Patent application number | Description | Published |
20080232808 | Optical waveform controlling apparatus - According to an aspect of an embodiment, an apparatus for controlling optical waveform, comprises: an input port for inputting a signal light having a modulating frequency and a signal light power; a pump light generator generating pulsed pump light having a frequency higher than the modulating frequency of the signal light and a pulsed pump light power; a nonlinear optical medium for transmitting the signal light from the input port and the pulsed pump light, the nonlinear optical medium having a gain of the signal light based on a nonlinear optical effect; and a power adjustor for adjusting a gain of the signal light saturates in the nonlinear optical medium by a nonlinear optical effect by adjusting at least one of the signal light power or the pulsed pump light power. | 09-25-2008 |
20080232817 | Waveform shaping apparatus, optical transmission system, and waveform shaping method - A waveform shaping apparatus includes a quantum dot optical amplifier in which an amplification factor of input signal beams saturates if the optical power of the signal beams is equal to or greater than a predetermined value; and a quantum dot saturable absorber in which an absorption factor of the input signal beams saturates if the optical power of the signal beams is under a predetermined value. The quantum dot optical amplifier and the quantum dot saturable absorber are connected in series with a transmission path of the signal beams, and shape the waveform of the signal beams. Voltages applied to the quantum dot optical amplifier and the quantum dot saturable absorber, respectively, are adjusted based on the optical power of the signal beams. | 09-25-2008 |
20090010656 | Optical waveform measurement system and optical waveform measurement method - In an optical waveform measurement system, a phase comparator compares phases between an electric signal output from a PD and an electric signal output from a mixer, and outputs a signal having an amplitude proportional to the phase difference of the two electric signals to a VCO via an LPF, as an error signal. A BPF removes a jitter from the electric signal output from the VCO, and a sampling pulse light source outputs sampling light based on the electric signal with the jitter removed. An optical sampling gate samples signal light to be measured with sampling light output from a sampling pulse light source, and the sampled signal light to be measured is measured by an oscilloscope. | 01-08-2009 |
20090097854 | OPTICAL SIGNAL PROCESSING APPARATUS - An O/E conversion element converts an input NRZ optical signal into an electric signal. A clock recovery circuit recovers a clock signal from the electric signal obtained by the O/E conversion element. A phase modulator applies phase modulation to the NRZ optical signal, using the recovered clock signal. An intensity modulator applies intensity modulation to the NRZ optical signal, using the recovered clock signal. A dispersion medium compensates for a frequency chirp of an optical signal output from the intensity modulator. | 04-16-2009 |
20090190207 | Optical signal processing apparatus, optical receiving apparatus, and optical relay apparatus - An optical signal processing apparatus includes an input unit to which signal light is input; a wave coupling unit that couples the signal light from the input unit and pump light having a waveform different from that of the signal light; a first nonlinear optical medium that transmits light coupled by the wave coupling unit, the light being the signal light and the pump light; a dispersion medium that transmits the light that has been transmitted through the first nonlinear optical medium; and a second nonlinear optical medium that transmits the light that has been transmitted through the dispersion medium. | 07-30-2009 |
20090207489 | OPTICAL PROCESSING DEVICE AND OPTICAL PROCESSING METHOD - An optical processing device includes: a light source that outputs second light having a first polarization state or a second polarization state in synchronization with the pulse timing of the pulse of first light; a first nonlinear medium that controls the polarization state of the first light pulse in accordance with the polarization state of the second light pulse, using a nonlinear effect; and a separator that outputs the first light pulse from the first nonlinear medium selectively to a first output path or a second output path in accordance with the polarization state controlled by the first nonlinear medium. In this device, the first nonlinear medium uses the nonlinear effect to compensate the level of each first light pulse output selectively to the first output path or the second output path by the separator, with each first light pulse receiving the energy of the second light pulse. | 08-20-2009 |
20090240473 | Optical noise index calculation method, optical noise index calculation apparatus, and optical sampling oscilloscope - A method is for calculating an optical noise index of a signal light extraction apparatus that extracts a part of signal light by inputting signal light and a control optical pulse different from the signal light in polarization plane by a given angle to a nonlinear optical medium, and by making light output from the nonlinear optical medium pass through an orthogonal polarizer having a polarization plane orthogonal to that of the signal light. The method includes calculating an output optical noise of the signal light extraction apparatus using a ratio of a power of the signal light that is taken out by the control optical pulse, a parametric gain of the nonlinear optical medium, and a power of a quantum noise of the light having passed through the orthogonal polarizer; and calculating an optical noise index using the output optical noise. | 09-24-2009 |
