Abstract: An optical transmission system comprises at least one first connection point and one second connection point arranged to transmit and receive at least one channel signal transmitted via at least one optical means connecting the first connection point and the second connection, wherein each of the at least one channel signal is reversibly configurable to be transmitted in either a first direction or a second direction between the first connection point and the second connection point. A method of transmitting at least one channel signal between a first connection point and a second connection point via at least one optical media in an optical transmission system, wherein each of the at least one channel signal is reversibly configurable to be transmitted in either a first direction or a second direction between the first and the second connection points.

Abstract: An optical module processes first FEC (Forward Error Correction) encoded data produced by a first FEC encoder. The optical module has a second FEC encoder for further coding a subset of the first FEC encoded data to produce second FEC encoded data. The optical module also has an optical modulator for modulating, based on a combination of the second FEC encoded data and a remaining portion of the first FEC encoded data that is not further coded, an optical signal for transmission over an optical channel. The second FEC encoder is an encoder for an FEC code that has a bit-level trellis representation with a number of states in any section of the bit-level trellis representation being less than or equal to 64 states. In this manner, the second FEC encoder has relatively low complexity (e.g. relatively low transistor count) that can reduce power consumption for the optical module.

Abstract: In some embodiments, an apparatus includes a reconfigurable optical add-drop multiplexer (ROADM). The ROADM has a wavelength selective switch (WSS) that does not perform power equalization when the WSS is operative. The ROADM also has a first pre-amplifier, a first channel power equalizer operatively coupled to the first pre-amplifier, a second pre-amplifier operatively coupled to the first channel power equalizer and the WSS, a first post-amplifier operatively coupled to the WSS, a second channel power equalizer operatively coupled to the first post-amplifier, and a second post-amplifier operative coupled to the second channel power equalizer.

Abstract: According to an example aspect of the present invention, there is provided an apparatus comprising at least one memory configured to store positioning information, and at least one processing core configured to determine a position estimate for the apparatus based at least in part on the positioning information and on at least one direction of a steerable optical beam, the steerable optical beam being steerable by the apparatus.

Abstract: A system and method for automatic discovery of an optical cable route. The method comprises: a light source power meter automatically monitoring an attenuation value of an optical cable fiber core, the optical cable fiber core being configured in an optical cable route; when the power meter generates an alarm, determining a level of the optical power alarm and reporting the alarm condition of the optical cable route in real time; and a drive automatically searching for available optical cable routes to provide options of available optical cable routes for real-time allocation of services.

Abstract: A device comprising: an input for receiving a signal from a rolling-shutter camera which captures frames by exposing a lines of each frame in sequence, the signal comprising a coded light signal; and a signal processing module arranged to obtain a respective sample of the coded light signal from each of a number of said lines, being a substantially smaller number of the lines than exposed by the camera in each frame. The coded light signal comprises a message having a duration longer than this number of lines, and the message is repeated multiple times with a timing such that a different part of the message is seen by the camera in each of a plurality of different ones of said frames. The signal processing module is configured to time align the different parts of the message from the plurality of different frames, and reassemble the message from the time-aligned parts.

Abstract: A method implemented by a first network element (NE) comprises receiving, by a receiver of the first NE, a burst from a second NE, wherein the burst comprises at least one training symbol (TS), storing, by a memory of the first NE, a channel response for a link between the first NE and the second NE, wherein the first NE is communicatively coupled to the second NE, wherein the channel response is based on a current channel response estimated using at least one TS in the burst and a previously stored channel response, and wherein the previously stored channel response is based on a plurality of bursts previously received from the second NE, and compensating, by a processor coupled to the receiver and the memory of the first NE, modulated symbols in the burst using the channel response.

Abstract: A method is described in which a loss of spectrum in an optical signal having an optical signal spectrum is detected. The optical signal is transmitted from a first node to a second node. In response to detecting the loss of spectrum in the optical signal, at least one idler carrier without data imposed is supplied into the optical signal spectrum transmitted from the first node to the second node, the optical signal spectrum encompassing a frequency band including a plurality of optical channels, the idler carrier being amplified stimulated emission light having a frequency corresponding to a first optical channel of the plurality of optical channels.

Abstract: An optical communication apparatus according to an embodiment of the present invention includes: a light emitting element; a transmission driver that drives the light emitting element; a light receiving element capable of changing a multiplication factor by a bias voltage; a temperature sensor; a computing unit that calculates a drive rate of the transmission driver; and an adjusting unit that adjusts the bias voltage applied to the light receiving element. The adjusting unit adjusts the bias voltage by linear computation using a plurality of target values of the bias voltage for combinations of a plurality of temperatures and a plurality of drive rates, based on a temperature detected by the temperature sensor and a result of calculation of the drive rate.

Abstract: A low-cost, robust method for automatically tuning a coupled resonator to match a wavelength of electromagnetic radiation emitted from an applied laser source. Dithering signals are used for automatic wavelength tuning and thermal stabilization of microring resonators. The disclosed method can be applied using low-speed analog and digital circuitry, to create a complete photonic interconnection network. The methods disclosed also automatically detect, measure, and correct for resonance shift.

