Abstract: Disclosed herein are methods and systems for appliances, including networked or “Internet-of-Things” appliances.

Abstract: Disclosed herein are methods and systems for appliances, including networked or “Internet-of-Things” appliances.

Abstract: In a terminator, a midpoint electrode is provided between a first signal electrode and a second signal electrode, a first resistor is connected between the first signal electrode and the midpoint electrode, a second resistor is connected between the second signal electrode and the midpoint electrode, a first GND electrode is provided on a side opposite to the side where the first resistor is provided with the first signal electrode interposed therebetween, a second GND electrode is provided on the side opposite to the side where the second resistor is provided with the second signal electrode interposed therebetween, and capacitances in the terminator are formed between the first signal electrode and the midpoint electrode, between the second signal electrode and the midpoint electrode, between the first signal electrode and the first GND electrode, and between the second signal electrode and the second GND electrode.

Abstract: Described herein is a solution to address the intrinsic nonlinearity of analog signals and the restrictions this places on the signals dynamic range. The subject matter described herein produces linear electro-optic modulation over a dramatically wider range of the input signal amplitude. This is accomplished by a distributed multiwavelength design that “folds” the large dynamic range across multiple linear subranges, with each subrange being addressed using an optical wavelength. As a result, the subrange within the wide dynamic range of the input signal is captured by the linear portion of the transfer function of a single transfer function. Several physical implementations of this subject are presented herein. This innovation enables the efficient use of optical links for the transmission and processing of analog and multilevel signals, overcoming the limitations that were once hindering progress in this field.

Abstract: A coherent transmitter includes a first beam splitter that splits an input first optical signal to obtain a second optical signal and a third optical signal, a first modulator that modulates the second optical signal to obtain a first modulated signal, a phase shift adjustment unit that adjusts a phase of a first sub-signal in the first modulated signal and adjusts a phase of a fourth sub-signal in the phase-adjusted first sub-signal, a first beam combiner that combines a second sub-signal in the first modulated signal and the phase-adjusted fourth sub-signal to obtain a first combined signal, a first PD that performs optical-to-electrical conversion on the first combined signal to obtain a first electrical signal, and a controller that controls, based on the first electrical signal, a voltage applied to the phase shift adjustment unit.

Abstract: A combinatorial optimization problem processing device is for associating a combinatorial optimization problem having N elements with an Ising model to process the combinatorial optimization problem. The combinatorial optimization problem processing device includes: a 1×2 Mach-Zehnder optical modulator that receives a polarized clock pulse train; an optical interference circuit that receives polarized clock pulse trains that were modulated by the Mach-Zehnder optical modulator; an optical coupler that couples output of the optical interference circuit with an initialization optical pulse train that creates a neutral state with respect to interactions between the elements; and a modulation signal generator that performs waveform shaping on an electrical signal obtained by photoelectrically converting an output signal of the optical coupler, generates a modulation signal for the Mach-Zehnder optical modulator, and externally outputs a monitor signal that represents a solution to the optimization problem.

Abstract: An adjusting method for stabilizing optical characteristic parameters applicable to transmitter optical subassemblies with silicon photonic chips is provided.

Abstract: An electro-optic system, the electro-optic system that may include an input port that is configured to receive a bandpass signal that conveys information; wherein the bandpass signal is a radio frequency (RF) signal; an optical carrier source that is configured to generate an optical carrier signal having an optical carrier frequency; at least one electrical bias circuit that is configured to generate at least one electrical bias signal; an electro-optic modulation circuit that is linear at the optical field; a manipulator that is configured to (a) receive the at least one electrical bias signal and the bandpass signal, (b) generate, based on the at least one electrical bias signal and the bandpass signal, at least one modulating signal; wherein the electro-optic modulation circuit is configured to modulate the optical carrier by the at least one modulating signal to provide an output optical signal that comprises at least one optical pilot tone and at least one optical sideband that conveys the information.