20090290882 | OPTICAL SIGNAL PROCESSING DEVICE - Signal light, pumping light and control light having different wavelengths are input to a nonlinear optical medium. The power of the pumping light is controlled to generate a desired gain in the nonlinear optical medium. The power of the control light is controlled to saturate the gain of the nonlinear optical medium. | 11-26-2009 |
20100021105 | OPTICAL SIGNAL PROCESSING DEVICE - An optical signal processing device has nonlinear optical medium, first and second power controllers, and polarization controllers. To the nonlinear optical medium, signal light, and first and second pumping lights having wavelengths different from the signal light are input. The first and the second power controllers are provided at the input side of the nonlinear optical medium, and control the powers of the first and the second pumping lights so that a predetermined gain is obtained in the nonlinear optical medium. The polarization controllers are provided at the input side of the nonlinear optical medium, and adjust the first and the second pumping lights so that the polarization states of the first and the second pumping lights are mutually orthogonal. | 01-28-2010 |
20100054753 | APPARATUS AND METHOD FOR STABILIZING POLARIZATION STATE - An apparatus includes: a polarizing beam splitter for splitting the input light into a first light and a second light and for outputting the first light and the second light into optical paths, respectively; a polarization rotator rotating polarized light of the light path by approximately 90 degree; a first path length adjuster adjusting a difference path length between the optical paths in order to be approximately equal to zero; a second path length adjuster adjusting a difference path length between the optical paths in order to be an integer multiple of a wavelength of the input light; an optical attenuator arranged adjusting a propagation loss of the optical path in order to approximately match the propagation losses of the optical paths; and an output element for combining the first light and the second light from the paths and for outputting the output light. | 03-04-2010 |
20100142959 | Optical waveform shaping method and optical waveform shaping apparatus - In an optical waveform shaping apparatus, a WDM signal light is amplified by a first optical amplifier, and thereafter, is input to a first nonlinear medium; a spectrum of the signal light of each wavelength is expanded due to SPM in the first nonlinear medium to thereby separate a signal component and a noise component; and for each spectrum, only a signal component on a short wavelength side is collectively extracted by an optical filter. Then, an output light of the optical filter is amplified by a second optical amplifier, and thereafter, is input to a second nonlinear medium, and the wavelength of each signal light is collectively shifted to a longer wavelength side due to self-frequency shifting in the second nonlinear medium, to thereby return the wavelength of each signal light to that for when each signal light contained in the WDM signal light has been input. As a result, the signal light of each wavelength contained in the WDM signal light can be collectively waveform shaped, and also, the wavelength of each signal light after waveform shaped can be precisely the same as that before waveform shaped. | 06-10-2010 |
20100157417 | Optical-signal processing apparatus - An optical-signal processing apparatus includes a polarizer that is provided at an output terminal of an optical fiber, and polarization control units that adjust a first excitation light and a second excitation light input to the optical fiber. The polarization control units adjust polarization states of the first excitation light and the second excitation light so that, when the first excitation light and the second excitation light are input to the polarizer, polarization directions of the first excitation light and the second excitation light are orthogonal to each other, and angular difference between the polarization direction of the first excitation light and the polarization direction of the second excitation light, measured against the polarization main axis of the polarizer, is equal to or smaller than a threshold value. | 06-24-2010 |
20100166426 | OPTICAL SIGNAL PROCESSING DEVICE - An optical signal processing device includes a waveform width widening unit configured to widen a waveform width of an optical signal; and an optical limiter circuit, to which the optical signal the waveform width of which is widened is input, configured to suppress an intensity of the optical signal in a region where an input intensity and an output intensity are not proportional. | 07-01-2010 |
20100183303 | OPTICAL PULSE GENERATING DEVICE AND OPTICAL SIGNAL PROCESSING DEVICE - An optical pulse generating device includes a continuous light input unit to which continuous light is input; a pulse input unit to which control pulse light that includes periodic pulses of light is input; and a generating unit that generates pulse light from the continuous light by clipping the continuous light according to a variation of emission intensity of the control pulse light. | 07-22-2010 |
