Abstract: In some examples, fiber optic link intermittent fault detection and localization may include determining, for a fiber optic link that is to be analyzed, at least one section corresponding to the fiber optic link, at least one detection threshold corresponding to the at least one section, and a reference trace for the fiber optic link. A real-time trace may be acquired for the fiber optic link, and a comparison trace may be generated based on analysis of the reference trace and the real-time trace. Based on analysis of the at least one section to determine whether at least one comparison trace section level indicator determined from the comparison trace exceeds the at least one detection threshold, an event associated with the fiber optic link may be identified.

Abstract: An optical receiver is disclosed, including an optoelectronic detector, a transimpedance amplification (TIA) circuit, a single-ended-to-differential converter, an I/O interface, and a controller. The optoelectronic detector, having bandwidth lower than required system transmission bandwidth, converts an optical signal into a current signal. The TIA circuit compensate gain for the received current signal based on a received control signal, to obtain a voltage signal, where a frequency response value of the current signal within first bandwidth is greater than that within the bandwidth of the optoelectronic detector, and any frequency in the first bandwidth is not lower than an upper cut-off frequency of the optoelectronic detector. The single-ended-to-differential converter converts the voltage signal into a differential voltage signal. The I/O interface outputs the differential voltage signal. The controller generates the control signal based on the differential voltage signal.

Abstract: Embodiments of this application relate to the field of optical communications, and in particular, to a technology of processing data in an optical transport network. In a method for processing data, an optical network device extracts Ethernet data from a data frame of one path, converts the Ethernet data into another format, and places the Ethernet data converted into the another format into a data frame of another path. The optical network device is a destination device of the path and a source device of the another path. In addition, the optical network device further extracts overhead information from the data frame of the path, and inserts the overhead information into the data frame of the another path. The method for processing data provided in this application can implement interworking between different types of Ethernet interfaces. In addition, by using cross-path overhead processing, the method reduces path management complexity.

Abstract: Systems and methods are provided for re-calibrating an in-service Optical Multiplex Section (OMS) while it is operating in an optical system. A method, according to one implementation, includes a step of analyzing a state of at least one component of the in-service OMS in an optical network, whereby the at least component may include, among other things, one or more fiber spans. Based on a need to re-calibrate the at least one component of the OMS, the method also includes the step of transitioning the OMS from an in-service mode to a maintenance mode to prepare the OMS for re-calibration. At this point, a re-calibration procedure can be performed. In response to completing the re-calibration procedure, the method includes the step of transitioning the OMS from the maintenance mode back to the in-service mode.

Abstract: Embodiments of the present disclosure are directed toward techniques and apparatus comprising at least one layer of an ONN that includes an optical matrix multiplier provided in a semiconductor substrate to receive a plurality of optical signal inputs and to linearly transform the plurality of optical signal inputs into a plurality of optical signal outputs. The optical matrix multiplier comprises one or more 2×2 unitary optical matrices optically interconnected to implement a singular value decomposition (SVD) of a matrix, and a nonlinear optical device coupled with the optical matrix multiplier in the semiconductor substrate, to receive the optical signal outputs and to provide an optical output that is generated in a nonlinear manner in response to the optical signal outputs of the optical matrix multiplier reaching saturation or attenuation. Additional embodiments may be described and claimed.

Abstract: Systems and methods for characterizing an optical fiber performed in part by an optical node (12) in an optical line system (10) include performing one or more measurements to characterize the optical fiber (16, 18) with one or more components (50, 52) at the optical node (12), wherein the one or more components (50, 52) perform functions during operation of the optical node (12) and are reconfigured to perform the one or measurements independent of the functions; and configuring the optical node (12) for communication over the optical fiber (16, 18) based on the one or more measurements. The one or more components can include any of an Optical Service Channel (OSC), an Optical Time Domain Reflectometer (OTDR), and an optical amplifier. The configuring can include setting a launch power into the optical fiber based on the one or more measurements.

