Abstract: A communications device may include a remote device having a first E/O modulator to modulate an optical carrier signal with an input signal having a first frequency, an optical waveguide coupled to the remote device, and a local device coupled to the optical waveguide. The local device may include an optical source to generate the optical carrier signal, a second E/O modulator to modulate the optical carrier signal with a reference signal to generate a modulated reference signal, an OIL source coupled to the second E/O modulator and to amplify the modulated reference signal, and an O/E converter coupled to the OIL source and to generate an output signal including a replica of the input signal at a second frequency based upon the reference signal.

Abstract: An optical transmitter has an electrical signal generator configured to generate an electrical drive signal based upon input data; an optical modulator configured to modulate an input light by the electrical drive signal, the optical modulator having a first waveguide pair, a second waveguide pair, and a phase shifter that provides a phase difference between light waves travelling through the first waveguide pair and the second waveguide pair; and a controller configured to set the phase difference at the phase shifter to 0+n*? radians, where it is an integer, when a modulation scheme of the optical modulator is changed from a first scheme using four or more phase values to a second scheme using two phase values.

Abstract: A method and an apparatus are provided, for monitoring OSNR system margin in optical networks, by relying on relationships that exists between the Optical Signal to Noise Ratio (OSNR) value and the Electrical Signal to Noise Ratio (ESNR) value.

Abstract: Adaptive communications focal plane arrays that may be implemented in, e.g., a specially-configured camera that can be utilized to receive and/or process information in the form of optical beams are presented. A specialized focal plane array (FPA) having a plurality of optical detectors is utilized, where one or more optical detectors are suppressed such that data is not allowed to be output from the one or more suppressed optical detectors, and only a significantly smaller number or subset of optical detectors receiving optical beams are allowed to output data. In this way, the rate at which data is to be output by an adaptive communications FPA (ACFPA) can be significantly reduced.

Abstract: An apparatus includes: a laser driver configured to output a laser diode current in accordance with a transmit data, a bias control code, and a modulation control code, a laser diode configured to receive the laser diode current and output a light signal, a photodiode configured to receive the light signal and output a photodiode current, a reference driver configured to output a reference current in accordance with the transmit data, the transmit enable signal, a reference bias code, and a reference modulation code, a two-fold comparison circuit configured to compare the photodiode current and the reference current and output a first decision and a second decision, and a DSP configured to adjust the bias control code and the modulation control code in accordance with the first decision and a second decision. A method provides reliable light output using the described apparatus.

Abstract: This disclosure relates to wavelength division multiplexed (WDM) passive optical networks (PON), and the transmission of point-to-point and broadcast or multicast channels from an optical line transmitter (OLT) to an optical network unit (ONU).

Abstract: A method and an apparatus for self-calibration of an ONU receiver in a multi-wavelength PON system, said method including the initial physical layer scan of the receiver tuning range, distributed estimation of the down-stream wavelength channel drift with respect to the nominal standard-based wavelengths, and reporting the estimated downstream wavelength channel drift in the downstream Channel_Map message.

Abstract: This disclosure provides methods, systems, and devices for communication of authentication information in an access control system. The authentication information may be transmitted to an electronic locking device configured to restrict access to an entry point of the access control system. In various embodiments, a smart device comprises a light-emitting diode (LED) and a wireless networking radio for exchanging access control information with a remote server. The smart device may receive information from the remote server that configures the LED to present authentication information as an optical signal. The electronic locking device may comprise a photodetector arranged to confront a user holding the smart device so as to receive an optical signal emitted by the smart device. According to various embodiments, the electronic locking device may be configured to respond to the authentication information conveyed by the optical signal by unlocking the entry point.

Abstract: An optical transmitter includes an optical modulator that is driven by a driving signal, an acquisition part, and a controller. The acquisition part obtains a relationship between a fluctuation of a parameter to adjust the driving signal and a fluctuation of a state of output light from the optical modulator due to the fluctuation of the parameter. The controller controls an amplitude of the driving signal on the basis of the obtained relationship.

Abstract: An apparatus comprising a digital signal processor (DSP) unit configured to perform fiber dispersion pre-compensation on a digital signal sequence based on a dispersion value to produce a pre-compensated signal, wherein the dispersion value is associated with a remote optical receiver, a plurality of digital-to-analog converters (DACs) coupled to the DSP unit and configured to convert the pre-compensated signal into analog electrical signals, and a frontend coupled to the DACs and configured to convert the analog electrical signals into a first optical signal, adding a constant optical electric (E)-field to the first optical signal to produce a second optical signal, and transmit the second optical signal to the remote optical receiver.

Abstract: Optical transmission systems and methods are disclosed that utilize a QSM optical fiber with a large effective area and that supports only two modes, namely the fundamental mode and one higher-order mode. The optical transmission system includes a transmitter and a receiver optically coupled by an optical fiber link that includes at least one section of the QSM optical fiber. Transmission over optical fiber link gives rise to MPI, which is mitigated using a digital signal processor. The QSM optical fiber is designed to have an amount of DMA that allows for the digital signal processor to have reduced complexity as reflected by a reduced number of filter taps as compared to if the DMA were zero.

