Abstract: The deep penetration of optical transmission from the very edges of the network with optical access networks to the very core with routing data within data centers before transmission has resulted in competing demands for increased functionality, reduced cost, enhanced manufacturability, and reduced footprint. At the same time monitoring and fault detection with prior art optical time domain reflectometry systems have not kept up to the demands of these networks and systems as they are expensive test equipment based solutions. It would be beneficial to provide embedded OTDR functionality within each transmitter, receiver or transceiver deployed within the network allowing every link to be monitored continuously. It would be further beneficial for such embedded OTDRs to meet the demands for lower cost, high volumes, and smaller footprints with enhanced manufacturability.

Abstract: A station-side device performs transmission and reception of an optical signal to and from a subscriber-side device, and includes a communication control unit configured to perform optical signal communication using a plurality of wavelengths by wavelength division multiplexing and time division multiplexing; and a registration unit configured to set an acceptance period in at least one wavelength among the plurality of wavelengths, to perform a new registration of a subscriber-side device in response to a registration request of the subscriber-side device received within the acceptance period, and not to set the acceptance period in at least one other wavelength among the plurality of wavelengths.

Abstract: An optical receiver, used in wavelength-division multiplexing, has multiple photodetectors per channel. The optical receiver comprises a demultiplexer to separate incoming light into different output waveguides, one output waveguide for each channel. A splitter is used in each output waveguide to split each output waveguide into two or more branches. A separate photodetector is coupled with each branch so that two or more photodetectors are used to measure each channel.

Abstract: Examples disclosed herein relate to optical driver circuits. In some of the disclosed examples, an optical driver circuit includes a pre-driver circuit and a main driver circuit. The pre-driver circuit may include a pattern generator and at least one serializer to generate a main modulation signal and an inverted delayed modulation signal. The main driver circuit may include a level controller to control amplitudes of pre-emphasis on rising and falling edges of a modulation signal output and an equalization controller to transition the modulation signal output from the pre-emphasis amplitudes to main modulation amplitudes using the inverted delayed modulation signal.

Abstract: Provided are methods and systems for improved user tracking via the exchange of information over narrow-beam infrared (IR) transmission. IR receivers are positioned around a venue. A limited-range, narrow-beam IR transmitter associated with a user sends IR signals that are received by the IR receiver when the IR transmitter is close enough to the receiver. The receiver then transmits signal data from the received signal to a back-end location tracking system (LTS) that aggregates and processes the received signal data as a detection event. Based on the detection event, the LTS determines the location of the IR receiver hence the location of the user. Because of the limited transmission range of the IR transmitter, analyzing the detection event allows precise determination of the user's location, orientation, and/or movements within the venue. The LTS can also determine the identity of the user.

Abstract: Techniques are disclosed for augmenting light-based communication (LCom) receiver positioning using, for example, an inertial navigation system (INS). An LCom receiver INS may utilize one or more on-board accelerometers and gyroscopic sensors to calculate, via dead reckoning, the position, orientation, and velocity of the receiver. In this manner, the receiver can calculate its relative position using the INS based on a reference point or location. In some cases, the receiver may also or alternatively determine its location or position using a global positioning system (GPS), Wi-Fi-based positioning system (WPS), or some other suitable positioning system. When no LCom signals are in the FOV of the receiver and/or the link is lost to other positioning systems, the receiver INS may be used to augment the receiver positioning. In some cases, the INS mode may run parallel to other positioning techniques to continuously calculate the relative position of the receiver.

Abstract: An electro-optic transceiver module, method of manufacturing, and method of transmitting signals are provided that allow multiple optical signals at different wavelengths (e.g., according to CWDM) to be combined for transmission via a number of optical fibers that is smaller than the number of electrical channels according to which the optical signals were generated. Thus, CWDM may be used in connection with lower-cost VCSEL technology (e.g., as opposed to higher-cost edge-emitting lasers) by providing for wavelength compensation at the VCSEL driver to offset any changes in wavelength that may have otherwise occurred at the VCSELs. In particular, a microcontroller of the electro-optic transceiver module correlates a monitored temperature of the VCSELs to an actual wavelength of the corresponding optical signals transmitted by the respective VCSELS and determined an adjustment in a current supplied by the VCSEL driver to each VCSEL to achieve more precise and consistent wavelengths at the VCSELs.

Abstract: Embodiments of a computing device and optical data switching circuitry are generally described herein. A processing element of the optical data switching circuitry may generate a plurality of optical data signals, and may send the optical data signals to an optical switch of the optical data switching circuitry. The optical switch may transmit the optical signals to a fiber optic router for relay to different destinations. The optical switch may switch between transmission directions for transmission of the optical signals to different receiving ports of the fiber optic router. The receiving ports of the fiber optic router may be mapped to the different destinations, in some cases.

Abstract: In conventional optical receivers the dynamic range is obtained by using variable gain amplifiers (VGA) with a fixed trans-impedance amplifier (TIA) gain. To overcome the SNR problems inherent in conventional receivers an improved optical receiver comprises an automatic gain control loop for generating at least one gain control signal for controlling gain of both the VGA and the TIA. Ideally, both the resistance and the gain of the TIA are controlled by a gain control signal.

Abstract: An apparatus and method for measuring frequency response characteristics of an optical transmitter and an optical receiver where the apparatus includes: a generating unit configured to generate a driving signal for driving the modulator of the optical transmitter, which comprises at least two frequencies; and a calculating unit configured to respectively calculate the frequency response characteristics of the optical transmitter and the optical receiver according to output signal components in output signals of the optical receiver corresponding to at least two detection signal components of identical amplitudes and different frequencies in detection signals. The frequency response characteristics of the optical transmitter and the optical receiver may be obtained, the amplitude responses and phase responses in the frequency response characteristics may be respectively obtained, and the measurement results are accurate and reliable.

