| Entries |
| Document | Title | Date |
|---|
| 20080199188 | Interferometric communication - Embodiments of interferometric communication are disclosed. | 08-21-2008 |
| 20080212979 | OPTICAL TRANSMITTER AND OPTICAL TRANSMISSION CONTROL METHOD - An exemplary aspect of the invention is an optical transmitter that emits a light signal, including: a light source; a Mach-Zehnder optical modulator; a modulator driver; a wavelength information holder; and a driving voltage controller, wherein the Mach-Zehnder optical modulator modulates the light intensity of output light from the light source by use of a modulator driving signal, the modulator driver outputs the modulator driving signal according to an input data signal, the wavelength information holder holds wavelength information on the output light of the light source, the driving voltage controller outputs, to the modulator driver, a control signal for setting the latest driving voltage, according to the wavelength information from the wavelength information holder. | 09-04-2008 |
| 20080226305 | INTEGRATED OPTICAL WAVEFORM MODULATOR - A method of modulating an optical carrier. A target carrier modulation is computed based on an input data signal. An effective length of an optical modulator is then controlled based on the target carrier modulation. | 09-18-2008 |
| 20080232820 | Optical Vector Modulator - An optical vector modulator includes an information generator that generates a plurality of N-bit streams at an output where each of the plurality of N-bit streams represents a desired modulation point in a signaling constellation. A memory look-up table having an N-bit address input retrieves a first and a second stored value that corresponds to the N-bit address input, where each of the first and the second stored value represent a respective one of a first and a second modulation vector of a desired modulation point in the signaling constellation. A first and a second digital-to-analog converter generates first and second analog signals, respectively, that correspond to respective ones of the first and second modulation vectors of the desired modulation points in the signaling constellation. A dual-drive interferometric modulator modulates the first and the second analog signals on the optical beam to obtain the desired modulation points in the signaling constellation. | 09-25-2008 |
| 20080240732 | OPTICAL COMMUNICATION MODULE AND CONTROL METHOD THEREOF - An optical communication module includes a driving unit, an optical transmitting unit, a control unit and a signal transform control unit. The driving unit outputs a bias signal and a modulation signal in accordance with a bias control signal and a modulation control signal. The optical transmitting unit is electrically connected to the driving unit, outputs an optical signal in accordance with the bias signal and the modulation signal, and generates a feedback signal. The signal transform control unit is electrically connected to the driving unit and generates the bias control signal and the modulation control signal to be inputted to the driving unit. The control unit is electrically connected to the optical transmitting unit and the signal transform control unit, and controls the signal transform control unit in accordance with the feedback signal. A control method of the optical communication module is also disclosed. | 10-02-2008 |
| 20090003840 | Controlling a bias voltage for a Mach-Zehnder modulator - In one embodiment, the present invention includes a controller coupled to an optical modulator to receive a dither signal, determine a difference between the dither signal and a previous dither signal, determine a derivative of the difference with respect to a bias voltage difference between first and second bias voltages, and control a bias voltage for the optical modulator based on the derivative. Other embodiments are described and claimed. | 01-01-2009 |
| 20090041470 | Multi-wavelength signal generation device and multi -wavelength light generation method - It is an object of the present invention to provide a multiple wavelength signal generation device capable of generating lights of more wavelengths, and a generation method for multiple wavelength light using a multiple wavelength signal generation device. | 02-12-2009 |
| 20090041471 | REMODULATING CHANNEL SELECTORS FOR WDM OPTICAL COMMUNICATION SYSTEMS - The present invention provides a remodulating channel selector for a wavelength division multiplexed optical communication system. The remodulating selector receives a WDM input signal, selects a particular optical channel from the WDM signal and places the information from the selected signal onto a newly-generated optical output signal. The wavelength of the output optical signal can be the same as or different from one of the optical channels which comprises the WDM input signal. When used in a WDM optical communication system with remodulators at the transmission input, the remodulating selectors provide complete control over the interfaces with optical transmitters and receivers, permitting use with a broad range of optical equipment. | 02-12-2009 |
| 20090067852 | Optical modulator and optical transmitter - A reduction in size and cost of an optical modulator is achieved with a simple configuration, while improving the modulation characteristics. An optical modulator modulates light branched by an optical coupler and then couples the light via the optical coupler. The optical coupler is formed in a substrate having electro-optic effects. An optical waveguide is formed in the substrate and, includes a turnback section and ends into which the light branched by the optical coupler is input. A signal electrode is provided in the substrate along the optical waveguide. A modulation signal to modulate the light passing through the optical waveguide is input to the signal electrode. | 03-12-2009 |
| 20090080904 | Optical transmitting apparatus and setting-value determining method - A wavelength-variable light source generates light having a wavelength according to an input wavelength control current. An EA modulator modulates light generated by the wavelength-variable light source, based on a modulation characteristic corresponding to an input EA bias. A TEC changes the temperature of the wavelength-variable light source and that of the EA modulator according to an input temperature control current. A control unit adjusts the setting-value of the wavelength control current input to the wavelength-variable light source, the setting-value of the EA bias input to the EA modulator, and the setting-value of the temperature of the EA modulator according to input wavelength data. | 03-26-2009 |
| 20090087196 | METHOD AND SYSTEM FOR SPLIT VOLTAGE DOMAIN TRANSMITTER CIRCUITS - Methods and systems for split voltage domain transmitter circuits are disclosed and may include amplifying a received signal in a plurality of partial voltage domains. Each of the partial voltage domains may be offset by a DC voltage from the other partial voltage domains. A sum of the plurality of partial domains may be equal to a supply voltage of the integrated circuit. A series of diodes may be driven in differential mode via the amplified signals. An optical signal may be modulated via the diodes, which may be integrated in a Mach-Zehnder or a ring modulator. The amplified signals may be communicated to the diodes, connected in a distributed configuration, via even-mode coupled transmission lines. The partial voltage domains may be generated via stacked source follower or emitter follower circuits. The voltage domain boundary value may be at one half the supply voltage due to symmetric stacked circuits. | 04-02-2009 |
| 20090123162 | CONTROLLER FOR OPTICAL TRANSMISSION DEVICE - A controller supplies a driving signal to an optical modulator for modulating light from a light source in accordance with the driving signal, a low frequency signal being superposed on the driving signal. A bias unit monitors a low frequency component of the modulated light and controls bias of the optical modulator. A compensation unit controls the intensity of the light so as to compensate for refractive index variation of the optical modulator which is caused by variation of the bias. | 05-14-2009 |
| 20090123163 | METHOD OF PRODUCING A HIGHLY PERMEABLE STABLE RF WAVEFRONT SUITABLE AS A DATA CARRIER - A method for generating a highly permeable stable broadband wavefront includes generating a modulated photon wave associated with a modulated data signal, the modulated photon wave comprising plural energized particles, directing the modulated photon wave to an incident surface of a charge transformer and transforming the plural energized particles within the charge transformer. The transformed particles are at substantially zero charge. The method also includes generating a wavefront at an exit surface of the charge transformer including the transformed particles at substantially zero charge. | 05-14-2009 |
| 20090136240 | Balanced Phase-Shaped Binary Transmission In Optical Communications - Optical communication apparatus, methods, systems are provided based on balanced-detection phase-shaped binary transmission (BD-PSBT). | 05-28-2009 |
| 20090214223 | CMOS-COMPATIBLE TUNABLE MICROWAVE PHOTONIC BAND-STOP FILTER - According to one embodiment, a microwave photonic band-stop (MPBS) filter uses an electrical input signal to drive an optical Mach-Zehnder modulator. A modulated optical carrier produced by the modulator is applied to an optical filter having at least two tunable spectral attenuation bands that are located substantially symmetrically on either side of the carrier frequency. The resulting filtered optical signal is applied to an optical-to-electrical (O/E) converter to produce an electrical output signal. | 08-27-2009 |