Abstract: An apparatus and method for monitoring an individual premise return band at the side of the home, in a pedestal TAP, or in an aerial TAP is disclosed. The apparatus may be configured to be connected one to eight homes to analyze the return band spectrum, communicate this spectrum to a server for storage and/or alarm, and/or take action when the spectrum exceeds predefined limits or based on instructions received from a server.

Abstract: An energy sensing espionage detector is disclosed. The detector is designed to alert on compromised LED lighting sources used by spies on unsuspecting corporations and individuals. The detector counters one threat vector that is emerging from newly mandated energy policies to replace conventional lighting with energy efficient LED lighting. The detector senses that information is being transmitted by the light source using pulsed or modulated energy that is not detectable by the human eye.

Abstract: A signal processing device processes an electric field information signal indicating a polarization multiplexed optical signal in which different modulation formats are used. A first optical signal transmitted in a first polarization component and a second optical signal transmitted in a second polarization component are multiplexed in the polarization multiplexed optical signal. The signal processing device includes a generator and a compensation circuit. The generator selects the first polarization component or the second polarization component based on modulation formats of the first and second optical signals, and generates a compensation value for compensating for an electric field information signal of a selected polarization component based on the electric field information signal of the selected polarization component. The compensation circuit compensates for electric field information signals of the first and second polarization components using the compensation value generated by the generator.

Abstract: An optical device having a self-repair component capable of curing a defective component(s) is disclosed. To improve reliability as well as manufacturing yield, a photonic integrated circuit (“PIC”) for as a multi-channel optical line terminal (“OLT”) contains spare lasers or standby lasers configured to replace a failed laser(s). In one aspect, PIC includes a set of fixed-wavelength lasers (“FWLs”), a tunable-wavelength auxiliary laser (“TWAL”), a photonic detector, and a tuner. FWLs, for example, generate optical wavelengths representing optical signals. TWAL generates an optical signal with a spectrum of wavelengths based on a setting generated by the tuner. The photonic detector detects a defective wavelength. The tuner adjusts output wavelength of TWAL in response to the defective wavelength. Alternatively, PIC includes a working laser array, standby laser array, and spare laser array capable of providing two layer laser defective protections.

Abstract: Disclosed are a method and apparatus for registering visible light communication devices and combining a visible light communication signal and a wireless communication signal. It is an object of the present disclosure to provide a visible light communication device registration method in which a lighting device allows collective registration of the lighting device and a terminal as the terminal transmits data to a light using wireless communication.

Abstract: Disclosed herein is a dual parallel Mach-Zehnder-modulator (DPMZM) device comprising a DPMZM 10 having first and second inner MZMs arranged parallel to each other. The first inner MZM generates an in-phase component EI of an optical signal in response to a first driving voltage VI, and the second inner MZM generates a quadrature component EQ of said optical signal in response to a second driving voltage VQ. Further disclosed is a calculation unit 52 configured for receiving an in-phase component yI and a quadrature component yQ_ of a desired base-band signal, and for calculating pre-distorted first and second driving voltages VI, VQ. The calculation of the pre-distorted first and second driving voltages VI, VQ is based on a model of said DPMZM 10 accounting for I-Q cross-talk, and using an algorithm that determines said first and second driving voltages VI, VQ each as a function of both of said in-phase and quadrature components yI, yQ of said base-band signal.

Abstract: Methods and apparatus are provided for identifying a connection between a reach extender channel termination (RE-CT) and an optical network unit (ONU). A method performed by an optical line terminal (OLT) for identifying a connection between a RE-CT and an ONU includes transmitting, by the OLT, a dynamic bandwidth allocation (DBA) grant to the ONU via a multi-channel termination reach extender (MCRE), retrieving, by the OLT from the MCRE, recorded optical signal power measurements associated with an upstream transmission by the ONU, and identifying, by the OLT, the RE-CT of the MCRE that is connected to the ONU by correlating the recorded optical signal power measurements associated with the upstream transmission by the ONU with the DBA grant.

Abstract: In some embodiments, an apparatus comprises an optical transponder which includes a processor, an electrical interface and an optical interface. The processor is operatively coupled to the electrical interface and the optical interface. The optical interface is configured to be operatively coupled to a plurality of optical links and the electrical interface is configured to be operatively coupled to a router such that the optical transponder is configured to be operatively coupled between the plurality of optical links and the router. The processor is configured to perform pre-forward error correction (FEC) bit error rate (BER) detection to identify a degradation of an optical link from the plurality of optical links. The processor is configured to make modifications to packets designated to be transmitted via the optical link in response to the degradation being identified such that the router is notified of the degradation of the optical link.

Abstract: Methods and apparatus to realize high spectral efficiency in optical signals transmitted over long distances.

Abstract: An optical trunk switch supporting an Optical Time-Domain Reflectometer (OTDR) includes a transmit switch configured to provide an input signal to one or more of a primary fiber path and a standby fiber path; a receive switch configured to provide an output signal from one of the primary fiber path and the standby fiber path; and an OTDR connection configured to provide one or more OTDR signals to monitor an inactive path of the primary fiber path and the standby fiber.