20100221014 | OPTICAL FIBER TRANSMISSION SYSTEM AND METHOD - An optical fiber transmission system including: a first transmission-line optical fiber to input first wavelength signal light output from a transmitter, and to change a waveform of the signal light; an optical coupler to combine the first wavelength signal light that has been propagated through the first transmission-line optical fiber with second wavelength pumping light; an optical limiter to input coupled light output from the optical coupler, saturating a gain as power of the coupled light increases using a nonlinear optical medium, thereby suppressing an optical noise component included in the coupled light, and to output signal light including the first wavelength optical component obtained from the nonlinear optical medium; and a second transmission-line optical fiber to input to a receiver after signal light output from the optical limiter is input and a waveform change by the first transmission-line optical fiber in the signal light is compensated for. | 09-02-2010 |
20110044684 | Optical switch and optical waveform monitoring device utilizing optical switch - The polarization direction of an optical signal is changed by a polarization controller so as to be orthogonal to a main axis of a polarizer. A control pulse generator generates control pulses from control beam with a wavelength which is different from the wavelength of the optical signal. The optical signal and the control pulse are input to a nonlinear optical fiber. In the nonlinear optical fiber, the optical signal, during a time period in which the optical signal and the control pulse coincide, is amplified with optical parametric amplification around a polarization direction of the control pulse. The optical signal, during the time period in which the optical signal and the control pulse coincide, passes through the polarizer. | 02-24-2011 |
20110176202 | OPTICAL AMPLIFIER AND OPTICAL AMPLIFYING APPARATUS - An optical amplifier amplifies signal light and includes a pump light source that outputs pump light of a wavelength different from that of the signal light; a combining unit that combines the signal light and the pump light output by the pump light source, to output combined light; an amplifying unit that has non-linear optical media that transmit the combined light to amplify the signal light, the amplifying unit further removing, in the non-linear optical media, idler light generated from the signal light and the pump light, and outputting light that results; and an extraction filter that extracts the signal light from the light output by the amplifying unit. | 07-21-2011 |
20110229138 | Optical-signal processing apparatus, optical transmission method, receiver, and optical network system - In an optical network system: control light is generated by optical modulation based on a modulated data signal which is generated by modulation of a carrier signal with a data signal; and the control light is optically combined with an optical carrier which is to propagate through a nonlinear optical medium, so as to cause cross phase modulation of the optical carrier with the control light in the nonlinear optical medium. | 09-22-2011 |
20110255874 | OPTICAL SIGNAL PROCESSING APPARATUS, OPTICAL RECEIVING APPARATUS, AND OPTICAL RELAY APPARATUS - An optical signal processing apparatus includes an input unit to which signal light is input; a wave coupling unit that couples the signal light from the input unit and pump light having a waveform different from that of the signal light; a first nonlinear optical medium that transmits light coupled by the wave coupling unit, the light being the signal light and the pump light; a dispersion medium that transmits the light that has been transmitted through the first nonlinear optical medium; and a second nonlinear optical medium that transmits the light that has been transmitted through the dispersion medium. | 10-20-2011 |
20120020665 | Optical signal processor - A probe light source produces probe light having a second wavelength different from a first wavelength of signal light. To a light modulator, the probe light and signal light produced from the probe light source are supplied. The light modulator multiplexes the probe light and signal light produced from the probe light source, and supplies it to a nonlinear optical medium. Further, the light modulator modulates the probe light by an intensity change of the signal light in the nonlinear optical medium, and outputs modulated light having the second wavelength based on the data of the signal light. | 01-26-2012 |
20120189308 | OPTICAL SIGNAL-PROCESSING APPARATUS, RECEIVING APPARATUS, AND OPTICAL NETWORK SYSTEM - An optical modulator combines and inputs a signal light propagating through the optical network and a control light having information concerning the optical network to a nonlinear optical medium. The optical modulator modulates the signal light according to changes in intensity of the control light, in the nonlinear optical medium. | 07-26-2012 |