| 20090220248 | Embedded Parametric Monitoring of Optoelectronic Modules - An optoelectronic module for converting and coupling an information-containing electrical signal with an optical fiber including a housing having an electrical input for coupling with an external electrical cable or information system device and for transmitting and receiving information-containing electrical signals over such input, and a fiber optic connector adapted for coupling with an external optical fiber for transmitting and receiving an optical signal; an electro-optic subassembly coupled to the information containing electrical signal and converting it to and/or from a modulated optical signal corresponding to the electrical signal; and parametric storage means disposed in said housing for storing environmental and/or operational data associated with the module, and an optional method for time-biased lossy compression of such stored data. | 09-03-2009 |
| 20090232517 | DITHERLESS OPTICAL MODULATOR CONTROL - A method of controlling the operating parameters of an optical modulator, without using a dither signal, is provided. Past operating parameters are compared to present operating parameters using a quality of modulation signal obtained by cross-correlating the data modulation signal used to drive the optical modulator with the modulated optical signal output from the optical modulator. The quality of modulation signal is used to optimize the operating parameters (e.g., bias point) of the optical modulator, or other operating parameters of the arrangement, such as the modulator drive level, timing alignment, etc. | 09-17-2009 |
| 20090252500 | Optical Modulator - It is an object of the invention to provide an optical modulator in which a connection substrate or a terminal substrate is disposed outside an optical modulation element and which can maintain at a proper voltage amplitude value a modulation signal applied to an optical modulation element. An optical modulator includes: a substrate having electro-optic effect; an optical waveguide formed on the substrate; an optical modulation element | 10-08-2009 |
| 20090274470 | Optical Code Communication System - An optical code communication system comprises an optical transmitter, an optical receiver, and an optical transmission line. The optical receiver has an optical mixing decoder for mixing a coded light and a local light, dividing the mixed light into an object optical frequency and a non-object optical frequency, and outputting the lights and a detection adder-subtractor filter for detecting the object optical frequency and the non-object optical frequency, filtering the intermediate frequency signals, subtracting one of the intermediate frequency signal from the other, and outputting the resultant intermediate frequency signal. The coded light and the local light are coherent with each other between the optical frequency chips constituting the coded light when detected. The optical mixing decoder or detection adder-subtractor filter regulates the phase of the intermediate frequency signal within the passband when filtered so that the output value or the absolute value of the intermediate frequency signal within the passband when filtered is different when the optical receiver receives a coded light modulated with a different value of the transmission data. | 11-05-2009 |
| 20090310976 | Illuminative light communication system - An light source control unit controls the flashing of a light source and the light amount of a light source according to information to be transmitted. Thus, light, which is modulated according to the information to be transmitted, is emitted from the light source. The light emitted from the light source is made to enter an optical fiber to pass therethrough and enter a light-scattering body which scatters and radiates the modulated light incident from the optical fiber. The scattered light serves as illumination light as it is. Furthermore, if the illumination light is decoded by a decoding unit after being received by a photoreceptor unit of a receiving set, then information carried by the illumination light can be received. | 12-17-2009 |
| 20090324251 | Tunable Radio Frequency and Microwave Photonic Filters - RF and microwave devices and techniques are disclosed for processing RF and microwave signals by using (1) photonic or optical components and (2) RF and microwave components. In some implementations, a part of the processing is performed in the RF and microwave domain such as applying a microwave or RF input signal to control an optical modulator, and another part of the processing is performed in the optical domain such as optical filtering of the modulated optical beam to select desired microwave or RF spectral components. The frequency of a selected spectral component can be tuned by either tuning the frequency of the optical beam that is modulated by the optical modulator or a filter that is used to filter modulated optical beam. | 12-31-2009 |
| 20090324252 | Optical Transmitter - An optical transmitter includes a light source that outputs light superposed with a pilot signal having a predetermined frequency; an optical modulating unit that modulates the light from the light source according to an input electric signal; a detecting unit that detects a high-output-side maximum value of signal light output from the optical modulating unit, a fluctuation width of the high-output-side maximum value, and a fluctuation width of a low-output-side minimum value; a bias-potential adjusting unit that adjusts a bias potential of an electric signal to be input to the optical modulating unit based on the detected maximum value; and an amplitude adjusting unit that adjusts an amplitude of the electric signal to be input to the optical modulating unit based on the fluctuation width of the high-output-side maximum value and the fluctuation width of the low-output-side minimum value. | 12-31-2009 |
| 20100003035 | LASER DIODE HAVING AN ABRUPT TURN-ON, OPTICAL TRANSMITTER DEVICE USING THE SAME LASER DIODE AND OPTICAL COMMUNICATION APPARATUS - Provided are a laser diode which has low power consumption and can realize a high on/off extinction ratio by small variation of current and which can modulate optical signals at high speed, an optical transmitter, and an optical communication apparatus including the optical transmitter. The laser diode having an abrupt turn-on characteristic, comprises: an active region in which light is generated by application of current and gain is controlled; and an absorption region absorbing light generated in the laser diode at a current lower than an abrupt threshold current that is the same as or lower than an operation current, the operation current being a current level that allows the laser diode to generate a target optical power, wherein the output optical power rapidly increases at the abrupt threshold current. | 01-07-2010 |
| 20100003036 | Communication apparatus and signal reception method - A communication apparatus in accordance with an embodiment comprises a reception unit configured to demodulate a received signal to output a first demodulated signal in dependence on a reception condition. The communication apparatus further comprises a pattern detection unit configured to detect a characteristic pattern in the first demodulated signal to output a pattern detection signal, and a pitch detection unit configured to detect a pitch of the characteristic pattern based on the pattern detection signal to output a first signal detection signal indicating that the first demodulated signal is one of an in-phase signal and a quadrature signal, or an inverted version of the one of the in-phase signal and the quadrature signal. | 01-07-2010 |
| 20100021179 | OPTICAL FIELD RECEIVER AND OPTICAL TRANSMISSION SYSTEM - An optical field receiver comprises an optical brancher that branches a received optical multilevel signal into first and second optical signals; an optical delayed detector that performs delayed detection on the first optical signal by a delayed detector with a delay time of T/2 (where T is equal to a symbol time) and a phase difference of 90 degrees; a balanced optical receiver that converts the optical signal outputted from the first delay detector to an electric signal; and an optical intensity receiver that converts the second optical signal to an electric signal; and an electric field calculating part that generates, from the output signals of the first and second optical receivers, first and second reproduced signals indicative of the phase angle and amplitude value of the received symbol represented by the complex signal in each symbol time T. | 01-28-2010 |
| 20100021180 | COMPLEMENTARY OPTICAL WIRING APPARATUS - A complementary optical wiring apparatus includes an optical transmitter, first and second optical transmission lines, and an optical receiver, the optical transmitter has a first operation mode of transmitting an optical signal synchronized with the rising of one electrical input signal via the first optical transmission line and transmitting an optical signal synchronized with the falling thereof via the second optical transmission line, and a second operation mode of transmitting an optical signal synchronized with the rising and falling of one of two electrical input signals via the first optical transmission line and transmitting an optical signal synchronized with the rising and falling of the other electrical input signal via the second optical transmission line, and is operated after one of the two operation modes is selected. | 01-28-2010 |
| 20100021181 | Device, System, and Method of Communication Using Path State Modulation - A communication method including: modulating one more information data bits at a first site by selectively switching the path state of a first stream of photons, and demodulating said information data bits at a second site by detecting appearance and disappearance of an interference pattern of a second stream of photons correlated with said first stream of photons. | 01-28-2010 |
| 20100092183 | FREQUENCY TUNABLE TERAHERTZ CONTINUOUS WAVE GENERATOR - A frequency tunable terahertz continuous wave generator controls the number of feedbacks of an optical signal output from an optical intensity modulator by adding a feedback loop between input and output terminals of the optical intensity modulator, thereby simply tuning a frequency of a terahertz continuous wave. | 04-15-2010 |
