Abstract: A redundancy system for data transport in a Distributed Antenna System (DAS) includes a plurality of Digital Access Units (DAUs). Each of the plurality of DAUs is fed by a plurality of data streams and is operable to transport digital signals between others of the plurality of DAUs. The redundancy system also includes a plurality of Digital Distribution Units (DDUs). Each of the plurality of DDUs is in communication with each of the plurality of DAUs using cross connection communication paths. The redundancy system further includes a plurality of Digital Remote Units (DRUs). Each of the plurality of DRUs is in communication with each of the plurality of DDUs using cross connection communications paths.

Abstract: Information encoded in an uplink beam (Lu) is transmitted from transceiver (10) on earth (1) to a communication satellite (20) in orbit. The uplink beam (Lu) travels through an atmosphere (2) there between, wherein a wavefront (Wu) of the uplink beam (Lu) is distorted as a result of its propagation through the atmosphere (2). The transceiver (10) comprises a wavefront sensor (12) to measure a reference distortion (Wr?) of a wavefront (Wr) of a reference beam (Lr). Adaptive optics (11) are used to pre-correct a wavefront (Wu) of the uplink beam (Lu) prior to its transmission based on the measured reference distortion (Wr?). The reference beam (Lr) originates from a guidestar satellite (30) formed by a separate man-made object at a distance (D) from the communication satellite (20) such that the reference beam (Lr) travels through the same part (2a) of the atmosphere (2) as the uplink beam (Lu).

Abstract: Provided are an infrared protocol-based infrared code transmission circuit, a chip, a remote control device and an air conditioner. The infrared code transmission circuit includes: a carrier duration control module; a processing module that is configured to configure the carrier duration control module according to a stage type of an infrared code to be transmitted in an infrared protocol, so that the carrier duration control module generates an enabling signal; a carrier generation module that is provided to generate a PWM-type carrier signal according to the stage type of the infrared code to be transmitted in the infrared protocol, and carry out a logic operation on the PWM-type carrier signal and the enabling signal to generate and transmit the infrared code to be transmitted.

Abstract: An electro-optical apparatus having an ASIC electrically linked, by way of a multistage SerDes, to an array of optical data transmitters and receivers. In an example embodiment, a first SerDes stage is connected to the ASIC by a plurality of relatively wide, short electrical buses and further connected to a second SerDes stage by a plurality of narrower, longer electrical buses. The second SerDes stage is located in close proximity to the transmitter/receiver array to enable the signals transmitted therebetween to be switched at a high frequency rate, e.g., higher than 500 MHz. The width and length of said narrower, longer electrical buses are selected such as to support a high overall data throughput for the corresponding electrical data links between the ASIC and the transmitter/receiver array while being able to afford acceptable levels of signal integrity, power usage, and timing skews in these links.

Abstract: A process to enhance the performance of plastic optical fiber to operate with a high data rate (e.g., at least 1 gigabit per second) at high temperature (e.g., 100 degrees Celsius) for airplane avionic systems. Gigabit plastic optical fiber has a core including a dopant that enables data transmission at gigabit rates. The enhancement process uses rapid thermal cooling of the gigabit plastic optical fiber to stabilize the polymer matrix of the fiber. This rapid cooling treatment blocks dopant diffusion in a high-temperature environment, thereby avoiding degradation of the fiber's bandwidth and optical loss characteristic. Such degradation typically occurs in gigabit plastic optical fiber having core and cladding made of transparent carbon-hydrogen bond-free perfluorinated polymer.

Abstract: A test controller of a transmitting-side optical wavelength multiplexing transmission apparatus of the present invention includes a wavelength tunable filter controller configured to control a center wavelength and a wavelength band of an optical signal that a wavelength tunable filter transmits; and a test transponder controller configured to control a wavelength band of a test optical signal generated by a test transponder and a wavelength interval between the test optical signal and the optical signal that the wavelength tunable filter transmits. A test controller of a receiving-side optical wavelength multiplexing transmission apparatus of the present invention includes a wavelength tunable filter controller configured to control a center wavelength and a wavelength band of an optical signal that a wavelength tunable filter transmits; and a test transponder controller configured to control a center wavelength and a wavelength band of a test optical signal received by a test transponder.