Abstract: Part of compensation of the transmission characteristics of the optical transmitter is performed by transmitter compensation circuitry disposed at a stage prior to the optical transmitter. Remaining part of compensation of the transmission characteristics of the optical transmitter and compensation of the transmission characteristics of the optical receiver is performed by a receiver compensation circuitry disposed at a stage subsequent to the optical receiver. Transmitter compensation characteristics of the transmitter compensation circuitry is set so that a peak-to-average-power ratio of an output signal from the transmitter compensation circuitry becomes equal to or smaller than a predetermined value.

Abstract: An optical transmitter includes a Mach-Zehnder modulator having an arm waveguide and a phase controller configured to control a phase of a light propagating through the arm waveguide by applying a voltage to the Mach-Zehnder modulator. When the voltage is deviated from a predetermined range, the phase controller shifts the voltage in the direction opposite to a direction of the deviation from the predetermined range by the amount corresponding to a change of 2? in the phase.

Abstract: Techniques for transmitting an optical signal through optical fiber with an improved cost effective stimulated Brillouin scattering (SBS) suppression include externally modulating a light beam emitted from a light source with a high frequency signal. The light beam is also modulated externally with an RF information-carrying signal. The high frequency signals are at least twice a highest frequency of the RF signal. The high frequency signals modulating the light source can be gain and phase adjusted by the first set of gain and phase control circuit to achieve a targeted spectrum shape. The adjusted high frequency signals then are split, providing a portion of the split signals to modulate the light source and another portion of the split signals to the second set of phase and gain control circuit for adjusting a phase/gain.

Abstract: Upon receiving a communications signal conveying symbols at a symbol period T, a receiver applies filter coefficients to a digital representation of the communications signal, thereby generating filtered signals having a shape in the frequency domain characterized by a bandwidth expansion factor ?, where components of the filtered signals correspond to angular frequencies ? = - ? ? ( 1 + ? ) T ? ? … - ? ? ( 1 - ? ) T , + ? ? ( 1 - ? ) T ? ? … + ? ? ( 1 + ? ) T . The receiver calculates first-order components from a first phase derivative of the components at a first differential distance, second-order components from a second phase derivative of the first-order components at a second differential distance, and composite second-order components from an average of the second-order components over multiple time intervals.

Abstract: To provide an optical transmitter and an optical transmission method that can maintain the quality of an optical output signal in a wide wavelength range, an optical transmitter comprises: an optical modulator that includes an electrode and outputs an optical output signal obtained by modulating input light according to a drive signal applied to the electrode; a driver circuit that generates a drive signal and is connected to the optical modulator to apply a drive signal to one end of the electrode; a first element that is connected to the other end of the electrode and terminates the drive signal; and a controller that sets a first resistance value of the first element and a drive amplitude of the drive signal.

Abstract: An optical wireless communication system includes an optical wireless transmitter configured to emit a discrete-time signal of first light, second light, and third light having different wavelength spectra; and a light-receiving sensor including an optical wireless receiver including first, second, and third photoelectric conversion devices configured to convert discrete-time signals of the first, second, and third light beams into first, second, and third photoelectric conversion signals, respectively, wherein the second photoelectric conversion device at least partially overlaps the first photoelectric conversion device, and the third photoelectric conversion device at least partially overlaps at least one photoelectric conversion device of the first photoelectric conversion device or the second photoelectric conversion device, and at least one photoelectric conversion device of the first photoelectric conversion device, the second photoelectric conversion device, or the third photoelectric conversion devic

Abstract: A novel transmitter is proposed that provides broadband all-optical linearization of a Mach-Zehnder interferometer (MZI) modulator for use in high linearity RF photonic links and optical up-converter and down-converter schemes. It is based on an amplitude modulated (AM) MZI modulator where part of the laser Carrier is passed around the MZI modulator and added back to the AM signal, creating a Controlled Carrier-AM (CC-AM) signal. In this new scheme, a dual output MZI modulator is utilized, and the alternative output (Carrier*) is used together with the Carrier from the laser to create a new signal, LO*, which when coherently combined with the AM signal can reduce or completely cancel its 3rd order intermodulation distortion.