| 20100104294 | Optical modulation device - The present invention discloses an optical modulation device, which comprises an electric signal generator generating an electric signal carrying a data signal; a first sinusoidal signal generator generating a first sinusoidal signal; an optical signal generator generating an input source optical signal; and an optoelectronic modulator(Mach-Zehnder modulator) receiving the input source optical signal, the electric signal and the first sinusoidal signal, biased to modify a transmission performance of the input source optical signal, modulating the input source optical signal with the electric signal and the first sinusoidal signal, and then sending out an output source optical signal carrying the electric signal and the first sinusoidal signal. The present invention realizes frequency multiplication, enables an optical signal to carry vector signals, and promotes the efficiency of broadband systems. | 04-29-2010 |
| 20100135673 | APPARATUS AND METHOD FOR TRANSMITTING AND RECEIVING AN INFORMATION SYMBOL IN A VISIBLE LIGHT COMMUNICATION SYSTEM FOR COLOR CODE MODULATION - A visible light communication system and method for transmitting and receiving an information symbol in a visible light communication system for a Color Code Modulation (CCM) scheme using a chromaticity diagram. The method includes determining a first coordinates value corresponding to an information symbol to be transmitted on the chromaticity diagram; determining a first color ratio corresponding to the first coordinates value; determining a second coordinates value corresponding to a compensation symbol for compensating for the first color ratio into a color white and determining a second color ratio corresponding to the second coordinates value; and emitting a visible ray corresponding to each of the first color ratio and second color ratio. The first and second coordinates values are located on a line on the chromaticity diagram. | 06-03-2010 |
| 20100142976 | TRANSMITTING CIRCUIT AND COMPLEMENTARY OPTICAL WIRING SYSTEM - A transmitting circuit has a first transmitter configured to generate a first electric pulse signal in synchronization with a rising edge of a digital electric input signal, a second transmitter configured to generate a second electric pulse signal in synchronization with a falling edge of the digital electric input signal, a first variable impedance circuit configured to supply a bias current to a first light-emitting element only for a predetermined period before the first light-emitting element for converting the first electric pulse signal into a first light signal is supplied with the first electric pulse signal, and a second variable impedance circuit configured to supply a bias current to a second light-emitting element only for a predetermined period before the second light-emitting element for converting the second electric pulse signal into a second light signal is supplied with the second electric pulse signal. | 06-10-2010 |
| 20100172654 | LIGHT EMITTING ELEMENT CIRCUIT, LIGHT TRANSMITTING SYSTEM, LIGHT TRANSMITTING MODULE, AND ELECTRONIC DEVICE - A light emitting element circuit has a light emitting element, a drive circuit that supplies a current to the light emitting element, and a signal circuit that autonomously supplies a signal according to an ambient temperature. The signal adjusts the current such that the current corresponds to a temperature characteristic of the light emitting element. | 07-08-2010 |
| 20100178064 | OPTICAL DEVICE AND OPTICAL TRANSMITTER - An optical device and an optical transmitter are provided. The optical device includes a substrate, a first optical waveguide that may be formed in the substrate and may have a bending portion, and a second optical waveguide that intersects with the bending portion of the first optical waveguide, wherein a groove may be formed outside the bending portion of the first optical waveguide in the substrate. | 07-15-2010 |
| 20100202784 | OPTICAL MODULATOR - In an optical modulator, lights that have been branched by an input optical branching section are input via curved waveguides to a plurality of optical modulation sections arranged in parallel on the same substrate. In the optical modulation sections, optical branching sections of an MZ type optical waveguide are arranged shifted to an output side in the longitudinal direction (x direction) of the substrate, corresponding to an arrangement of input ends of signal electrodes. As a result, even if the input ends of the signal electrodes of the respective optical modulation sections are arranged side by side with a predetermined spacing on one side face of the substrate, input light can be applied to the respective optical modulation sections at low loss, without incurring an increase in the drive voltage. | 08-12-2010 |
| 20100209119 | APPARATUS FOR CONTROLLING LIGHTING EQUIPMENT FOR LIGHTING COMMUNICATION - Disclosed is an apparatus for controlling an illumination device for optical communication, including an optical array having a plurality of light emitting elements, a visible ray communication unit for outputting an electrical signal for visible ray communication, an optical array driving unit for providing a control signal for individually controlling ON/OFF of the plurality of light emitting elements, and a logic operation unit for performing logic operations on signals provided from the visible ray communication unit and the optical array driving unit, and outputting resultant operated signals to the optical array. | 08-19-2010 |
| 20100232806 | OPTICAL TRANSMITTER DEVICE AND OPTICAL TRANSMITTER MODULE - Provided are an optical transmitter device and an optical transmitter module which are capable of reducing the optical transmitter module size while maintaining a state where an excellent optical transmission waveform quality is obtained over a wide range of frequencies. The optical transmission module ( | 09-16-2010 |
| 20100254714 | DATA TRANSMISSION WITH ROOM ILLUMINATIONS HAVING LIGHT EMITTING DIODES - Lamps having light emitting diodes configured for data transmission require the high-frequency circuit of higher power. In order to simplify the required electronics, the light emitting diodes are divided into groups and the groups are modulated differently. Due to the multilevel modulation, the symbol rate can be reduced with the data rate remaining the same, thus reducing the switching rate and the circuitry complexity. | 10-07-2010 |
| 20100260505 | SYSTEM AND METHOD FOR GENERATING MULTILEVEL CODED OPTICAL SIGNALS - A simple and effective all-optical system, producing a multilevel coded optical signal based on the M-ASK technology and by the minimized equipment. The novel all-optical modulation technique for optical M-ASK generation is based on nonlinear interaction between optical signals, say between N 2-ASK modulated pump signals having extinction ratio ER | 10-14-2010 |
| 20110002697 | METHOD AND APPARATUS FOR OPTICAL SIGNAL POWER DISCRIMINATION - The present invention provides an optical power level discriminating device and method for discriminating optical power levels. The optical discriminating device includes a splitter for receiving an optical signal having first and second signal states, and splitting the received optical signal into a first and a second branch optical signal. A first optical fiber for transporting the first branch optical signal is provided that is made of a material having a high non-linear refractive index providing a different non-linear phase shift to the first and second signal states of the first branch optical signal. A second optical fiber is provided for transporting the second branch optical signal with little or no non-linear effect. The discriminating device also includes a combiner for combining the first branch optical signal and second branch optical signal to produce an output optical signal. The output signal is resulted from a constructive interference between the first signal states of the first and second branch optical signals, and a destructive interference between the second signal states of the first and second branch optical signals. | 01-06-2011 |
| 20110033192 | Small Packaged Tunable Optical Transmitter - According to one embodiment, the present application includes a tunable optical transmitter configured in a small package. The tunable optical transmitter includes a housing with a volume formed by exterior walls. An electrical input interface is positioned at the first end of the housing and configured to receive an information-containing electrical signal. An optical output interface is positioned at the second end of the housing and configured to transmit an optical communication beam. A tunable semiconductor laser is positioned in the interior space and operable to emit a laser beam having a selectable wavelength. A semiconductor-based modulator is positioned in the interior space along an optical path of the laser beam and operatively coupled to the optical output interface. The semiconductor-based modulator is configured to impart modulation to the laser beam corresponding to an information-containing electrical signal received through the electrical input interface. | 02-10-2011 |
| 20110033193 | MODULATION METHOD, MODULATION PROGRAM, RECORDING MEDIUM, MODULATION DEVICE, AND OPTICAL TRANSMITTER - A modulation method according to the invention is applied to a modulation device in which a light source is driven by a differential signal while a modulation circuit and the light source are capacitively coupled. In the modulation method of the invention, when an average potential fluctuates at an input terminal of the light source, a potential fluctuation is externally provided using a control circuit such that a normal phase side and a reverse phase side become equal to each other in a time constant of the fluctuation in average potential, and transient states of the average potentials at the normal phase side and reverse phase side are equalized and cancel each other as in-phase components of a signal input to the light source, which allows an optical signal to be normally transmitted from the light source. The optical signal can normally be transmitted from the light source even before the average potentials at a normal phase input terminal and a reverse phase input terminal of the light source are stabilized. | 02-10-2011 |