Abstract: A physical voxel, a volumetric testbed, and method for physically simulating a photonic device are described herein. The volumetric testbed comprises a simulation stage and a controller. The simulation stage includes a three-dimensional array of physical voxels configurable to represent the photonic device operating in response to electromagnetic radiation. The physical voxels includes a field detector to measure a local field response and an impedance adjuster to adjust an impedance to the electromagnetic radiation. The controller is coupled to memory, which stores instructions that when executed by one or more processors included in the controller causes the volumetric testbed to perform operations including determining a global field response of the photonic device and adjusting the impedance of the physical voxels to refine a design of the photonic device.

Abstract: A free space optical communication system transmits and receives optical signals in a colorless manner using an optical circulator. The system installs the optical circulator with a single mode (SM) fiber at port 1, a double clad (DC) fiber at port 2, and a multimode (MM) fiber at port 3. The system injects a first optical signal into a core of the SM fiber. The system then routes the first optical signal at port 1, using the optical circulator, into a SM core of the DC fiber via Port 2. Further, the system injects a second optical signal into a first cladding of the DC fiber. The system then routes the second optical signal at port 2, using the optical circulator, into the MM fiber via Port 3.

Abstract: There is provided apparatuses to detect occurrence and location of damages on optical fiber links in advance by converting an optical span in optical network to an interferometry based sensing media. The interferometry based sensing media may enable detection of mechanical perturbation or mechanical vibration occurred on optical fiber links across optical network. The system employed with the interferometry based sensing media can detect occurrence of mechanical perturbation or mechanical vibration as well as discover the location of such event occurred using standard interferometry based sensing techniques.

Abstract: Implementations described and claimed herein provide systems and methods for an optical domain controller for managing and maintaining a record of network component configuration and interconnections. The optical domain controller detects changes in a configuration of optical network elements in response to a requested service from the network, coordinates additional changes in configurations to optical network elements that may be affected by the detected change, communicates with the optical network elements to incorporate the changes to the configurations of the network element, and stores the configurations and states of the network elements. The use of the optical domain controller may thus replace or supplement a database storing network configuration information by automatically managing changes to the network as new services are instantiated directly on the optical network elements.

Abstract: Some embodiments of the disclosure relate to an optical transmission system that operates at a wavelength in the range from 950 nm to 1600 nm and that employs a single-mode optical transmitter and an optical receiver optically coupled to respective ends of a multimode fiber designed for 850 nm multimode operation. The optical transmission system also employs at least one single mode fiber situated within the optical pathway between the optical transmitter and the receiver and coupled to the multimode fiber.

Abstract: Example embodiments disclose a tunable optical pair source (TOPS) configured to generate first and second output optical beams having respective first and second frequencies that are phase locked with each other. The TOPS may include a first laser, such as a tunable laser, configured to generate a first laser beam, a radio frequency (RF) oscillator configured to transmit an RF reference signal, a beam splitter in optical communication with the first laser, and an electro-optic modulator configured to modulate the second split beam with the RF reference signal to form a modulated beam having a first sideband comb comprising a plurality of harmonics. Additionally, the TOPS may include an optical filter configured to receive the modulated beam and output a filtered optical beam, and a second laser configured to generate a second laser beam at the second frequency, the second laser being configured to receive the filtered optical beam as a seed.

Abstract: The present disclosure provides a method and a device for controlling a downlink optical signal in a passive optical network, and a computer-readable storage medium. The method includes: monitoring power of a downlink optical signal in a process of receiving the downlink optical signal; and adjusting an attenuation value of a variable optical attenuator at an ONU side according to the power of the downlink optical signal until the power of the downlink optical signal falls within a preset power range. The variable optical attenuator at the ONU side is located between an optical splitter and an ONU.