Abstract: Device, methods and systems for the electronic demodulation of optically phase demodulated signals are described. An example optical local oscillator generator configured to generate a radio frequency (RF) tone at a desired RF frequency includes a first input configured to receive a broadband optical pulse train, a second input coupled to a delay line interferometer to receive a first control voltage for controlling a delay value of the interferometer and to produce an output optical pulse train, a dispersive element, coupled to the delay line interferometer, to map the output optical pulse train to a time-domain modulated optical pulse train, an optical-to-electrical converter, coupled to the dispersive element, to convert the time-domain modulated optical pulse train to an analog electrical signal, and an RF filter, coupled to the optical-to-electrical converter, to filter the analog electrical signal to generate the RF tone at the desired RF frequency.

Abstract: An optical transmission apparatus includes a modulation unit that generates modulated light by modulating light while bias on which a low-frequency signal is superimposed is applied thereto; an optical amplification unit that generates amplified light by amplifying the modulated light while holding an intensity of the amplified light at a changeable target value; an optical detection unit that generates an electric signal by performing photoelectric conversion on a part of the amplified light; an amplification unit that amplifies the electric signal while suppressing variation in the amplified electric signal, the variation being due to a change of the target value; and a control unit that detects a low-frequency component from the amplified electric signal the variation of which is suppressed and controls the bias on a basis of the detected low-frequency component, the low-frequency component being generated by the low-frequency signal.

Abstract: An electro-optic system, the electro-optic system that may include an input port that is configured to receive a bandpass signal that conveys information; wherein the bandpass signal is a radio frequency (RF) signal; an optical carrier source that is configured to generate an optical carrier signal having an optical carrier frequency; at least one electrical bias circuit that is configured to generate at least one electrical bias signal; an electro-optic modulation circuit that is linear at the optical field; a manipulator that is configured to (a) receive the at least one electrical bias signal and the bandpass signal, (b) generate, based on the at least one electrical bias signal and the bandpass signal, at least one modulating signal; wherein the electro-optic modulation circuit is configured to modulate the optical carrier by the at least one modulating signal to provide an output optical signal that comprises at least one optical pilot tone and at least one optical sideband that conveys the information.

Abstract: A photonic N-to-one single-mode combiner is disclosed. In embodiments, the combiner receives multiple single-mode photonic inputs (e.g., via single-mode optical fibers) and combines the single-mode inputs into a multi-mode photonic output via photonic lantern. The multi-mode photonic output is converted via high-power, high-speed photodiode into an RF/electrical output which in turn drives an electro-optical modulator, modulating a second optical beam (e.g., a laser generated by a laser emitter of the combiner) to generate a single-mode photonic output signal.

Abstract: The present invention relates to telecommunication techniques and integrated circuit (IC) devices. More specifically, embodiments of the present invention provide an off-quadrature modulation system. Once an off-quadrature modulation position is determined, a ratio between DC power transfer amplitude and dither tone amplitude for a modulator is as a control loop target to stabilize off-quadrature modulation. DC power transfer amplitude is obtained by measuring and sampling the output of an optical modulator. Dither tone amplitude is obtained by measuring and sampling the modulator output and performing calculation using the optical modulator output values and corresponding dither tone values. There are other embodiments as well.

Abstract: A high data rate, high sensitivity, low power optical link using low-bandwidth components and low-bandwidth E/O drivers and receivers and method of building same. The method is based on the idea of making the optical part of the link look like a bandwidth limited lossy electrical channel, so that the powerful equalization methods used in the wireline electrical links can be applied to recover the transmitted data in a situation with low bandwidth and/or high loss and strong inter-symbol interference. Linear and non-linear optical channel components, E/O drivers and receivers can benefit from the apparatus and the methods of the invention.

Abstract: An optical transmitter includes: an optical modulator, a phase adjustment circuit, first and second synchronization circuits, and first and second drive circuits. The optical modulator includes a first modulation area and a second modulation area that is provided at output side of the first modulation area. The phase adjustment circuit adjusts a phase of a first clock signal so as to generate a second clock signal. The first and second synchronization circuits respectively output first and second electric signals in synchronization with the first and second clock signals. The first and second drive circuits respectively drive the first and second modulation areas with the first and second electric signals.