| 20110044700 | OPTICAL COMMUNICATIONS SYSTEM - The present invention relates to an optical communications system that allows improving OSNR while suppressing the power increase of pumping light for distributed Raman amplification. In the optical communications system, an optical fiber is laid in a transmission section between a transmitter station (or repeater station) and a receiver station (or repeater station), and optical signals are transmitted from the transmitter station to the receiver station via the optical fiber. In the optical communications system, pumping light for Raman amplification, outputted by a pumping light source provided in the receiver station, is fed into the optical fiber via an optical coupler, and the optical signals are distributed-Raman-amplified in the optical fiber. The transmission loss and the effective area of the optical fiber satisfy, at the wavelength of 1550 nm, a predetermined relationship. | 02-24-2011 |
| 20110044701 | LIGHT MODULE, ILLUMINATION SYSTEM AND METHOD INCORPORATING DATA IN LIGHT EMITTED - Proposed is a light module ( | 02-24-2011 |
| 20110097091 | TIME DELAY ADJUSTMENT DEVICE AND METHOD - A time delay adjustment method is provided, which includes the following steps. A same scrambling signal is added into two received signals. The added scrambling signals are then extracted. A delay difference between the two signals is detected according to a difference between the two extracted scrambling signals. The delay difference between the two signals is adjusted by delaying one or both of the two signals. Furthermore, a time delay adjustment device and an optical transmission apparatus are also provided. Therefore, time delay can be adjusted online, and real-time monitoring and adjustment of delay difference is also achieved. | 04-28-2011 |
| 20110116808 | REFLECTIVE OPTICAL TRANSMITTER - A semiconductor optical amplifier (SOA) is used in a double pass configuration with one of the output ports followed by an attenuator, which is followed by a modulator with a reflective facet. The variable loss between the SOA and the modulator is optimised, so that the SOA can be operated in a highly saturated regime without distorting the modulated signal. The SOA is firstly saturated by the input carrier, ( | 05-19-2011 |
| 20110129232 | EXTERNAL MODULATOR MONITORING DEVICE AND EXTERNAL MODULATOR MONITORING METHOD - This invention relates to external modulator monitoring device and method for monitoring an external modulator. The external modulator monitoring device includes a mixing unit for mixing optical signals modulated by the external modulator and optical signals not modulated by the external modulator, so as to obtain multiple branches of mixed optical signals; an electrical differential unit for converting the multiple branches of mixed optical signals into corresponding multiple branches of electrical signals, and performing a differential processing on voltages of the multiple branches of electrical signals to obtain differential signals; and a power detection unit for detecting power of the differential signals. | 06-02-2011 |
| 20110229148 | OPTICAL MODULATION APPARATUS AND OPTICAL MODULATION METHOD - An optical modulation apparatus includes a first modulator, a second modulator, a multiplexer, a detector and an adjustor. The first modulator modulates light emitted by a light source using a first input signal and outputs a first modulated signal. The second modulator modulates the light using a second input signal and outputs a second modulated signal. The multiplexer multiplexes the first and second modulated signals and outputs a multiplexed signal. The detector is configured to detect a dip where power in a waveform of the multiplexed signal is equal to or smaller than a predetermined value. The adjustor is configured to adjust a delay of the first and second input signals based on power at the dip. | 09-22-2011 |
| 20110236033 | Optical Field Transmitter and Optical Transmission System - It is provided an optical field transmitter comprising a light source, one or more DA converters, an optical field modulator, a complex information multilevel signal generator circuit, and a phase pre-integration circuit. The optical field modulator modulates light output from the light source into a optical field signal by using the analog signal converted from a complex multilevel information signal including phase pre-integration complex information by the one or more DA converters. A phase angle of the complex multilevel information signal at a complex signal point is any one of values of integral multiples obtained by dividing 360 degrees by a positive integer N. An amplitude value of the complex multilevel information signal at the complex signal point is any one of values of a positive integer M. A total number of the complex signal points which may be taken is lower than a product of N and M. | 09-29-2011 |
| 20110255875 | DUAL RATE QPSK/TCM-QPSK OPTICAL MODULATION - The present disclosure allows for optical link capacity to be optimized based on transmission parameters, such as amplifier gain, link loss, optical signal-to-noise ratio. For example, optical signals at wavelengths that are susceptible to impairments, such as non-linear effects, or that are not adequately amplified by an optical amplifier, may be modulated in accordance with lower rate/less spectrally efficient modulation formats (“low rate formats”) that are more noise tolerant. On the other hand, those optical signals at wavelengths that are less susceptible to or do not incur such impairments may be modulated in accordance with highly spectrally efficient /higher rate modulation formats (“high rate formats”) that are more noise sensitive. Accordingly, a maximum or optimized capacity may be realized through appropriately choosing, for each channel, a particular modulation format and channel spacing. Such optimized capacity can be readily obtained with adaptive driver circuits. | 10-20-2011 |
| 20110299858 | HOST DEVICE WITH MULTIPURPOSE OPTICS DRIVE CAPABILITIES - A host device is provided that can leverage multiple optical modulation scheme capabilities of the optical module. The host device comprises an electrical modulator unit configured to generate electrical transmit signals comprising modulated data in a modulation format, and a connector configured to connect to the optical module that transmits optical signals to an optical fiber. The host device comprises a controller that is configured to select one of a plurality of optical modulation schemes for an optical reach, and to generate a control signal for supply to the optical module via the connector. The control signal is configured to cause the optical module to generate optical signals from the electrical transmit signals according to the selected optical modulation scheme. | 12-08-2011 |
| 20120002978 | OPTICAL SINGLE-SIDEBAND TRANSMITTER - A method for generating an optical single sideband signal comprising the steps of splitting an optical field into two parts and introducing a relative phase delay of +/−π/4 radians in each direction of transmission to one of the parts, intensity reflection-modulating each part with electrical signals having a relative phase delay of +/−π/2 radians and then recombining the reflection-modulated signals. | 01-05-2012 |
| 20120008963 | OPTICAL MODULATOR, OPTICAL TRANSMISSION DEVICE, AND BIAS ADJUSTING METHOD - Included are a first modulator, a second modulator, a first optical amplifier that amplifies an output of the first modulator at an amplification factor based on a first bias signal, a second optical amplifier that amplifies an output of the second modulator at an amplification factor based on a second bias signal, an optical phase adjuster that phase-rotates an output of the second optical amplifier, an optical multiplexer that multiplexes an output of the first optical amplifier with an output of the optical phase adjuster, and a second bias corrector that generates a first pulse signal and a second pulse signal, which are complementary to each other, and obtains a first bias value and a second bias value based on a change of strength of an output signal of the optical multiplexer. The first and second pulse signals are superimposed on the first and second bias signals, respectively. | 01-12-2012 |
| 20120082466 | UPSAMPLING OPTICAL TRANSMITTER - Consistent with the present disclosure, data, in digital form, is received by a transmit nodes of an optical communication, and converted to analog signal by a digital-to-analog converter (DAC) to drive a modulator. The modulator, in turn, modulates light at one of a plurality of wavelengths in accordance with the received data. The modulated light is then transmitted over an optical communication path to a receive node. At the receive node, the modulated optical signal, as well as other modulated optical signals are supplied to a photodetector circuit, which receives additional light at one of the optical signal wavelengths from a local oscillator laser. An analog-to-digital converter (ADC) is provided in the receive node to convert the electrical signals output from the photodetector into digital form. The output from the ADC is then filtered in the electrical domain, such that optical demultiplexing of individual channels is unnecessary. | 04-05-2012 |
| 20120082467 | OPTICAL TRANSMITTER, OPTICAL TRANSMISSION DEVICE, AND METHOD OF CONTROLLING OPTICAL TRANSMITTER - An optical transmitter includes a driver outputting data; an optical modulator outputting an optical modulation signal by modulating light from a light source based on the data output from the driver; a detector detecting at least one of a signal intensity of the optical modulation signal from the optical modulator and a signal intensity of the data from the driver and outputs a detection result; and an adjustor adjusting a signal parameter of the data based on the detection result. | 04-05-2012 |
| 20120087677 | METHOD AND APPARATUS FOR TRANSMITTING DATA USING VISIBLE LIGHT COMMUNICATION - A transmitting apparatus using visible light communication generates a light source control signal from color information representing additional information and transmits additional information with a color of light that is emitted by a light source by controlling an on/off time of a plurality of LEDs according to the light source control signal. Therefore, a user can intuitively know additional information from a color of light that is emitted by the light source. | 04-12-2012 |
