Abstract: Information from optical modules can be combined with information from network switches to help detect and pinpoint problems along a network communications path. A control path between a network switch and a microcontroller of an optical module can be used to obtain monitoring and debugging data from a digital signal processor (DSP) of the optical module. The DSP data can be used with performance data from the network switch to separately determine the health of the electrical and optical sections of the communications link. The ability to pinpoint problems with the communications link enables appropriate remedial actions to be determined and taken automatically.

Abstract: This disclosure describes systems, methods, and devices related to frequency offset tracking in optical signals. A device may identify modulated light received from a light source, wherein the modulated light is received at a frame rate, and wherein the modulated light is associated with pixel clusters. The device may determine light samples based on the pixel clusters, the light samples including a first light sample and a second light sample. The device may determine a vector norm between the first light sample and the second light sample using an oversampling factor. The device may determine that the vector norm is below a threshold. The device may determine a start frame delimiter (SFD) based on the vector norm. The device may demodulate the symbol based on the oversampling factor.

Abstract: A system for loading a fiber optic transport system includes a wavelength selective switch (WSS) having inputs and an output connected to an optical fiber, wherein the inputs are connected to one or more lines having data-bearing channels thereon; and an amplified spontaneous emission (ASE) generator connected to one of the inputs of the WSS, wherein the WSS is configured to perform a channel addition through substitution of an ASE channel from the ASE generator for a data-bearing channel, and a channel deletion through substitution of a data-bearing channel for an ASE channel from the ASE generator, and wherein, to limit perturbations on the optical fiber due to channel additions and deletions, the WSS is configured to limit a number of channels that are switched at a same time for a set of channel additions or deletions.

Abstract: The invention relates to a method of determining a time-of-flight of an optical signal between a starting point and a reflection point of an optical path, comprising: supplying to the path at least one optical probing signal; detecting an electrical return signal according to an optical return signal returning from the path in response to a corresponding one of the probing signals using direct detection; deriving at least one receive code sequence by sampling and slicing the return signal using a sampling rate corresponding to a bit rate of a sequence of pulses of the probing signal; determining a correlation function by correlating the transmit code sequence and the at least one receive code sequence; and identifying a main peak of the correlation function that corresponds to the reflection point and a time position of the peak, and determining the time-of-flight as the time position of the peak.

Abstract: An optical transmitter includes: a bit converter that processes input bits in units of four bits, and generates an output bit sequence having eight bits based on one of a first conversion table, a second conversion table, and a third conversion table; and a symbol mapper that allocates the output bit sequence to an X-polarization and to a Y-polarization of each of two consecutive time slots. The bit converter performs a process of generating the output bit sequence based on the first conversion table, the second conversion table, and the third conversion table. The bit converter performs the process such that a sequence of two most significant bits and a sequence of two least significant bits of the output bit sequence are respectively associated with values that are allocated respectively to two constellation points having phases different by 180 degrees on a complex plane.

Abstract: The present invention relates to an optical network element (30, 34) comprising a wavelength selective switch, WSS, (432, 136) with one or more input ports, a working output port (38) and a separate protecting output port (40), the WSS (432) being configurable to a working configuration, in which one or more channels are routed from said one or more input ports to the working output port (38), and being configurable to a protecting configuration, in which said one or more channels or a subset thereof are routed from said one or more input ports to the protecting output port (40), or with a working input port (42) and a protecting input port (44) and with one or more output ports, the WSS (136) being configurable to a working configuration, in which one or more channels are routed from the working input (42) port to the one or more output ports, and being configurable to a protecting configuration, in which one or more channels are routed from the protecting input port (44) to the one or more output ports, a c

Abstract: A compensating device includes at least one detector configured to detect intensity variation of the optical signal, at least one filter configured to extract a band where most of the optical phase distortion is generated from a component of the intensity variation of the optical signal, a control circuit configured to generate, based on the extraction with the at least one filter, a compensation signal exhibiting temporal intensity variation of the input optical signal, at least one compensation signal light source configured to output, based on the compensation signal of a controller, a compensation signal light exhibiting intensity variation in opposite phase to the temporal intensity variation of the input optical signal and having a different wavelength from a wavelength of the optical signal and an optical multiplexer configured to output to a transmission path a signal light formed by combining the optical signal and the compensation signal light.