Abstract: The present invention relates to telecommunication techniques and integrated circuit (IC) devices. More specifically, embodiments of the present invention provide an off-quadrature modulation system. Once an off-quadrature modulation position is determined, a ratio between DC power transfer amplitude and dither tone amplitude for a modulator is as a control loop target to stabilize off-quadrature modulation. DC power transfer amplitude is obtained by measuring and sampling the output of an optical modulator. Dither tone amplitude is obtained by measuring and sampling the modulator output and performing calculation using the optical modulator output values and corresponding dither tone values. There are other embodiments as well.

Abstract: An optical transmission device includes: a first receiver that receives a first optical signal transmitted by a first sub carrier included in a super channel; a second receiver that receives a second optical signal transmitted by a second sub carrier included in the super channel; and an optical delay device that delays the first optical signal, based on path lengths of respective transmission paths along which the first optical signal and the second optical signal are transmitted.

Abstract: There is provided a transmission apparatus includes: a first modulator configured to modulate a first electrical signal to a second electrical signal that is a multicarrier signal including a plurality of subcarriers to which transmission capacities are allocated, respectively; a light source configured to generate light having a predetermined wavelength; a second modulator configured to modulate the light generated by the light source to an optical signal, based on the second electrical signal modulated by the first modulator; and a processor configured to: measure a first frequency distribution of intensity of the second electrical signal modulated by the first modulator, measure a second frequency distribution of intensity of the optical signal modulated by the second modulator, compare the first frequency distribution and the second frequency distribution, and control modulation characteristics of the second modulator according to a result of comparing the first frequency distribution and the second frequ

Abstract: Provided are methods and systems for receiving and processing optical signals are provided. A dual single side band (SSB) modulation scheme is utilized to take advantage of given wavelengths' bandwidth. Modulation schemes are employed that modulate each SSB with their In-phase (I) and Quadrature (Q) components. The methods and systems discussed perform MIMO de-multiplexing algorithms to remove any imaging components of the left and right SSBs provided by the modulators. Various algorithms can be employed, including but not limited to inserting time interleaved training sequences into the channels of the right and left SSB signals or by employing a constant-modulus-algorithm (CMA) de-multiplexing.

Abstract: An optical transmission device includes an optical modulator and a processor. The optical modulator optically modulates an optical signal with a driving signal to output a modulated optical signal. The processor performs ABC on a bias of the optical modulator, using the modulated optical signal, so as to cause the bias to converge to an optimum point. The processor starts the ABC using a modulated optical signal optically modulated with a QPSK signal at start-up timing, acquires an optimum value that is a bias value when the bias converges to the optimum point, and stops the ABC. After the ABC is stopped, the processor sets the acquired optimum value as an initial value, and restarts the ABC using a modulated optical signal optically modulated with an N-QPSK signal.

Abstract: An optical transmitter includes a discrete multi-tone (DMT) modulation unit that modulates a carrier signal having a specific frequency with an information signal and a carrier signal having a frequency different from the specific frequency with a monitor signal, to generate a DMT modulation signal that multiplexes the information signal and the monitor signal. The optical transmitter includes a laser diode (LD) unit that optically converts the DMT modulation signal to a corresponding optical DMT modulation signal, a frequency extraction unit that extracts a harmonic distortion component of the monitor signal from the optical DMT modulation signal, and a frequency analysis unit. The optical transmitter includes a bias control unit that controls a bias supply unit that adjusts a bias value to be supplied to the LD unit such that the extracted harmonic distortion component of the monitor signal is reduced.

Abstract: A distributed traveling-wave Mach-Zehnder modulator driver having a plurality of modulation stages that operate cooperatively (in-phase) to provide a signal suitable for use in a 100 Gb/s optical fiber transmitter at power levels that are compatible with conventional semiconductor devices and conventional semiconductor processing is described.