| 20120106979 | OPTICAL TRANSMITTER AND OPTICAL TRANSMISSION APPARATUS - An optical transmitter is disclosed. An optical modulator outputs an optical signal by modulating light being input, and has an optical absorption characteristic which changes a degree of optical absorption depending on a bias voltage being applied and includes a first characteristic region and a second characteristic region in which the degree of the optical absorption is greater than the first characteristic region. An power source applies an electric field generated by applying a predetermined shutdown bias voltage corresponding to the second characteristic region to electrodes provided in two interference optical guides formed in the optical modulator, when an output of the optical signal from the optical modulator is shut down to be less than or equal to a desired amount. | 05-03-2012 |
| 20120183306 | OPTICAL TRANSMITTER INCLUDING EA MODULATOR AND DRIVER - An optical transmitter to drive the EA modulator integrated with an LD in a mode of lowered power consumption. The optical transmitter includes the optical device integrating the LD with the EA modulator, and the driver to modulate the EA modulator in the differential mode by being supplied with the modulation signal between the anode and the cathode common to the LD. | 07-19-2012 |
| 20120189321 | Dual Drive Externally Modulated Laser - A method of generating a signal in an optical transmitter comprising a directly modulated laser and an amplitude modulator for modulating the output of the laser. The method comprises the steps of applying a first modulation signal representing data to be transmitted to the current of the laser such that the output frequency of the laser is modulated, and applying a second modulation signal representing the data to be transmitted to the amplitude modulator such that the amplitude of the laser output is modulated. | 07-26-2012 |
| 20120224865 | PHASE LOCKED LOOP - An optical phase-locked loop (OPLL) comprising a phase-frequency detector; first and second lasers; a local oscillator; a detector and a low pass filter; operably connected in a circuit comprising a feedback path. The OPLL can also include a pre-scaler, a second local oscillator and a mixer. | 09-06-2012 |
| 20120269522 | DIFFERENTIAL TRANSMISSION CIRCUIT AND INFORMATION PROCESSING SYSTEM - A differential transmission circuit includes a grounded conductive layer, a pair of transmission line conductors, a conductive film and a via hole which connects the grounded conductive layer to the conductive film. The differential transmission circuit further includes a straight-line region which is present in the differential transmission circuit through which a differential transmission signal output by a driving circuit is transmitted and in which the pair of transmission line conductors extends parallel so as to have a first width, and a band rejection filter region in which the pair of transmission line conductors planarly overlaps the conductive film and extends parallel so as to have a second width narrower than the first width and a common mode of the differential transmission signal is attenuated at one of the frequencies which are natural number multiples of a frequency corresponding to the predetermined bit rate. | 10-25-2012 |
| 20120294627 | OPTICAL MODULATION METHOD AND SYSTEM - The present invention provides an optical modulation method and system. The method includes: loading a first dither signal on an amplitude of an input data signal; loading a second dither signal on a bias voltage; and according to the bias voltage loaded with the second dither signal, obtaining a modulation signal according to the data signal whose amplitude is loaded with the first dither signal, and outputting the modulation signal as an output optical signal, where the first dither signal and the second dither signal are signals of the same frequency and the same phase, and a ratio of amplitudes of the signals is determined according to a tracking error, so that a feedback signal obtained according to the modulation signal is locked to a required bias point. In the embodiments of the present invention, lock precision may be improved. | 11-22-2012 |
| 20130084078 | Technique for Increasing Signal Gain - A technique for generating complementary signals for joint transmission involves generating a first signal having a first wavelength and a second signal having a second wavelength. The first signal is modulated with a first modulation to encode data, and the second signal is modulated with a second modulation, which is an inverted version of the first modulation, to encode the same data such that the first and second signals are complementary. The first and second signals are combined to produce a combined signal in which power attributable to the first signal is interleaved with and substantially non-overlapping temporally with power attributable to the second signal. The combined signal is amplified and then transmitted. The first and second signals can be optical signals at respective first and second optical wavelengths, where the first and second signals are on-off keying (OOK) modulated. | 04-04-2013 |
| 20130129361 | OPTICAL TRANSMITTER MODULE AND TRANSMITTING METHOD - An optical transmitter module includes at least one light source, at least one optical modulator aligned to the at least one light source one by one, a first light interleaver, and at least one optical fiber. Each light source emits a light wave with a particular wavelength. Each optical modulator modulates the light wave of the corresponding light source, to form a central light wave having the particular wavelength and a number of secondary light waves having secondary wavelengths. The first light interleaver separates the secondary light waves from the central light wave. The at least one optical fiber transmits the secondary light waves. | 05-23-2013 |
| 20130170841 | METHOD AND APPARATUS FOR TRANSMITTING HIGH-LEVEL QAM OPTICAL SIGNALS WITH BINARY DRIVE SIGNALS - Methods and apparatus for power-efficiently and reliably transmitting high-level quadrature amplitude modulation (QAM) optical signals using binary drive signals. Even though binary signals are used to drive a QAM modulator directly, without digital-to-analog conversion, the methods and apparatus disclosed allow the transmission of pilot symbol sequences having near optimal properties, such as a constant power profile in the time domain; a mean power that is approximately the same as the mean power of the data symbols; and roughly uniform amplitude in the frequency domain for non-zero frequency components of the pilot symbol sequence. The binary drive signals can be processed so that the modulated optical signals are selectively constrained to a subset of points of the QAM constellation to form a QAM constellation with reduced size and a mean power that is approximately the same as the mean power of the original QAM constellation. | 07-04-2013 |
| 20130279919 | VISIBLE-LIGHT COMMUNICATION SYSTEM AND METHOD - Disclosed is a visible light communication system including a transmission device, including multiple light emitting units emitting light of different colors and mapping transmission data to a chromaticity point, calculating luminescence of each of the light emitting units, generating a preamble signal for channel matrix estimation, and emitting light based on the preamble signal and calculated luminescence amount. A reception device of the visible light communication system includes multiple light receiving units and estimates a channel matrix based on a corresponding optical signal when an optical signal corresponding to the preamble signal is received in each light receiving unit, compensates the optical signal corresponding to the chromaticity point for a propagation path based on the estimated channel matrix, detects a chromaticity point on the chromaticity coordinates based on a signal after the propagation path compensation, and demodulates the transmission data. | 10-24-2013 |
| 20130343767 | OPTICAL TRANSMITTER - An optical transmitter includes an equalizer which receives a data signal, an optical modulator driver which amplifies an output signal of the equalizer, and an optical modulator which converts an output signal of the optical modulator driver into an optical signal and outputs the optical signal. The equalizer has a signal line for transmitting the data signal, a coupled line electromagnetically coupled to the signal line, a resistive section connected to the coupled line, and a ground via connected to the resistive section. The equalizer reduces power of the data signal in a frequency range where the frequency response characteristic of the optical modulator driver exhibits peaking, to reduce waveform jitter in the output signal of the optical modulator driver that is input to the optical modulator. | 12-26-2013 |
| 20130343768 | INTER-VEHICLE COMMUNICATION APPARATUS AND METHOD USING VISIBLE LIGHT COMMUNICATION - The present invention relates to an inter-vehicle communication apparatus and method using visible light communication. The inter-vehicle communication apparatus using visible light communication includes a spreading code application unit for applying a spreading code to transmission data desired to be transmitted, and a transmission unit for generating a transmission frame based on the transmission data to which the spreading code is applied, and transmitting the transmission frame via a lighting lamp of a vehicle. The transmission frame includes a preamble field required to synchronize the transmission frame, a data field required to transmit the transmission data, and a position field required to provide hopping information of the transmission data. | 12-26-2013 |