20120301148 | OPTICAL SIGNAL PROCESSING APPARATUS AND OPTICAL COMMUNICATION SYSTEM - In an optical signal processing apparatus, carrier light propagates through a nonlinear optical medium. An optical combiner optically combines output control light for generating idler light of the carrier light with the carrier light. An optical splitter splits the idler light from the carrier light. A receiver acquires a signal multiplexed on the carrier light from the idler light split by the optical splitter. | 11-29-2012 |
20130084072 | OPTICAL RECEPTION APPARATUS AND OPTICAL NETWORK SYSTEM - An optical apparatus includes a dispersing medium configured to receive carrier light which has been subjected to phase modulation in accordance with subcarrier modulation signals which has been modulated using data signals, and a signal extractor configured to extract the data signals from light output from the dispersing medium. | 04-04-2013 |
20130223842 | OPTICAL SIGNAL TRANSMITTING DEVICE, OPTICAL SIGNAL TRANSMITTING METHOD, FREQUENCY FLUCTUATION SUPPRESSING DEVICE AND FREQUENCY FLUCTUATION SUPPRESSING SYSTEM - An optical signal transmitting device includes direct modulators configured to be driven using electric signals of channels to generate directly-modulated optical signals of channels, a beat light source configured to generate beat light at a specific frequency spacing, subcarrier converters configured to modulate, using the beat light from the beat light source, the directly-modulated optical signals of the channels from the direct modulators to generate optical subcarrier modulation signals of channels, probe light sources configured to generate probe light of channels having frequencies that are different from frequencies of the directly-modulated optical signals of the channels, multiplexers configured to multiplex, for individual channels, the optical subcarrier modulation signals of the channels with the probe light of the channels, and nonlinear optical media configured to perform, for individual channels, optical cross modulation for the optical subcarrier modulation signals and the probe light, which are multiplexed, and transmit processed signals. | 08-29-2013 |
20130266320 | OPTICAL TRANSMISSION SYSTEM - An optical transmission system includes: multiplex transmitting devices, each configured to modulate, with an optical carrier, a data signal modulated into light by an optical modulator in a non-linear optical medium arranged on a transmission path so as to multiplex the data signal into the optical carrier, the data signal having a frequency different in each of the multiplex transmitting devices; a receiving device configured to execute optical-to-electrical conversion on the optical carrier received from the transmission path so as to execute reception process of the data signals multiplexed by the multiplex transmitting devices; and a management device configured to specify a frequency band to be used, based on a modulation band of each of the optical modulators, and manage assignment of the frequency of each of the data signals within the frequency band to be used so as to avoid an effect of harmonics generated upon the optical-to-electrical conversion. | 10-10-2013 |
20130272709 | OPTICAL FREQUENCY-DIVISION MULTIPLEXER, OPTICAL COMMUNICATION SYSTEM, AND OPTICAL FREQUENCY-DIVISION MULTIPLEXING METHOD - An optical frequency-division multiplexer includes: a first optical coupler configured to receive a first wavelength-division multiplexed light obtained by wavelength-division multiplexing a first carrier light and a first monitor light and split the first carrier light and the first monitor light from each other; an optical modulator configured to optically modulate the split first carrier light using a signal including a first data signal so as to multiplex the first data signal with the first carrier light; a receiver configured to receive a branched part of the split first monitor light and demodulate a second data signal from the first monitor light; and a second optical coupler configured to couple a remaining part of the split first monitor light and the first carrier light with which the first data signal has been multiplexed. | 10-17-2013 |
20140064732 | APPARATUS AND METHOD FOR RECEIVING OPTICAL SIGNAL, AND OPTICAL FREQUENCY-DIVISION-MULTIPLEXING TRANSMISSION SYSTEM - An optical signal receiving apparatus includes: a chromatic dispersion medium having an amount of chromatic dispersion which is determined according to a frequency of the sub-carrier modulation signals so as to receive the sub-carrier modulation signals, a photodetector configured to convert the carrier optical signal that has passed through the chromatic dispersion medium, into electrical signals, and a signal receiving unit configured to receive an electrical signal selected from the electrical signals obtained by the photodetector. | 03-06-2014 |
20140099114 | OPTICAL SIGNAL TRANSMITTING APPARATUS, OPTICAL FREQUENCY DIVISION MULTIPLEX TRANSMISSION SYSTEM, AND OPTICAL SIGNAL COMMUNICATION METHOD - An optical signal transmitting apparatus is disposed in an optical frequency division multiplex transmission system that includes plural nodes that are in an optical transmission path and respectively use a unique frequency to frequency-multiplex information with a carrier wave to transmit the information to an optical signal receiving apparatus in the optical transmission path. The optical signal transmitting apparatus outputs the carrier wave and includes a transmitting unit into which information to be delivered to the nodes is input, the transmitting unit transmitting the information using a frequency that does not overlap the unique frequencies used by the nodes; and a multiplexing unit that frequency-multiplexes output of the transmitting unit and the carrier wave, and sends the frequency-multiplexed output to the optical transmission path. | 04-10-2014 |