Abstract: The present invention relates to telecommunication techniques and integrated circuit (IC) devices. More specifically, embodiments of the present invention provide an off-quadrature modulation system. Once an off-quadrature modulation position is determined, a ratio between DC power transfer amplitude and dither tone amplitude for a modulator is as a control loop target to stabilize off-quadrature modulation. DC power transfer amplitude is obtained by measuring and sampling the output of an optical modulator. Dither tone amplitude is obtained by measuring and sampling the modulator output and performing calculation using the optical modulator output values and corresponding dither tone values. There are other embodiments as well.

Abstract: A system and method for adaptive equalization in a communication system. The system can include a modulator, a processor coupled to the modulator, and a memory coupled to the processor. The memory can store software instructions that, when executed by the processor, cause the processor to perform operations that can include generating, for each of one or more scan frequencies of interest, an optimal bias setting of the modulator. Data indicating a selection of a range of frequencies to be processed by the communication system can be received at the processor. The operations can include determining, responsive to the receiving, the optimal bias setting corresponding to the selected range of frequencies. A bias of the modulator can be adjusted based on the determined optimal bias setting, the adjusting providing adaptive equalization of the flatness response of the communication system.

Abstract: A high data rate, high sensitivity, low power optical link using low-bandwidth components and low-bandwidth E/O drivers and receivers and method of building same. The method is based on the idea of making the optical part of the link look like a bandwidth limited lossy electrical channel, so that the powerful equalization methods used in the wireline electrical links can be applied to recover the transmitted data in a situation with low bandwidth and/or high loss and strong inter-symbol interference. Linear and non-linear optical channel components, E/O drivers and receivers can benefit from the apparatus and the methods of the invention.

Abstract: An optical phase shifter includes an optical waveguide, a plurality of partial phase shifting elements arranged sequentially, and control circuitry electrically coupled to the partial phase shifting elements. The control circuitry is adapted to provide an activating signal to each of the N partial phase shifting elements such that the signal is delayed by a clock cycle between adjacent partial phase shifting elements in the sequence. The transit time for a guided optical pulse train between the input edges of consecutive partial phase shifting elements in the sequence is arranged to be equal to a clock cycle, thereby enabling pipelined processing of the optical pulses.

Abstract: A multi-channel transceiver using a floating frequency grid for multi-channel, optical communication is presented. Transmitter frequencies are permitted to drift, and a receiver is tuned to compensate for drifts in the transmitter frequencies.

Abstract: A system includes an optical power meter operable to generate an optical power signal corresponding to the optical power of a received output signal generated by an optical IQ-modulator. The system further includes a processor operable to receive the optical power signal and determine, based on a minimization algorithm and the received optical power signal, a first bias voltage to be applied to a first sub-modulator of the optical IQ-modulator and a second bias voltage to be applied to a second sub-modulator of the optical IQ-modulator. The system may also include a peak power meter operable to generate a peak power signal corresponding to the peak power of the received output signal generated by the optical IQ-modulator, wherein the processor is further operable to determine, based on a minimization algorithm and the received peak power signal, a third bias voltage to be applied to a phase shift component of the optical IQ-modulator.

Abstract: A transmitter and a receiver for reducing power consumption in a frequency modulation-ultra-wideband (FM-UWB) communication system are provided. The transmitter includes a detector configured to generate a pulse signal when an edge of a digital signal is detected. The transmitter further includes a first modulator configured to modulate the digital signal into a first modulation signal based on a value of the digital signal. The transmitter further includes a second modulator configured to modulate the first modulation signal into a second modulation signal based on a frequency of the first modulation signal when the pulse signal is generated.

Abstract: An optical modulator includes main input and output ports; first and second Mach-Zehnder modulators; a first branching waveguide optically coupling the main input port to the first and second Mach-Zehnder modulators; a first driver circuit connected to the first Mach-Zehnder modulator, the first driver circuit generating a first drive signal having a first amplitude at a first bias point; and a second driver circuit connected to the second Mach-Zehnder modulator, the second driver circuit generating a second drive signal having a second amplitude at a second bias point. The first and second drive signals satisfy at least one of a first condition and a second condition. The first condition is that the first amplitude differs from the second amplitude. The second condition is that the first bias point differs from the second bias point.

