Patent application number | Description | Published |
20090238574 | APPARATUS AND METHOD FOR MONITORING OPTICAL GATE DEVICE, AND OPTICAL SWITCH SYSTEM - An optical gate device transmits or interrupts input light according to control information. The optical gate device includes a light-receiver that obtains input and output optical powers of the optical gate device, and a monitor that obtains optical input and output characteristics of the optical gate device based on the control information and the monitored input and output optical powers, the optical input and output characteristics being equivalent to a time the optical gate device is controlled in a transmitted state. | 09-24-2009 |
20090252492 | OPTICAL COMMUNICATION SYSTEM , AND OPTICAL COMMUNICATION METHOD AND COMMUNICATION UNIT THEREFOR - A communication unit inhibits delay and jitter during network communication, improving the communication quality. For this purpose, the communication unit includes: a first terminator that terminates a communication channel in the first optical communication scheme established between the communication unit and another communication unit; a second terminator that terminates a signal in the second optical communication scheme; and a path setting switch that switches between a first signal path setting and a second signal path setting. | 10-08-2009 |
20090322233 | LIght detecting apparatus and output light intensity controller - A light detecting apparatus receives input light branched and output by a branching device, to calculate transmittance and reflectivity from the input light, acquires a wavelength corresponding to the calculated transmittance and reflectivity to calculate a gain value corresponding to input light intensity, acquires a driving current value corresponding to a calculated gain value and an acquired wavelength, and outputs an acquired driving current value. | 12-31-2009 |
20100266293 | RELAY APPARATUS, SIGNAL PROCESSING APPARATUS AND OPTICAL COMMUNICATION SYSTEM - A relay apparatus including: a first interface | 10-21-2010 |
20100321768 | OPTICAL AMPLIFIER, CONTROL CIRCUIT, AND METHOD OF CONTROLLING OPTICAL AMPLIFIER - An optical amplifier includes a semiconductor optical amplifier which has a gain that changes in accordance with a wavelength of input light and which generates a noise light power having different levels in accordance with a drive current, a detector that detects an optical power branched from output light of the semiconductor optical amplifier, and a controller that controls supply of the drive current based on the optical power such that an output light power of the semiconductor amplifier is a sum of a target signal light power and the noise light power. | 12-23-2010 |
20110116161 | OPTICAL AMPLIFIER, CONTROL CIRCUIT, AND OPTICAL AMPLIFIER CONTROL METHOD - An optical amplifier includes a semiconductor optical amplifier, a power monitor configured to monitor an optical power of out-of-signal-band noise output from the semiconductor optical amplifier, and a corrector configured to correct a relationship between a driving current for the semiconductor optical amplifier and a noise optical power based on the out-of-signal-band noise optical power monitored by the first power monitor. | 05-19-2011 |
20110116803 | TERMINAL APPARATUS, DATA TRANSMISSION SYSTEM AND DATA TRANSMISSION METHOD - There is provided a terminal apparatus including a message monitor to gather transmission request information from each of first and second terminating apparatus, a dynamic bandwidth allocation unit to allocate each transmission band in accordance with the gathered transmission request information, determine a size and an alignment position of a time slot in accordance with the allocated transmission band, determine a transmission start time of the time slot, and allocate an extinction period so as to stop a transmission of an optical signal between a time slot of the optical signal with the second transmission rate and a time slot following the time slot of the optical signal with the second transmission rate, and a MAC controller to generate a control frame for notifying each of the first and second terminating apparatus of the transmission start time and the size of the time slot. | 05-19-2011 |
20110286085 | OPTICAL AMPLIFIER - An optical amplifier includes an input port, an output port, an amplification medium, a light source, a monitor, and a controller. The amplification medium with which doped an rare-earth element for optical amplification is allocated on an optical path between the input port and the output port. The light source supplies the amplification medium with an excitation light. The monitor monitors a total power of an optical signal of each wavelength according to a monitor period which is longer than a transient response time of the amplification medium. The controller controls the light source so that a power of the excitation light is constant when a monitor value of the monitor is equal to or smaller than a predetermined threshold value and controls the light source so that an optical gain in the amplification medium is constant when the monitor value is larger than the predetermined threshold value. | 11-24-2011 |
20120257272 | OPTICAL AMPLIFICATION APPARATUS - An optical amplification apparatus includes a front-stage semiconductor optical amplifier which amplifies an input light and a rear-stage semiconductor optical amplifier which amplifies an amplified light outputted from the front-stage semiconductor optical amplifier. The front-stage semiconductor optical amplifier exercises auto level control of an output light by exercising variable control of driving current which flows according to applied voltage higher than light emitting threshold voltage of an internal optical amplification element. The rear-stage semiconductor optical amplifier performs gate switching of a transmitted light by exercising switching control of driving current. By doing so, distortion of a waveform is controlled and optical communication quality can be improved. | 10-11-2012 |