Abstract: A phase modulation device is provided that comprises a retardation device and a control device. The retardation device is characterized by first and second polarization eigenstates SOPf and SOPs. Light polarized according to the second polarization eigenstate SOPs acquires, upon passing through said retardation device, a delay with regard to light polarized according to the first polarization eigenstate SOPf, which delay corresponds to ?/2±30%, preferably ?/2±20% and most preferably ?/2±10%. The retardation device is arranged to receive input light having a polarization state SOPf; that defines an angle with respect to one of the first and second polarization eigenstates SOPf, SOPs within a predetermined angle range and to emit output light. The control device is configured to control at least one of a change of the angle between the polarization state SOPi; of the input light and the respective polarization eigenstate SOPf, SOPs by less than 0.1*?, preferably less than 0.05*? and most preferably less than 0.

Abstract: Exemplary embodiments include a dual-mode optical device having an optical reflector, an optical transmitter, and a detector. The optical reflector is configured to reflect an incident first optical signal having a first wavelength, wherein the first optical signal includes a plurality of intermittent active and inactive durations. The optical transmitter is configured to emit a second optical signal having a second wavelength substantially similar to the first wavelength. The detector is configured to: determine the active and inactive durations of the first optical signal; and inhibit the optical transmitter from emitting the second optical signal during the detected active durations of the first optical signal.

Abstract: A method and an apparatus for predicting a fault of an optical circuit includes determining a classification threshold of an operating parameter based on a classification sample set corresponding to the operating parameter of optical circuit and predicting, based on comparison results between the classification threshold and a plurality of measured values in a sequence, whether a fault occurs in the future on the optical circuit corresponding to the sequence.

Abstract: A communication device is provided that estimates one or more disturbance values associated with one or more components of the communication device, and adjusts the communication device to change a received power of the output signal. The communication device includes a transmitter having a seed laser configured to provide an amount of bandwidth for an output signal, an Erbium-doped fiber amplifier (EDFA) configured to increase an amplitude of the output signal, and a single mode variable optical attenuator (SMVOA) configured to decrease the amplitude of the output signal.

Abstract: An apparatus in one embodiment includes a transceiver housing operable to be inserted into a port of a host system, the port comprising at least a first channel and a second channel. The transceiver housing may be a compact small form-factor (SFP) pluggable module housing. The apparatus also includes a printed circuit board mounted in the transceiver housing and an electrical interface of the printed circuit board operable to interface with the port of the host system. The electrical interface includes a first transmit pin and a first receive pin configured to interface with the first channel of the port and a second transmit pin and a second receive pin configured to interface with the second channel of the port. A first connector couples the first transmit pin and the second receive pin, and a second connector couples the second transmit pin and the first receive pin.

Abstract: An optical receiver is provided with: an optical reception circuit which receives wavelength multiplexed light including signal light, converts the signal light into an electrical signal by coherent detection of the signal light using local oscillation light, and outputs the power of the local oscillation light, the bit error rate of the signal light and the electrical signal; and a controller which monitors the power of the local oscillation light and the bit error rate, calculates the signal-to-noise ratio of the signal light on the basis of the power of the local oscillation light and the bit error rate, and finds the number of wavelengths of the wavelength multiplexed light and the power per wavelength of the signal light on the basis of the signal-to-noise ratio and the power of the local oscillation light.

Abstract: Methods and systems for CWDM MUX/DEMUX designs for silicon photonics interposers are disclosed and may include an optical transceiver including a silicon photonics interposer, a polarization splitter, a lens array, and a prism with a coarse wavelength division multiplexing (CWDM) coating and a high reflectivity (HR) coating. The polarization splitter, lens array, and prism are coupled to the silicon photonics interposer. An input optical signal of a plurality of different wavelengths and polarizations may be received. Signals of different polarization may be spatially separated using the polarization splitter and signals of a first wavelength range may be reflected into the lens array using the CWDM coating while signals in a second wavelength range may be passed through. Signals of the second wavelength range may be reflected to the lens array using the HR coating, and optical signals may be coupled into the silicon photonics interposer using the lens array.