Abstract: An optical transmitter includes: an optical modulator including a first modulation unit and a second modulation unit respectively configured to propagate a first optical signal and a second optical signal that are obtained by splitting input light; a signal generator configured to generate a first drive signal and a second drive signal that are respectively supplied to the first modulation unit and the second modulation unit; a phase controller configured to control a phase difference between the first optical signal and the second optical signal in the optical modulator; and a phase difference detector configured to detect the phase difference between the first optical signal and the second optical signal controlled by the phase controller. The signal generator generates the first drive signal and the second drive signal based on the phase difference detected by the phase difference detector.

Abstract: A method of controlling an optical transmitter having a Dual Parallel Mach-Zehnder (DPMZ) modulator. An I-Q power balance between respective branches of the DPMZ modulator is detected, and at least one parameter of the DPMZ modulator is adjusted to drive the I-Q power balance to a predetermined target value. An optical transmitter may have Quad Parallel Mach-Zehnder (QPMZ) modulator having a pair of parallel DPMZ modulators for modulating respective X- and Y-polarization lights. In such cases, an X-Y power imbalance between the two polarization lights is detected, and at least one parameter of the QPMZ modulator is adjusted to drive the X-Y power imbalance to a predetermined value.

Abstract: A method to control an optical transceiver, in particular, to drive an LD installed within the optical transceiver is described. The LD in the bias current thereof is determined by the automatic power control (APC) loop to keep an average of the optical output power. The modulation current is determined by a feedback loop to keep the extinction ratio (ER) in a preset range. The initial condition of the modulation current for the feedback loop is set by T-Im characteristic. The T-Im characteristic is first derived based on data measured in a status of the LD not installed in the transceiver. The T-Im characteristic is revised timely by the modulation current practically obtained for the optical transceiver.

Abstract: A signal transmission device drives a light-emitting element and outputs an optical signal depending on a data signal from an electronic device. The device includes an element driving portion which supplies a driving current to the light-emitting element, wherein the driving current is obtained by superimposing a modulation current on a bias current, the modulation current being dependent on the data signal indicating emitting information of the light-emitting element. A temperature compensation portion of the device controls the bias current and the modulation current depending on the temperature so that a temperature-current characteristic of the light-emitting element is reproduced based on the voltage which is dependent on the temperature and the voltage which is independent from the temperature, thereby performing current control depending on the temperature.

Abstract: After a startup of an optical transmitter, a control is started in such a way that a modulation amplitude of a driving signal of a phase modulator is set as 0, and that an operational point of a bias voltage is set as the lowest point of light transmission characteristics of the phase modulator. When the operational point of the bias voltage reaches the lowest point, the modulation amplitude of the driving signal is gradually increased from 0 to 2V?.

Abstract: An optical signal transmitter of the present invention includes: two phase modulating portions; a phase shifter which displaces carrier phases of two output lights from the phase modulating portions by ?/2; a multiplexing portion which multiplexes two signal lights, carrier phases of the two signal lights being made orthogonal to each other by the phase shifter; a drive signal electrode portion which supplies a differential data signal to each of four paths of interference optical waveguides, each of the two phase modulating portions having the interference optical waveguides, the differential data signal having an amplitude which is equal to a half-wave voltage V? of the two phase modulating portions; a drive amplifier which amplifies the differential data signal to be supplied to each of the four paths of the interference optical waveguides; a data bias electrode portion which supplies a total of four data bias voltages to two arms, each of the two phase modulating portions having the two arms; an orthogona

Abstract: An optical transmitter includes an optical modulator having first and second waveguides to modulate carrier light at each of the waveguides using a driving signal with 2*n intensity levels (n is an integer 1 or greater); and a phase shifter to cause a phase difference between a first optical signal and a second optical signal output from the first waveguide and the second waveguide, respectively. A photodetector converts a portion of a multilevel optical modulation signal acquired by combining the first optical signal and the second optical signals into an electrical signal. A monitor detects a change in an alternating current component in the detected modulation signal. A controller controls at least one of a first bias voltage and a second bias voltage being supplied to the first waveguide and the second waveguide, respectively, so as to increase the power value of the alternating current component.