20130028599 | REPEATER, RELAY METHOD AND OPTICAL TRANSMISSION SYSTEM - There is provided a repeater to relay an optical signal transmitted/received between an optical line terminal (OLT) and at least one optical network unit (ONU), the repeater including: a first port configured to receive an optical signal input from the at least one ONU; a converter circuit configured to convert an optical signal of a first transmission rate into an optical signal of a second transmission rate higher than the first transmission rate, the optical signal of the first transmission rate to be converted being included in optical signals received at the first port; and a second port configured to output the optical signal converted by the converter circuit to the OLT. | 01-31-2013 |
20130251365 | OPTICAL POWER MONITOR, OPTICAL POWER CONTROL SYSTEM AND OPTICAL POWER MONITOR METHOD - An optical power monitor that detects optical power of respective wavelengths of a signal light in a wavelength multiplexing system, includes: a light emitter configured to superimpose a frequency modulation component on a signal light; a wavelength tunable filter configured to sweep a pass band of the signal light across a wavelength band for a signal light; and a detector configured to detect intensity changes in optical power passing through the wavelength tunable filter with a frequency modulation of the optical power, and to detect an optical power measurement value at a middle point of two points of the intensity changes of the optical power as the optical power of a wavelength to be measured. | 09-26-2013 |
20140105596 | OPTICAL TRANSMISSION SYSTEM, METHOD OF TESTING OPTICAL TRANSMISSION SYSTEM, AND NON-TRANSITORY COMPUTER-READABLE MEDIUM - An optical transmission system includes: an optical transmission device that has a plurality of optical transmitters configured to output at least one different wavelength and a multiplexer configured to multiplex wavelength lights output by the plurality of optical transmitters and output a multiplexed wavelength light; and a detection unit configured to detect each wavelength light that is branched before being fed into the multiplexer by sweeping an objective wavelength for detection, wherein, in a single sweeping, the detection unit selects and detects two or more wavelength lights with a wavelength interval that is wider than a wavelength interval of an output light of the multiplexer. | 04-17-2014 |
20140205281 | APPARATUS AND METHOD FOR MONITORING WAVELENGTH TUNABLE OPTICAL FILTER - A monitoring apparatus, that monitors a wavelength tunable optical filter for filtering an optical signal to which a frequency modulation component is added, includes: an optical filter configured to filter the optical signal output from the wavelength tunable optical filter; a detector configured to detect amplitude of the frequency modulation component included in the optical signal output from the optical filter; a generator configured to generate an output-side amplitude distribution representing a distribution of the amplitude of the frequency modulation component detected by the detector, by sweeping a transmission wavelength of the optical filter; and a monitoring unit configured to monitor arrangement of a transmission wavelength band of the wavelength tunable optical filter with respect to a spectrum of the optical signal based on the output-side amplitude distribution generated by the generator. | 07-24-2014 |
20140241719 | WAVELENGTH PATH SWITCHING METHOD, OPTICAL COMMUNICATION SYSTEM, OPTICAL COMMUNICATION DEVICE, OPTICAL RELAY DEVICE, AND NETWORK MANAGEMENT DEVICE - At least one of a first device, a second device, and a relay device compensates for wavelength dispersion in a first optical wavelength path. The first or second device changes a wavelength dispersion compensation amount at the first or second device so that wavelength dispersion in a second optical wavelength path is compensated. The relay device changes a wavelength dispersion compensation amount at the relay device so that a total amount of wavelength dispersion of the signal light compensated in the first optical wavelength path does not change substantially with the change in the wavelength dispersion compensation amount at the first or second device. The first optical wavelength path is switched to the second optical wavelength path after the wavelength dispersion compensation amount at the first or second device is changed to a value that can compensate for the wavelength dispersion in the second optical wavelength path. | 08-28-2014 |
20140270781 | OPTICAL SIGNAL DEMODULATOR, OPTICAL SIGNAL DEMODULATING METHOD, AND OPTICAL ADD-DROP MULTIPLEXER - An optical signal demodulator includes: an obtaining unit configured to obtain a spectrum of an optical signal generated by a second signal being superimposed on a first signal using frequency modulation; an identifying unit configured to identify a peak wavelength which is a wavelength corresponding to a peak position of the spectrum; and a demodulating unit configured to demodulate the second signal from the optical signal using a wavelength-variable filter to which a transmitted wavelength band has been set based on the peak wavelength. | 09-18-2014 |