Abstract: An optical space communication device includes first and second optical antennas that transmit first and second transmission light and receive first and second reception light, first and second delay circuits that provide a delay to transmission data included in the first and second transmission light, third and fourth delay circuits that provide a delay to reception data included in the first and second reception light, and a receiver that sets a delay of at least one of the first delay circuit and the second delay circuit and sets a delay of at least one of the third delay circuit and the fourth delay circuit, based on delays between the first and third delay circuits and the first optical antenna, delays between the second and fourth delay circuits and a fourth optical antenna, and delays between a communication destination and the third and fourth delay circuits.

Abstract: A wavelength division multiplexing (WDM)-based photonic radar architecture is disclosed. The WDM-based photonic radar incorporates a WDM photonic input of N component wavelengths modulated by an IF-LFM input signal and its 90-degree phased counterpart. The modulated WDM photonic signal is split one branch sent to a photodetector for generation of an RF outbound signal and transmission of the signal, which is reflected by a target and received as an RF echo signal after a time delay. The other branch has each component wavelength time-adjusted by a second time delay for each wavelength. The resulting time-delayed WDM photonic signal is modulated again based on the received RF echo signal and split into wavelength selective channels. Filters in each channel extract two adjacent photonic signals converted to RF output signals by photodetectors. RF filters select a single RF signal for processing based on the closest difference between the two time delays.

Abstract: The invention relates to an optical receiver for receiving visible light, wherein the visible light comprises an intensity modulated signal. The optical receiver comprises an optical intensity modulation filter configured for filtering the intensity modulated signal from the visible light and a photo detector configured for detecting said filtered modulated signal. The invention also relates to an—illumination system comprising such a optical receiver. The optical filter preferably comprises a fluorescent layer.

Abstract: Techniques for data transmission including receiving, at a geostationary earth orbiting satellite, forward-direction user data via a forward optical link; transmitting, by the geostationary earth orbiting satellite via multiple radio frequency (RF) spot beams, the forward-direction user data received via the forward optical link; receiving, at a stratospheric high-altitude communication device, forward-direction user data via multiple concurrent forward RF feeder links; transmitting, by the stratospheric high-altitude communication device via the forward optical link, the forward-direction user data received via the forward RF feeder links; transmitting, by each of multiple ground-based feeder RF terminals at a same RF feeder site, a respective one of the forward RF feeder links. At least 95% of forward feeder data throughput for all of the forward RF service link transmissions by the satellite is carried via the forward optical link and the forward RF feeder links.

Abstract: Systems and methods for performing connectivity verification testing and topology discovery in a reconfigurable optical add/drop multiplexer (ROADM) are provided. The ROADM can include a ROADM block having a plurality of internal ports connected to a fiber shuffle via respective optical fibers. The ROADM block includes a test signal transmitter configured to inject an outgoing test signal having a unique signature into each internal port. The outgoing test signals are out-of-band of optical data signals traversing the ROADM. The ROADM block includes a test signal monitor configured to monitor for incoming test signals at each of the internal ports. The test signal monitor is configured to validate, based on a signature of an incoming test signal received at an internal port of the ROADM block, whether a valid connection exists between the internal port and an internal port of a second ROADM block.

Abstract: A fiber optic system is provided including a first and second fiber optic assembly, each comprising a body defining a fiber routing volume and a plurality of fiber optic components disposed on the body. The first fiber optic assembly includes a first plurality of optical filters disposed within the first fiber routing volume. The first plurality of optical filters define a first plurality of dense wavelength division multiplexing (DWDM) channels, test channels, an express port, and an upgrade port. A second plurality of optical filters disposed within the second fiber routing volume. The second plurality of optical filters define a second group comprising a second plurality of DWDM channels. The test channels and the express port of the first fiber optic assembly are utilized for both the first fiber optic assembly and the second fiber optic assembly.

