means of applying driving signals different in eye crossing percentage by the first modulator and the second modulator, respectively, and has a power monitor monitoring the average light output power of quadrature phase-shift keying modulated light and a phase shift controlling unit which performs feedback control of the phase shift amount in the phase shifting unit based on the average light output power monitored by the power monitor. | 02-19-2009 |
| 20090097866 | OPTICAL RECEIVING DEVICE AND OPTICAL TRANSMISSION SYSTEM - According to an aspect of an embodiment, an apparatus includes: a wavelength-to-transmission quality characteristic obtaining unit for obtaining a wavelength-to-transmission quality characteristic; a residual dispersion-to-transmission quality characteristic saving unit for saving a residual dispersion-to-transmission quality characteristic; a wavelength-to-residual dispersion characteristic generating unit for generating a wavelength-to-residual dispersion characteristic from a relationship between the wavelengths of the other channels and the residual dispersion based on the wavelength-to-transmission quality characteristic and the residual dispersion-to-transmission quality characteristic; a variable dispersion compensator for providing variable dispersion compensation to another channel,; and a variable dispersion compensation controlling unit for performing setting control on a dispersion compensation amount. | 04-16-2009 |
| 20090220242 | OPTICAL ADDING AND DROPPING DEVICE AND OPTICAL TRANSMISSION APPARATUS - An optical adding and dropping device includes a drop section including an input port and having a through port and a plurality of drop ports set as output ports, a first multiplexer adapted to multiplex light from the through port and light from a plurality of add ports, and a spectrum foot removing section provided on the input side of the first multiplexer and adapted to remove a foot of a spectrum of light to be inputted from the add ports to the first multiplexer. The optical adding and dropping device can be configured at a low cost while it has adding and dropping functions. | 09-03-2009 |
| 20090238571 | OPTICAL TRANSMISSION SYSTEM AND METHOD FOR CHROMATIC DISPERSION COMPENSATION - An optical transmission system including an optical transmission path for transmitting WDM signals multiplexed different wavelength optical signals, the WDM signals including different bit rate optical signals or different modulation format optical signals; a repeater arranged in the optical transmission path, the repeater including a chromatic dispersion compensation unit for compensating chromatic dispersion compensation for the WDM signals; and a network management system including processes of determining a dispersion compensation ratio indicating the ratio with respect to the dispersion compensation amount at which the residual dispersion of the WDM signals are zero after transmission via the optical transmission path, on the bases of the mixture ratio of different optical signals included in the WDM signals, and variably setting the dispersion compensation amount for the in-line repeater according to the dispersion compensation ratio. | 09-24-2009 |
| 20090274469 | Polarization multiplexed optical transmitting and receiving apparatus - In a polarization multiplexed optical transmitting and receiving apparatus, output light from a light source section of a transmission unit is separated in a polarization separating section, and then modulated in first and second modulation sections, and the modulated lights are synthesized in a polarization synthesizing section, and transmitted to an optical transmission line. Then the polarization multiplexed light propagated through the optical transmission line is demodulated in a reception section of a reception unit, and together with this, transmission characteristic information of the reception light is transferred to the transmission unit. The transmission unit that receives the transmission characteristics information controls a delay section that adjusts a delay amount of relative phases of drive signals of the modulation sections, so that the transmission characteristics of the polarization multiplexed light are within an allowable range. As a result, pulse timing between orthogonal polarization components of the polarization multiplexed light can be flexibly changed with a simple configuration. | 11-05-2009 |
| 20100028003 | WDM optical transmission system and controlling method thereof - In the WDM optical transmission system, when performing a correction of a control target value of the total light intensity per one channel of the WDM light in each node on a transmission path, a correction value calculation section of each node determines the type of its own node, and if it corresponds to a node (for example, OADM node) that demultiplexes the WDM light into individual channels and performs a predetermined processing, performs correction of the control target value of the total light intensity according to a calculation expression with use of a noise cut ratio. The noise cut ratio is defined according to a filtering characteristic for when demultiplexing the WDM light into individual channels, so that the influence due to removal of the noise components distributed across the intermediate region of each channel due to filtering is reflected in the correction processing of the control target value of the total light intensity. | 02-04-2010 |
| 20100284689 | Input signal detection device - According to an aspect of an embodiment, a signal detector device includes a first monitor unit, a second monitor unit, and a discriminator unit. | 11-11-2010 |
| 20100322622 | OSNR MONITOR DEVICE AND OSNR MEASUREMENT DEVICE - An OSNR monitor device includes an optical receiver including a delay interferometer which inputs an optical signal in accordance with a given bandwidth and outputs two optical signals and causes the optical signals to interfere with each other and optical detectors which outputs currents in accordance with optical powers of the optical signals output from the interferometer, an optical power monitor configured to obtain the optical powers of the optical signals received by the optical detectors included in the optical receiver, and an OSNR calculator configured to calculate an optical signal-to-noise ratio in accordance with the optical powers obtained from the optical power monitor and the reception bandwidth. | 12-23-2010 |