20140099115 | TRANSMITTING APPARATUS, RECEIVING APPARATUS, OPTICAL FREQUENCY DIVISION MULTIPLEX TRANSMISSION SYSTEM, AND OPTICAL SIGNAL COMMUNICATION METHOD - A transmitting apparatus is used in an electrical frequency division multiplex transmission system including nodes that are on an optical transmission path and that respectively frequency-multiplex a sub-carrier of a unique frequency and a carrier wave to transmit information to a receiving apparatus on the optical transmission path. The transmitting apparatus is disposed in each node and includes a determining unit that receives an input of information concerning unused sub-carriers of a transmission signal in the optical transmission path and determines transmission of the information to the receiving apparatus using an unused sub-carrier; an electrical frequency division multiplex transmission unit that using a frequency of the unused sub-carrier determined by the determining unit, modulates the input information to be transmitted to the receiving apparatus; and a coupling unit that adds to the transmission signal in the optical transmission path, a modulated modulation signal. | 04-10-2014 |
20140119725 | OPTICAL TRANSMISSION SYSTEM AND CONTROL METHOD - An optical transmission system includes multiple multiplexers connected in series and each multiplexing an optical signal and given signal light. Each of the multiplexers includes a multiplexing unit that multiplexes the given signal light that is subject to multiplexing and a second optical signal of a frequency that is adjacent to the frequency of a first optical signal that is included in the given signal light; a monitoring unit that monitors deviation between timings of the first optical signal that is included in the signal light multiplexed with the second optical signal by the multiplexing unit, and the second optical signal; and an adjusting unit that based on a result of monitoring by the monitoring unit, adjusts the timing of the second optical signal that is to be multiplexed with the given signal light, by the multiplexing unit. | 05-01-2014 |
20140147119 | OPTICAL SIGNAL PROCESSING APPARATUS AND OPTICAL SIGNAL PROCESSING METHOD - An optical signal processing apparatus includes a mixer and a first optical modulator. The mixer modulates a carrier signal of a first specific frequency received from a first oscillator with an information signal to generate a subcarrier modulated signal. The first optical modulator optically modulates, with the subcarrier modulated signal received from the mixer, carrier light optically modulated by a second optical modulator at a second specific frequency received from a second oscillator to generate and output modulated carrier light. | 05-29-2014 |
20140161452 | OPTICAL FREQUENCY DIVISION MULTIPLEXER AND POLARIZATION CONTROL METHOD - An all-optical modulator includes a directional coupling unit that multiplexes, on a carrier light beam, a signal light beam of a modulation signal that a carrier signal at a characteristic frequency is modulated with an information signal. The all-optical modulator includes a nonlinear medium that cross-phase-modulates the carrier light beam with the multiplexed signal light beam, and frequency-multiplexes the information signal in the signal light beam on the carrier light beam to generate an optical frequency division multiplexed signal. The all-optical modulator includes a monitoring control unit that controls a polarization control unit that controls a polarization state of the signal light beam in a direction in which an intensity of a modulation component takes a maximum value, based on the intensity of the modulation component involved in a modulation signal at a desired characteristic frequency of the optical frequency division multiplexed signal. | 06-12-2014 |
20140233957 | OPTICAL SIGNAL PROCESSING APPARATUS, TRANSMISSION APPARATUS, AND OPTICAL SIGNAL PROCESSING METHOD - An optical signal processing apparatus includes: an optical frequency comb generation unit configured to generate an optical frequency comb; an extraction unit configured to extract a plurality of optical components having a certain frequency interval between the optical components from the optical frequency comb; and an optical carrier generation unit configured to multiplex the plurality of optical components with reference light to thereby generate an optical carrier having a center frequency away from the center frequency of the reference light by an integer multiple of the frequency interval. | 08-21-2014 |
20140269784 | RELAY DEVICE AND OPTICAL NETWORK SYSTEM - A relay device includes: a first port, a plurality of second ports, a splitter configured to branch first optical signals input from the first port into the plurality of second ports; and a plurality of optical modulators configured to modulate shared carrier light by multiplexing the carrier light with a plurality of second optical signals with different frequencies input from the plurality of second ports and by inputting the multiplexed carrier light into a plurality of nonlinear optical mediums, and to transmit the carrier light to the first port. | 09-18-2014 |