Abstract: The optical frequency comb generating device having two optical modulation parts 41 and 42 independently modulating optical waves propagating in two branch waveguides and a phase regulator 43 controlling a phase difference between the optical waves includes amplitude adjusting means 22 for adjusting a voltage amplitude of the RF signal supplied to at least one of the optical modulation parts, monitoring means 21 for monitoring the intensity Pout of the output light beam, and a bias control circuit 20 that controls the amplitude adjusting means to change a difference in voltage amplitude between the RF signals supplied to each optical modulation part, that detects a variation of the output light beam corresponding to the variation of the difference in voltage amplitude from the output signal of the monitoring means, and that controls the phase regulator on the basis of the detection result to adjust the phase difference.

Abstract: A modular hub driver architecture may include a multi-delay block configured to provide an enhanced delay match among N distinct stages of a distributed modulating electro-optical interface core. The electro-optical multi-core modulator driver may include an input impedance matching stage and a pre-conditioning circuit configured to generate a number M, an integer divisor of N, of delayed replicas of an electrical modulating signal. The electro-optical multi-core modulator may include an array of M launch buffers of the replica signals, and an array of M multi-delay blocks, each including delay circuit modules differently cascaded on distinct signal paths, and configured to receive, at respective inputs, the M replica signals and to output N/M differently delayed replicas of the input signals, each driving a correspondent output stage of one on the N electro-optical interface cores.

Abstract: A modulating apparatus includes a branch that branches input light; a first modulating unit that modulates the phase of a first branch obtained by the branch; a second modulating unit that modulates a second branch obtained by the branch; a third modulating unit that is connected in series to the first modulating unit, transmits the first branch without branching the first branch, modulates the phase of light transmitted by controlling a refractive index of the light transmitted; a fourth modulating unit that is connected in series to the second modulating unit, transmits the second branch without branching the second branch, and modulates the phase of a light transmitted by controlling a refractive index of the light transmitted; and a coupler that couples the first branch modulated by the first and the third modulating units and the second branch modulated by the second and the fourth modulating units, at different intensities.

Abstract: The present invention provides a method and an apparatus for controlling a phase delay offset point of a modulator. The method comprises: acquiring backlight detection current signals output from a modulator in different working states, and determining harmonic amplitude values of the backlight detection current signals corresponding to the different working states; determining a detection value of a phase delay offset point corresponding to the modulator according to the determined harmonic amplitude values; comparing the detection value with a set target value of the phase delay offset point, and controlling a position of the phase delay offset point corresponding to the modulator according to the comparison result. The accuracy of controlling the position of the phase delay offset point of the modulator and the performance of the Differential Quadrature Phase Shift Keying (DQPSK) modulation system are improved through the technical solution.

Abstract: An optical communication module includes a laser that emits laser light, and an electro-absorber that absorbs the laser light, which is emitted from the laser, according to a voltage modulated based on a modulating signal and a bias voltage. The optical communication module detects data that varies correlatively with the temperature of the electro-absorber, and sets the bias voltage, which is associated with the detected data, on the basis of relational data specifying at least the relationship between the bias voltage and the data.

Abstract: A method of operating an optical amplifier includes determining a gain of the optical amplifier and providing a modulator drive signal to an optical signal source. The modulator drive signal is a function of the gain of the optical amplifier. The method also includes producing an input optical signal using the optical signal source. The input optical signal includes a first plurality of pulses, each of the first plurality of pulses having an amplitude related to the modulator drive signal. The method further includes coupling the input optical signal to the optical amplifier and amplifying the input optical signal using the optical amplifier to produce an output optical signal including a second plurality of pulses.