Abstract: A polarization-independent optical switching system capable of rerouting light signals is disclosed. The system includes a plurality of switching cells, each including a pair of bus waveguides that are formed in different planes above a substrate. Each bus waveguide supports low-loss propagation of both the TE- and TM-polarization modes and are optically decoupled when the switch is in an unswitched state. In its switched state, a shunt waveguide that also supports low-loss propagation of both polarization modes is moved into proximity with both bus waveguides to form a pair of adiabatic directional couplers that enable the light signal to evanescently couple between each bus waveguide and the shunt waveguide. As a result, the path of a light signal through the switching cell is reconfigured.

Abstract: An integrated photonics monopulse comparator includes an array of squinted monopulse elements, each monopulse element producing an RF signal in response to a received inbound signal and each RF signal having a squinted RF voltage. The comparator includes a laser source for producing a wavelength division multiplexed (WDM) optical signal comprising multiple components having discrete wavelengths. The component signals may be multiplexed and demultiplexed and routed through cascading optical phase modulators, each phase modulator connected to a monopulse element and capable of modulating a component signal according to the voltages of the RF signals produced by the corresponding monopulse element. The resulting modulated component optical signals undergo coherent photodetection by arrays of paired photodiodes, each pair receiving component signals of like wavelength.

Abstract: An optical transceiver includes a housing and an optical transceiving module. The housing includes a main body and a heat conductive component. The heat conductive component is disposed on the main body, and a thermal conductivity of the heat conductive component is larger than a thermal conductivity of the main body. The optical transceiving module is disposed in an accommodation space of the main body of the housing.

Abstract: Systems and methods for setting fiber input power for an optical transmission path may include determining an initial modulation format representing a uniform distribution QAM format, the initial modulation format associated with a first fiber input power and a first spectral efficiency, configuring optical transponders to apply probabilistic shaping to the initial modulation format when transmitting traffic over the optical transmission path, the traffic including probabilistically shaped signals with a second spectral efficiency, determining, dependent on the second spectral efficiency, a second fiber input power, and configuring optical amplifiers along the optical transmission path to transmit the traffic comprising the probabilistically shaped signals over the optical transmission path using the second fiber input power.

Abstract: A multi-beam photonic monopulse comparator is disclosed. Photonic inputs incorporating M component wavelengths are split into equivalent inputs for each quadrant subarray and array element (e.g., N array elements in each quadrant subarray). Within each array element, the component wavelengths are apodized by attenuators and the apodized input signal modulated by a received inbound RF signal (via broadband Mach-Zehnder electro-optical modulators). The resulting positive-polarity and negative-polarity modulated photonic signals are demultiplexed and each component wavelength time-delayed. Time-delayed wavelength-selective optical delay channels are copied and combined by single mode/multi-mode (SM/MM) couplers into photonic antenna beams and simultaneously generated photonic comparator outputs (elevational difference, sum, azimuthal difference) for each component wavelength.

Abstract: The disclosure provides for a method and a system for tracking an optical communication beam based on polarization modulation of the optical communication beam. The method includes polarizing, at a first communication device, an optical communication beam in a polarization pattern. The optical communication beam carries an optical signal. The polarization pattern encodes information by varying between a first polarization direction and at least one second polarization direction. The polarized optical communication beam is then transmitted from the first communication device to a second communication device. At the second communication device, the polarized optical communication beam is processed to extract the encoded information, and the encoded information is used at the second communication device to track the optical communication beam.

Abstract: A system for determining a location of a work machine operator relative to a work machine comprises a machine controller, a radio frequency receiver, and an infrared transmitter unit. The unit comprises a plurality of infrared transmitters configured to generate infrared signals that collectively divide a 360-degree area around the infrared transmitter unit into a plurality of zones. A remote controller remote from the work machine, which comprises a radio frequency transceiver and an infrared receiver, is configured to receive the infrared signal generated by at least one of the plurality of infrared transmitters. The remote controller has a computer system which is configured to decode information within the one or more infrared signals to determine whether the operator is in an approved zone. The computer system enables the radio frequency transceiver to communicate with the radio frequency receiver upon determining that the operator is in the approved zone.