Abstract: A wavelength and bandwidth allocation method which includes in order a wavelength determination step S4 of determining a plurality of wavelengths of an uplink signal from each ONU to OLT to guarantee a guaranteed bandwidth corresponding to a subscription service class of each ONU and a reference bandwidth distribution step S5 of distributing, as reference bandwidths, all bandwidths of the plurality of wavelengths determined in the wavelength determination step S4 to each ONU according to the subscription service class of each ONU and making the reference bandwidths of ONUs whose subscription service classes are the same be the same.

Abstract: An optical transceiver comprises a transmitter configured to transmit a first signal, and a receiver coupled to the transmitter and configured to receive a first compensation, wherein the first compensation is based on a pattern-dependent analysis of the first signal, and provide the first compensation to the transmitter, wherein the transmitter is further configured to compensate a second signal based on the first compensation to form a first compensated signal, and transmit the first compensated signal. An optical transmitter comprises a digital signal processor (DSP) comprising a compensator, a digital-to-analog converter (DAC) coupled to the DSP, a radio frequency amplifier (RFA) coupled to the DAC, and an electrical-to-optical converter (EOC) coupled to the RFA. An optical receiver comprises an optical-to-electrical converter (OEC), an analog-to-digital converter (ADC) coupled to the OEC, and a digital signal processor (DSP) coupled to the ADC and comprising a calibrator.

Abstract: An optical communication system provides coherent optical transmission for metro applications. Relative to conventional solutions, the optical communication system can be implemented with reduced cost and can operate with reduced power consumption, while maintaining high data rate performance (e.g., 100 G). Furthermore, a programmable transceiver enables compatibility with a range of different types of optical networks having varying performance and power tradeoffs. In one embodiment, the optical communication system uses 100 Gb/s dual-polarization 16-point quadrature amplitude modulation (DP-16QAM) with non-linear pre-compensation of Indium Phosphide (InP) optics for low power consumption.

Abstract: A data carrier 2 is provided with a comparator 41, a capacitor 42, a comparator operation adjustment resistor 43, a resistance voltage divider circuit 44 and a reactive-current resistor 45. The capacitor 42 is disposed between the cathode of a photo-diode (PD) 21 and the minus input terminal of the comparator 41. The comparator operation adjustment resistor 43 is disposed between the plus terminal of a primary battery 271 and the minus input terminal of the comparator 41. The resistance voltage divider circuit 44 is constituted by a series connection of voltage dividing resistors 441 and 442. One end of the resistance voltage divider circuit 44 is connected to the plus terminal of the primary battery 271. The junction between the voltage division resistor 441 and the other voltage division resistor 442 is connected to the plus input terminal of the comparator 41.

Abstract: The invention describes a method and an arrangement for transmitting an optical transmission signal with reduced polarization-dependent loss. A first transmission signal component and a second orthogonal transmission signal component of the optical transmission signal are transmitted with a time difference between said transmission signal components.

Abstract: A system, method, and device for RF upconversion. The system can include a laser, two EAMs, a photonic filter, a photonic service filter, two photodiodes, and a mixer. The first EAM can convert a received RF signal into the photonic domain by modulating an optical signal (received from the laser) based on the received RF signal to output a modulated optical signal. The photonic filter can output a filtered optical signal based on the modulated optical signal to the first photodiode which can output a filtered RF signal in the RF domain. The second EAM can output an LO modulated optical signal based on a received LO to the service filter which can output a filtered LO optical signal to the second photodiode which can output a filtered LO signal in the RF domain. The mixer can mix the filtered RF and LO signals to generate an IF signal.

Abstract: An excitation light source device includes: an excitation light source to generate the Raman excitation light; a light source controller to control an intensity of the Raman excitation light; an amplified spontaneous emission noise measurer to measure an intensity of amplified spontaneous emission noise caused by the Raman excitation light; and a transmission line abnormality analyzer to detect abnormality in the transmission line on a basis of a control state of the light source controller and a measurement result of the amplified spontaneous emission noise measurer. In a state where the abnormality is not detected, the light source controller controls the intensity of the Raman excitation light to gradually increase to a set value. In a state where the abnormality is detected, the light source controller controls the excitation light source to stop or reduce generation of the Raman excitation light.

Abstract: An optical signal output apparatus includes: a switch having a first state or a second state in accordance with user's operation; and an optical signal output section that outputs a low-level optical signal when the switch is in the first state, whereas outputting a high-level optical signal when the switch is in the second state.

Abstract: A laser relay module in a free space optical communication network includes: a beacon source for generating an optical beacon signal for aligning a communication channel of a source optical node to a communication channel of a receiving optical node; a beacon inserter for encoding the optical beacon signal with switching information; a telescope for transmitting the encoded optical beacon signal to the receiving optical node; a beacon detector for detecting received switching information from the modulated optical beacon signal, wherein the receiving optical node uses the encoded optical beacon signal to align communication channel of the receiving optical node with communication channel of the source optical node; and a processor for using the detected switching information to change configuration of an optical switch matrix to direct received data to a next optical node in the free space optical communication network.