| 20140133867 | PRE-EQUALIZED OPTICAL TRANSMITTER AND PRE-EQUALIZED OPTICAL TRANSMISSION METHOD - A pre-equalization optical transmitter includes: a tap coefficient selecting unit for saving, in advance, a tap coefficients for generating an RZ pre-equalization signal and an NRZ pre-equalization signal, and for selecting and outputting one of the tap coefficients according to the value of a parameter that is a factor of transmission power fluctuations; a pre-equalization signal generating unit for generating the RZ pre-equalization signal or the NRZ pre-equalization signal based on the tap coefficient; and a modulating unit for generating a pre-equalization optical transmission signal by modulating an optical signal input from a light source by using a signal obtained through D/A conversion and amplification of the RZ pre-equalization signal or the NRZ pre-equalization signal, wherein a transmission method is switched between an RZ method and NRZ method by switching the tap coefficients by the tap coefficient selecting unit. | 05-15-2014 |
| 20140140707 | OPTICAL TRANSMISSION DEVICE, METHOD OF OPTICAL TRANSMISSION, AND NON-TRANSITORY COMPUTER-READABLE MEDIUM - An optical transmission device includes: a drive signal generate unit that generates a drive signal; a modulation unit that modulates an optical signal in accordance with the drive signal; a detect unit that detects a fluctuation of a signal component of the drive signal with respect to an optical signal output by the modulation unit; and a correct unit that corrects a parameter of the drive signal generate unit in accordance with a detect result of the detect unit so that a non-linear characteristic of the modulation unit gets closer to a linear characteristic. | 05-22-2014 |
| 20140169802 | MODULATOR FOR OPTICAL TRANSMITTER - An optical transmitter has a modulator for modulating data onto an optical signal for transmission to the receiver, the modulated signal having components at one or more constellations of points of different amplitudes and phases. The modulator is tunable such that distortions of the points of the one or more constellation can be tuned, and a tuning controller is provided for receiving a feedback signal from the receiver indicating a distortion measured at the receiver, and for tuning automatically the modulator to adjust the modulation based on the received feedback signal to pre-compensate for the measured distortion. Such pre-compensation can reduce the amount of distortion in the transmission system and thus enable more transmission capacity, without the need for a complex transmitter. | 06-19-2014 |
| 20140212150 | METHOD AND SYSTEM FOR SPLIT VOLTAGE DOMAIN TRANSMITTER CIRCUITS - Methods and systems for a photonically enabled complementary metal-oxide semiconductor (CMOS) chip are disclosed and may comprise in an integrated circuit comprising a driver: amplifying a received signal in a plurality of partial voltage domains, and generating the partial voltage domains in a domain splitter in the driver. A voltage domain boundary value between two partial voltage domains may be controlled utilizing a differential amplifier that samples an output voltage of a cascade amplifier that is an input to the driver and controls a current supplying said cascade amplifier. A series of diodes may be driven in differential mode via the amplified signals. An optical signal may be modulated via the diodes, which may be integrated in a Mach-Zehnder modulator or a ring modulator. The diodes may be connected in a distributed configuration. The amplified signals may be communicated to the diodes via transmission lines, which may be even-mode coupled. | 07-31-2014 |
| 20140233962 | OPTICAL MODULATOR MODULE AND MODULATION METHOD FOR OPTICAL SIGNAL - An optical modulator module includes an optical modulator including an optical waveguide which conducts an inputted optical signal, and m modulator regions on the optical waveguide; and m discrete driving circuits serially connected to one another. The discrete driving circuits include a driving circuit which outputs a signal obtained from a digital input signal with a synchronization signal to one of the modulator regions, and a phase shifting circuit which outputs a signal resulting from giving a delay to a signal branched from the synchronization signal. A discrete driving circuit receives the signal outputted from the phase shifting circuit. Each of the modulator regions includes modulation electrodes, an electric field caused by a modulation electric signal applied to each of the modulation electrodes penetrates by a penetration length d, and every two adjacent modulation electrodes has a distance L | 08-21-2014 |
| 20140233963 | OPTICAL OUTPUT DEVICE AND METHOD FOR CONTOROLLING AN OPTICAL TRANSMITTER - Since it is difficult to emit a control a IQ modulator emitting modulated lightwave according to QAM format without signal degradation of said emitted signal due to low frequency dither used for the control of said modulator, a method for controlling an optical transmitter according to an exemplary aspect of the invention includes: generating a multilevel electrical signal by means of combining two or more binary electrical signals, where said multilevel signal is used to drive the modulator of adding a low frequency dither signal on several of the binary electrical signals, wherein the phase of the added dither signal depends on the value of the binary signal to which it is added; tapping a portion of light after the modulator and generating a monitor signal from the tapped light; controlling the modulator according to the monitor signal. | 08-21-2014 |
| 20140348514 | METHOD OF CONVERTING AN OPTICAL COMMUNICATIONS SIGNAL AND AN OPTICAL RECEIVER - A method of converting an optical communications signal having a differentially encoded multilevel modulation format into communications traffic bits, the multilevel modulation format having a plurality of constellation points, the method comprising: receiving a consecutive pair of symbol signals of said optical communications signal, the pair of symbol signals being arranged to differentially encode a plurality of communications traffic bits; and generating a plurality of optical binary signals in dependence on the symbol signals, each optical binary signal having a respective binary signal level, wherein the optical binary signals form optical versions of the encoded communications traffic bits. | 11-27-2014 |
| 20140356001 | CHIP-BASED ADVANCED MODULATION FORMAT TRANSMITTER - In various embodiments, a monolithic integrated transmitter, comprising an on-chip laser source and a modulator structure capable of generating advanced modulation format signals based on amplitude and phase modulation are described. | 12-04-2014 |
| 20140363175 | OPTICAL TRANSMITTER AND METHOD OF CONTROLLING OPTICAL TRANSMITTER - An optical transmitter includes a light source configured to generate direct current light; a multi-value modulator configured to modulate the direct current light; an opto-isolator configured to block output light of the multi-value modulator; a driving circuit configured to output a driving signal for driving the multi-value modulator; a bias control circuit configured to control a bias voltage applied to the multi-value modulator, according to an optical output power of the multi-value modulator; and a control circuit configured to control operations of the opto-isolator, the driving circuit and the bias control circuit, wherein the control circuit decreases an amplitude of the driving signal output from the driving circuit while synchronizing with the blocking of the output light of the multi-value modulator by the opto-isolator. | 12-11-2014 |
| 20140369698 | UPSAMPLING OPTICAL TRANSMITTER - An apparatus including a photodiode, a low pass filter, an analog-to-digital converter, an interpolation circuit and a digital signal processor is disclosed. The photodiode receives a portion of a plurality of optical signals, each of which is modulated in accordance with a corresponding one of a plurality of data streams, and each having a corresponding one of a plurality of wavelengths. The photodiode supplies an electrical output. The low-pass filter supplies a filtered output in response to the electrical output. The analog-to-digital converter is configured to sample the filtered output at a first sampling rate to generate a plurality of first data samples. The interpolation circuit is configured to receive the plurality of first data samples and supply a plurality of second data samples at a second sampling rate less the first sampling rate. The digital signal processor circuit is configured to receive the plurality of second data samples. | 12-18-2014 |
| 20150016827 | HIGH-SPEED LOW-JITTER COMMUNICATION SYSTEM - Communication apparatus and techniques, such as for optical communication, can include providing a reference frequency derived from an atomic energy level transition or a molecular energy level transition, generating at least two specified optical carrier signals at least in part using the reference frequency, coherently modulating the specified optical carrier signals using respective baseband information signals to provide respective coherently-modulated optical subcarriers. A combined optical information signal comprising the optical subcarriers can be transmitted to a receiver, such as via a fiber optic cable. In an example, a received optical information signal can be optically Fourier transformed to provide respective coherent outputs, which can be coherently downconverted. | 01-15-2015 |
| 20150023673 | INFORMATION TRANSMISSION SYSTEM, INFORMATION SENDING DEVICE, INFORMATION RECEIVING DEVICE, INFORMATION TRANSMISSION METHOD, INFORMATION SENDING METHOD, INFORMATION RECEIVING METHOD AND PROGRAM PRODUCT - An information transmission system includes: an information sending device including a light emitting section that emits light in a plurality of colors, a modulating section that modulates information to be transmitted into signals composed of changes in color, and a light emission control section that controls the light emitting section to emit light while changing color temporally based on the signals generated by the modulating section; and a receiving device including a camera that captures an image having color, and a control and communication section that detects a temporal color change of the light emitting section emitting light by light emission control by the information transmitting device, from images consecutively captured by the camera, decodes the detected color change into information, and outputs the generated information to a display section. | 01-22-2015 |