Abstract: A network system includes a first device and a second device coupled to the first device. The second device configured to calculate a bandwidth of an optical signal narrowed by a wavelength filter from the number of wavelength filters on a transmission route of the optical signal, to select, based on a plurality of combinations of a degree of multilevel and the baud rate, and a correspondence between a lower limit value of a bandwidth of the optical signal and a lower limit value of an optical signal to noise ratio (OSNR) for maintaining predetermined quality of the optical signal, one or more first combinations from the plurality of combinations, to select a second combination from the one or more first combinations, and to set the degree of multilevel and the baud rate of the second combination in the first device.

Abstract: To ensure the origination of an emergency call from a terminal device when a communication failure due to the continuous light-emission of an ONU occurs in a PON system, a PON system includes an OLT and a plurality of ONUs connected to the OLT through an optical branching device, where data is transmitted to the OLT by time-division multiplexing. The ONU includes an emergency call detection unit that detects an emergency call request from a telephone terminal, and an emergency call origination control unit that outputs, to the optical branching device, a disconnection request for disconnecting ONUs from the OLT when the emergency call request is detected and connection of the ONU to the OLT is not established. The optical branching device includes an optical line control unit that disconnects the ONUs from the OLT in response to the disconnection request.

Abstract: Methods and apparatus are provided for locating a fault in an optical communication link. In one aspect, a method comprises determining a fault in a first optical link, and determining a fault in a second optical link. The method then determines that a first portion of the first optical link is co-located with a second portion of the second optical link and identifies, as a result of determining that the first portion is co-located with the second portion, that the fault in the first optical link is located in the first portion and/or the fault in the second optical link is located in the second portion.

Abstract: A receiver optical sub-assembly, a combo bi-directional optical sub-assembly, a combo optical module, an optical line terminal, and a passive optical network system, where the receiver optical sub-assembly includes a first transistor-outline can, where a light incident hole is disposed on the first transistor-outline can, and where a first demultiplexer, a first optical receiver, a second optical receiver, and an optical lens combination are packaged in the first transistor-outline can.

Abstract: An intelligent subsystem coupled with one or more radio transceivers, a voice processing module/a first set of computer implementable instructions (stored in a non-transitory storage media) to understand a voice command in a natural language and a second set of computer implementable instructions (stored in the non-transitory storage media) to provide learning or intelligence to the intelligent subsystem in response to a user's interest/preference, is disclosed. Furthermore, the intelligent subsystem is sensor-aware or context-aware.

Abstract: A power over fiber system includes: a power sourcing equipment, a powered device, an optical fiber cable, a temperature sensor and a controller. The power sourcing equipment includes a semiconductor laser that oscillates with electric power, thereby outputting feed light. The powered device includes a photoelectric conversion element that converts the feed light from the power sourcing equipment into electric power. The optical fiber cable transmits the feed light from the power sourcing equipment to the powered device. The temperature sensor detects a temperature of the photoelectric conversion element. The controller performs a process of lowering an output level of the feed light in response to the temperature detected by the temperature sensor being equal to or higher than a predetermined threshold value, and performs a process of raising the output level of the feed light in response to the temperature being lower than the predetermined threshold value.

Abstract: A waveguide array that includes a plurality of waveguides disposed in a substrate. The plurality of waveguides include one or more first waveguides that have a first propagation constant and one or more second waveguides that have a second propagation constant, where the first propagation constant differs from the second propagation constant. The one or more first waveguides and the one or more second waveguides are disposed in the substrate in a linear distribution and at least a portion of the linear distribution is arranged based on a quasi-periodic sequence having a plurality of sequence segments. Each sequence segment is determined based on a quasi-periodic function, has an order, and corresponds to an arrangement segment of a first waveguide, a second waveguide, or combinations thereof. The linear distribution includes at least one arrangement segment corresponding with a third-order sequence segment or higher of the quasi-periodic sequence.