Abstract: A laser communication system its integrated microradian-accuracy Acquisition and Tracking Sensor (ATS) to perform a celestial navigation fix to determine the attitude of the laser communications payload, including the integrated ATS and the co-boresighted laser beam, prior to establishing a laser communication link with a second vehicle such as a high-altitude aircraft or satellite. The laser communication system may use a legacy platform INS to initially point its narrow FOV ATS at one or more stars to obtain the vehicle's attitude therefrom. Then the precision payload attitude determined with the ATS star tracker fix is used to point the co-boresighted laser beam to establish a laser communications link with the second vehicle.

Abstract: A method for wireless data transmission between a first communication device and a second communication device, wherein the first communication device acts as a data source and the second communication device acts as a data sink, includes: splitting, by the data source, data to be transmitted from the data source to the data sink into a carrier signal for a radio channel and an optical carrier signal by modulating the carrier signals; transmitting the data via a hybrid transmission path from the data source to the data sink by simultaneously transmitting some of the data via the radio channel and some of the data via a wireless optical direct channel; and merging, by the data sink, via a demodulation process, the data transmitted via the radio channel and the data transmitted via the wireless optical direct channel.

Abstract: The disclosure discloses a Chromatic Dispersion (CD) detection method for an optical transmission network. Data of two polarization states orthogonal to each other is converted from time-domain data to frequency-domain data, extraction is performed on the frequency-domain data and a linear combination operation is performed on the extracted frequency-domain data, an argument of a CD value of the data of the two polarization states are obtained according to a result of the linear combination operation, and the CD value is estimated according to the argument of the CD value of the data of the two polarization states. The disclosure further discloses a CD detection device for the optical transmission network and a storage medium.

Abstract: In some embodiments, an apparatus includes an optical transceiver that includes a first set of electrical transmitters operatively coupled to a switch. Each electrical transmitter from the first set of electrical transmitters is configured to transmit an electrical signal from a set of electrical signals. In such embodiments, the switch is configured to switch an electrical signal from the set of electrical signals such that the set of electrical signals are transmitted via a second set of electrical transmitters. Each electrical transmitter from the second set of electrical transmitters is operatively coupled to an optical transmitter from a set of optical transmitters. The set of optical transmitters is operatively coupled to an optical multiplexer. In such embodiments, at least one electrical transmitter from the second set of electrical transmitters is associated with a failure within the optical transceiver.

Abstract: The present disclosure provides a method and system of identifying macro-bends in at least one test fiber. The method includes generation of modulated optical pulses and scrambling the state of polarization of the modulated optical pulses to random states of polarization. The method includes injection of the modulated optical pulses in at least one test fiber and reception of backscattered optical pulses and splitting of the backscattered optical pulses to a first optical component and a second component. The method includes measurement of a first power of the first optical component and a second power of the second optical component of the backscattered optical pulses. The method includes calculation of discrete values of polarization dependent loss as a function of distance and identification of the macro-bends by analysis of peaks in one or more plots of one or more traces of the discrete values of the polarization dependent loss.

Abstract: A system monitors optical performance of an optical link within an optical network. The system includes an optical transmitter having an expanded-spectrum pilot-tone modulator for modulating an expanded-spectrum pilot tone onto a high-speed data signal to generate an expanded-spectrum optical signal and an optical receiver for receiving the expanded-spectrum optical signal and for detecting and decoding the expanded-spectrum pilot tone to enable monitoring of the optical performance of the optical link.

Abstract: Electrical-optical interface devices and methods for use in optical communications systems are disclosed. The electrical-optical interface devices are configured to convert electrical signals to optical signals and optical signals to electrical signals, and are configured to connect to external devices. The electrical-optical interface device is configured to monitor the data transmission between external devices over a primary communication pathway. The electrical-optical interface device is designed to reconfigure itself when it receives information about a communication error so that it automatically utilizes secondary optical communication pathways as redundant optical communication pathways to maintain data communication between the external devices.

Abstract: A multiport optical switch is used to controllably select a specific incoming optical signal that is to be processed by an associated optical channel monitor (OCM). The OCM includes a tunable optical filter and photodetector arrangement, and is configured to measure the optical spectrum of the incoming optical signal and extract information associated with the various optical channels forming the incoming optical signal (i.e., power, wavelength, OSNR, etc., per channel in the signal). The OCM also includes a processor that generates a pair of output control signals, a first signal to control the wavelength scanning process of the tunable optical filter and a second signal to control the setting of the multiport optical switch. The second signal may also be used to perform “detuning” of a selected input of the multiport optical switch, providing the ability to adjust the power level of an input signal prior to entering the OCM.

Abstract: A driver circuit for an optical transmitter includes a main path in parallel with an inverting path. The data signals from the main path and the inverting path can be combined to generate an output signal for a laser diode. The main path can communicate a data signal via a first transmission line and the inverting path can communicate an inverted data signal via a second transmission line. The second transmission line can be longer than the first transmission line in order to delay the inverted data signal. In addition, the inverted data signal can be weighted before being combined with the data signal from the main path.

Abstract: A communication interface apparatus can include a free-air optical transceiver for communicating signals at a first speed and an electrical contact for communicating at least one of: signals at a second speed or power. The communication interface can include a substrate having a plurality of electrical circuits. The optical transceiver can be electrically coupled to the substrate and configured to transceive an optical signal in free air. In an example, the optical transceiver can convert the optical signal to the signal at the first speed, such as an electrical signal. In an example, the electrical contact can be communicatively coupled to the substrate. The electrical contact and the free-air optical transceiver can be attached to the substrate in fixed relation with respect to one another.