| 20150030339 | Optical Transceiver with Isolated Modulator Contacts and/or Inputs - A multi-channel optical transmitter generally includes a first light source configured to emit light of a first wavelength, a second light source configured to emit light of a second wavelength, a first modulator configured to modulate the light of the first wavelength, and a second modulator configured to modulate the light of the second wavelength. The first modulator has a first anode and a first cathode, and the second modulator has a second anode and a second cathode electrically isolated from the first anode and the first cathode. The modulators (and optionally the light sources) are on a common substrate. A method of transmitting optical signals generally includes modulating light emitted from a first light source using a first modulator, and modulating light emitted from a second light source using a second modulator, where the first modulator receives a first modulation signal, and the second modulator receives a second modulation signal electrically isolated from the first modulation signal. | 01-29-2015 |
| 20150050030 | OPTICAL TRANSMITTER AND METHOD FOR CONTROLLING THE SAME - Since it is difficult to control correctly and optimally the DC biases of an IQ modulator driven with pre-equalized data, a method for controlling an optical transmitter according to an exemplary aspect of the invention includes the steps of (a) making direct current biases for driving children Mach-Zehnder modulators of an IQ modulator in the optical transmitter converge to values close to null driving points of the children Mach-Zehnder modulators, (b) driving the children Mach-Zehnder modulators with special driving data including a pair of training patterns between which there is a significant correlation, (c) scanning direct current biases for setting quadrature angle of the IQ modulator, (d) monitoring output of the IQ modulator during step (c), and (e) setting the direct current bias for setting quadrature angle on the basis of the driving data and monitored results in step (d). | 02-19-2015 |
| 20150063826 | OPTICAL WAVEGUIDE WITH CASCADED MODULATOR CIRCUITS - An optical waveguide for transmitting an optical signal input to the optical waveguide with a first frequency. The optical waveguide includes a plurality of modulator circuits configured along an optical transmission channel. Each modulator circuit includes at least one resonant structure that resonates at the first frequency when the modulator circuit that includes the at least one resonant structure is at a resonant temperature. Each modulator circuit has a different resonant temperature. | 03-05-2015 |
| 20150104191 | AMPLIFICATION-FREE ELECTRO-OPTICAL OSCILLATOR - An electro-optical oscillator includes, in part, a modulator, a signal splitter, N photodiodes with N being an integer greater than one, a signal combiner, and a filter. The modulator modulates an optical signal in accordance with a feedback signal. The splitter splits the modulated optical signal into N optical signals each delivered to a different one of N photo-diodes. Each of the N photo-diodes converts the optical signal it receives to a current signal. The signal combiner combines the N current signals received from the N photo-diodes to generate a combined current signal. The filter filters the combined current signal and generates the feedback signal. The electro-optical oscillator optionally includes, in part, N variable optical gain/attenuation components each amplifying/attenuating a different one of the N optical signals generated by the splitter. | 04-16-2015 |
| 20150117868 | PARALLEL OPTICAL TRANSMITTER - An N-channel parallel optical transmitter includes a dual-facet continuous-wave laser, two or more optical splitters, and four or more optical modulators. One of the optical splitters has an input coupled to the first facet of the laser, and another has an input coupled to the second facet of the laser. The outputs of the splitters are coupled to the inputs of the optical modulators. | 04-30-2015 |
| 20150125159 | REFLECTIVE COLORLESS OPTICAL TRANSMITTER - Provided is a reflective colorless optical transmitter receiving a carrier signal, which is a continuous wave, and outputting a modulated optical signal. The reflective colorless optical transmitter includes a semiconductor optical amplifier (SOA) amplifying an input optical signal allowing the input optical signal to have a gain, an optical modulator connected to the SOA and outputting a modulated optical signal, a high reflectivity facet reflecting the modulated optical signal from the optical modulator, and a Bragg reflection mirror connected to the high reflectivity facet, the optical modulator, and the SOA in series, wherein a Bragg resonator is formed by the Bragg reflecting mirror and the high reflectivity facet. | 05-07-2015 |
| 20150139665 | LOW BIT RATE SIGNALING WITH OPTICAL IQ MODULATORS - In one embodiment, a method includes receiving an optical input signal to be modulated by an IQ modulator. The method includes applying data to first and second modulators during a first operation, and applying a first pattern of data to the first modulator and a second pattern of data to the second modulator during a second operation. The second operation results in an optical output signal of the IQ modulator having a low power output and a high power output. The first and second patterns are defined to provide respective desired average powers for a predefined time period based on the low and high power outputs. In another embodiment, a method includes indentifying a transmitter in an optical system by low bit rate signaling. Low bit rate signaling includes receiving an optical input signal from an optical source and transmitting identification data of the transmitter. | 05-21-2015 |
| 20150318926 | COMMUNICATIONS DEVICE AND METHOD - A communications device is disclosed and includes: a first acquiring unit for acquiring first specific wavelength light and second specific wavelength light from a first optical path; a first receiving unit for converting the first specific wavelength light coming from the first acquiring unit into a first electrical signal; a first control unit for sending a first modulating signal to a first loopback unit according to the first electrical signal coming from the first receiving unit; and the first loopback unit for modulating the second specific wavelength light coming from the first acquiring unit according to the first modulating signal, and looping the modulated second specific wavelength light back to a second optical path, where a transmission direction of an optical signal in the second optical path is opposite to a transmission direction of an optical signal in the first optical path. The present invention further discloses a communications method. | 11-05-2015 |
| 20150333477 | METHOD, SYSTEM AND APPARATUS FOR HYBRID OPTICAL AND ELECTRICAL PUMPING OF SEMICONDUCTOR LASERS AND LEDS FOR IMPROVED RELIABILITY AT HIGH TEMPERATURES - A method, system and an apparatus for hybrid optical and electrical pumping of semiconductor lasers and light-emitting diodes (LEDs) improves reliability at high operating temperatures. The semiconductor laser or LED is biased via optical pumping and a relatively small electrical modulation current modulates the laser. At low modulation speeds, the modulation current is substantially lower than that required for biasing the laser or directly modulating it at high speeds. The lifetime of the laser is improved by substantially reducing the operating current, enabling laser lifetimes adequate for operation in many applications, such as deep-hole oil drilling and jet engine control, where operation is not currently possible. | 11-19-2015 |
| 20150341120 | OPTICAL MODULATOR CALIBRATION - A method of optical modulator calibration is disclosed. The method may include modulating, by an optical modulator, a received optical signal with a first electrical signal to generate a modulated optical signal, a polarity of data carried by the modulated optical signal, and an optical power of the modulated optical signal based on a temperature of the optical modulator. The method may also include monitoring the optical power of the modulated optical signal and in response to the optical power of the modulated optical signal being below or equal to a power threshold, adjusting the temperature of the optical modulator. In response to the optical power of the modulated optical signal being above the optical power threshold, the method may also include checking the polarity of the data carried by the modulated optical signal. | 11-26-2015 |
| 20150349894 | METHOD AND DEVICE FOR OPTICAL DATA TRANSMISSION - A method and device for optical data transmission are disclosed. Data bits are transmitted in the form of data symbols, by modulating an optical signal in dependence on the data bits and in accordance with two or more constellation schemes. The data bits are transmitted, by generating first data symbols, which represent respective sets of data bits containing an even number of data bits. The first data symbols are generated, by modulating the optical signal in accordance with a first constellation scheme. Furthermore, the data bits are transmitted, by generating second data symbols, which represent respective sets of data bits having an odd number of data bits. The second data symbols are generated, by modulating the optical signal in accordance with a second constellation scheme. The first and the second data symbols are generated at a predefined symbol rate, such that the first and the second data symbols are interleaved in time. | 12-03-2015 |