Abstract: An optical communication system includes an optical transmitter and one or more processors. The optical transmitter is configured to output an optical signal, and includes an average-power-limited optical amplifier, such as an erbium-doped fiber amplifier (EDFA). The one or more processors are configured to receive optical signal data related to a received power for a communication link from a remote communication system and determine that the optical signal data is likely to fall below a minimum received power within a time interval. In response to the determination, the one or more processors are configured to determine a duty cycle of the optical transmitter based on a minimum on-cycle length and a predicted EDFA output power and operate the optical transmitter using the determined duty cycle to transmit an on-cycle power that is no less than the minimum required receiver power for error-free operation of the communication link.

Abstract: Methods, devices, and systems are described for free space optical communication. An example method can comprise generating a first linearly polarized optical signal having a wavelength and a first type of linear polarization and converting the first linearly polarized optical signal to a first circularly polarized optical signal. The first circularly polarized optical signal can be output into free space. The method can comprise converting a second circularly polarized signal, received via free space using the wavelength, to a second linearly polarized optical signal. The second linearly polarized optical signal can have a second type of linear polarization different than the first type. The method can comprise directing, via a polarizing beam splitter, the second linearly polarized optical signal to one or more detectors configured to output data.

Abstract: An adaptive equalizer includes a sample buffer that temporarily stores data obtained by fractional sampling at a sampling rate that is larger than one time and smaller than two times a symbol rate; and a processor coupled to the sample buffer and configured to: specify position of a training sequence in the data based on a correlation value between a first set of (f×T) samples and a second set of (f×T) samples following the first set of samples, assuming that the sampling rate is f, and a symbol length of a code pattern included in the training sequence inserted in the data is T, and calculate an initial value of a tap coefficient set to a tap of an adaptive equalization filter based on the specified training sequence, wherein the symbol length is set to be changeable so that f×T is an integer.

Abstract: Devices, methods for analog-to-digital converters (ADCs) that perform high-dynamic range measurements based on optical techniques are disclosed. In one example aspect, an optical encoder includes a polarization rotator configured to receive a train of optical pulses, and an electro-optic (EO) modulator coupled to an output of the polarization rotator. The EO modulator is configured to receive a radio frequency (RF) signal and to produce a phase modulated signal in accordance with the RF signal. The optical encoder also includes a polarizing beam splitter coupled to the output of the EO modulator; and an optical hybrid configured to receive two optical signals from the polarizing beam splitter and to produce four optical outputs that are each phase shifted with respect to one another.

Abstract: A transmitting apparatus includes: a first processor circuit; a second processor circuit; a modulation circuit; and a switch circuit, wherein the first processor circuit is configured to execute a generating process that includes mapping each of a plurality of bit strings to a symbol in predetermined order for each number of bits according to a multivalued degree of a multilevel modulation method, and generating a symbol information piece according to the symbol, wherein the modulation circuit is configured to modulate light in accordance with the symbol information piece based on the multilevel modulation method; wherein the second processor circuit is configured to execute a detecting process that includes detecting each of inputs of a plurality of data signals, wherein the switch circuit is configured to select the plurality of bit strings based on a detection result of inputs of the plurality of data signals.

Abstract: An architecture for surveillance of hybrid fiber coaxial (HFC) 5th generation (5G) Long Term Evolution (LTE) small cell devices using mobile edge computing techniques hosted by a HFC device is disclosed. A method can comprise receiving first data representing a quality of service value associated with a small cell device of a first group of 5G small cell devices; retrieving second data representing a historical quality of service value associated with a second group of 5G small cell devices; as a function of the first data and the second data, generating a change value for the small cell device; and based on the change value, facilitating an adjustment in an operation of the small cell device.

Abstract: A receiving and sending integrated chip for an OLT, which relates to the field of integrated circuits and optical communications. The present invention arms at resolving the problem of high production costs and long production cycle due to the fact that the functions of a limiting amplifier and a laser driver of a traditional OLT end optical module based on a GPON and an EPON are implemented by means of two circuit chips. The present invention provides two solutions. The first solution is designed based on the EPON, a transmitter threshold value configuration mode is that the threshold value configuration is implemented after an upper computer and a slave I2C circuit in the chip cooperate to complete electrifying, and LOS signal determination in a receiver can be automatically reset by means of a chip internal module.