| 20160050020 | METHOD AND SYSTEM FOR SPLIT VOLTAGE DOMAIN TRANSMITTER CIRCUITS - Methods and systems for a photonically enabled complementary metal-oxide semiconductor (CMOS) chip are disclosed and may comprise in an integrated circuit comprising a driver: amplifying a received signal in a plurality of partial voltage domains, and generating the partial voltage domains by controlling a voltage domain boundary value between two partial voltage domains utilizing a differential amplifier that samples an output voltage of a cascade amplifier that is an input to the driver and controls a current supplying said cascade amplifier. A series of diodes may be driven in differential mode via the amplified signals. An optical signal may be modulated via the diodes, which may be integrated in a Mach-Zehnder modulator or a ring modulator. The diodes may be connected in a distributed configuration. The amplified signals may be communicated to the diodes via transmission lines, which may be even-mode coupled. | 02-18-2016 |
| 20160056896 | OPTICAL COMMUNICATION DEVICE AND METHOD OF CONTROLLING OPTICAL MODULATOR - An optical communication device includes an optical modulator of a Mach-Zehnder type, a low frequency superimposing circuit configured to superimpose a low frequency signal on a substrate bias voltage applied to the optical modulator, a monitor configured to monitor a modulated light output from the optical modulator, and a substrate bias controller configured to control the substrate bias voltage based upon a low frequency component contained in a monitor signal output from the monitor. | 02-25-2016 |
| 20160056897 | OPTICAL COMMUNICATION DEVICE AND METHOD OF CONTROLLING OPTICAL MODULATOR - An optical communication device has a Mach-Zehnder optical modulator; a monitor configured to monitor a modulated light output from the optical modulator; a first controller configured to set a substrate bias voltage or an amplitude of a drive signal applied to the first waveguide of a waveguide pair of the optical modulator to a desired level that provides a first modulation index; and a second controller configured to control a substrate bias voltage or an amplitude of the drive signal applied to the second waveguide of the waveguide pair based upon an output signal from the monitor such that a second modulation index for the second waveguide becomes the same or closer to the first modulation index set for the first waveguide. | 02-25-2016 |
| 20160065310 | OPTICAL COMMUNICATION APPARATUS AND METHOD OF CONTROLLING OPTICAL MODULATOR - An optical communication apparatus includes an optical modulator having a Mach-Zehnder interferometer with a pair of waveguides and configured to modulate a phase of light emitted from a light source, a first controller configured to control a first substrate bias voltage or an amplitude of a first drive signal applied to a first waveguide of the waveguide pair of the optical modulator based upon an output of the optical modulator or a wavelength of the light source; and a second controller configured to control a second substrate bias voltage or an amplitude of a second drive signal applied to a second waveguide of the waveguide pair of the optical modulator independently from the first controller, based upon the output of the optical modulator or the wavelength of the light source. | 03-03-2016 |
| 20160112137 | OPTICAL TRANSMITTER WITH LINEAR ARRANGMENT AND STACKED LASER PACKAGE AND RF PATH - Described herein is an optical transmitter that includes an RF signal path that is, at least partially, parallel with an optical signal path. In one embodiment, an electrical transmission element, which defines the RF signal path, is disposed between a laser emitting the optical signal and a side wall of a package containing the optical transmitter. Although the RF and optical signals may propagate along different planes within the optical transmitter, both signals are received at an optical modulator. Using the RF signal, the optical modulator modulates the optical signal (e.g., a continuous wave) to generate a modulated optical signal. The optical modulator then outputs the modulated signal to a receptacle coupled to a light carrying medium such as a fiber optic cable. | 04-21-2016 |
| 20160119062 | DRIVER CIRCUIT FOR AN ELECTRO-ABSORPTION OR MICRO-RING MODULATOR AND OPTICAL TRANSMITTER COMPRISING SUCH DRIVER CIRCUIT - A modulator driver circuit for providing a drive voltage to an electro-absorption modulator, such a Franz-Keldysh modulator, or to a micro-ring modulator, and an optical transmitter comprising such driver circuit, where said driver circuit comprises a differential amplifier and at least one differential branch of the differential amplifier being provided with a voltage offset. This provide for a bias voltage being adjustable within the driver circuit itself. Preferably, said differential amplifier is arranged for supplying drive voltage to two complementary driver outputs providing a reverse bias relative to the modulator. In one embodiment, said differential amplifier comprises a cascode in the differential branch not being provided with the voltage offset. | 04-28-2016 |
| 20160127045 | BURST OPTICAL SIGNAL TRANSMISSION DEVICE AND CONTROL METHOD FOR BURST OPTICAL SIGNAL TRANSMISSION DEVICE - A bias point of an external modulator is set to different values according to on and off of a burst control signal and an optical source is driven continuously in a burst optical signal transmission device. The burst optical signal transmission device avoid generation of transient fluctuation of a wavelength and a light amount at the time of burst signal rising. | 05-05-2016 |
| 20160142147 | SMALL PACKAGED TUNABLE LASER TRANSMITTER - A tunable laser transmitter configured in a small package subassembly coupled to a printed circuit board. The tunable laser transmitter includes a housing with a volume formed by exterior walls. An electrical input interface is positioned at the first end of the housing. A first and a second optical output interface is positioned at the second end of the housing, the first output being configured to transmit a modulated optical beam, and the second output configured to transmit a cw beam to the local oscillator of an external receiver. | 05-19-2016 |
| 20160164626 | PARAMETER CONTROL FOR OPTICAL MULTICARRIER SIGNAL - An optical multi carrier signal has a modulation format and has many individual carrier signals. Parameters of the signal are controlled by receiving an indication of individual carrier transmission performance of the individual carrier signals, and selecting parameter values for the individual carrier signals, the parameter values comprising both a carrier FEC overhead and a carrier bandwidth for the modulation format. Selection is made according to the indicated individual carrier transmission performance and according to an overall spectral efficiency of the multi carrier signal. The selected parameter values are output for control of the optical multi carrier signal. By selecting values for both parameters rather than either one, better optimisation can be obtained since they are interdependent. The control can have better granularity than changing modulation format, and can make better use of bandwidth or improve the overall capacity. | 06-09-2016 |
| 20160191167 | Electro-Optic Modulator With Distributed Gain - An electro-optic modulator includes a Mach-Zehnder interferometer having a bias input, an optical input, and an optical output. A first arm comprises an optical waveguide. A second arm comprises an optical waveguide. A plurality of electrode segments is distributed along or proximate to a length of the optical waveguides of the first and second arms. A plurality of amplifiers, where at least one of the plurality of amplifiers has an RF input that receives an electrical modulation signal, and where each of the plurality of amplifiers are electrically connected to one of the plurality of electrode segments so as to provide distributed gain. A number of the plurality of amplifiers is chosen to achieve a desired combination of noise figure and spur-free dynamic range. | 06-30-2016 |
| 20160191170 | INTEGRATED OPTICAL PHASED ARRAY - An integrated optical phased array includes an input channel receiving an optical input signal, and a multitude of signal processing channels each adapted to supply an associated optical output signal along a first axis in response to the input signal. Each signal processing channel includes, in part, a phase modulator adapted to modulate the phase of the signal travelling through the channel, thereby to control or steer the output signal of the phased array. Each channel optionally includes first and second photo detection circuits respectively generating first and second detection signals. The first and second detection signals in each channel may be used to modulate the amplitude and/or phase of the output signal of that channel thereby to control and steer the output signal of the phased array. | 06-30-2016 |
| 20160191171 | METHODS, CIRCUITS AND OPTICAL CABLE ASSEMBLIES FOR OPTICAL TRANSMISSION OF HIGH-SPEED DATA AND LOW-SPEED DATA - Methods, circuits and active optical cable assemblies for simultaneous transmission of low-speed optical data and high-speed optical data over an optical fiber link are disclosed. In one embodiment, a method of optical communication includes controlling a laser such that an output of the laser transmits high-speed optical data at a first bit rate, and modulating an amplitude of the output of the laser such that the laser transmits low-speed optical data at a second bit rate simultaneously with the high-speed optical data. In another embodiment, a circuit for providing optical communication includes a laser and a laser driver circuit that digitally modulates an output of the laser to transmit high-speed optical data at a first bit rate. The circuit further includes an amplitude modulation circuit that modulates an amplitude of the laser to transmit low-speed optical data at a second bit rate simultaneously with the high-speed optical data. | 06-30-2016 |
| 20160197678 | TWO-SECTION SEMICONDUCTOR LASER WITH MODULATION-INDEPENDENT GRATING SECTION TO REDUCE CHIRP | 07-07-2016 |
| 20160204870 | METHOD OF FABRICATING AND OPERATING AN OPTICAL MODULATOR | 07-14-2016 |
| 20160204871 | METHOD AND SYSTEM FOR DISCRETE MULTI-TONE TRANSMISSION WITH MULTIPLE MODULATIONS | 07-14-2016 |
| 20190149239 | NONLINEAR TOLERANT SUPER-GAUSSIAN DISTRIBUTION FOR PROBABILISTIC SHAPING MODULATION | 05-16-2019 |
| 20190149241 | OPTICAL MODULATOR-BASED TRANSMISSION CONTROL | 05-16-2019 |
