Abstract: A wavelength de-multiplexing system that receives a wavelength multiplexed signal and generates electrical signals corresponding to the optical signals is disclosed. The optical receiver module includes a lens, a lens unit, and an optical de-multiplexer (O-DeMux). The lens converts the wavelength multiplexed signal into a quasi-collimated beam. The lens unit narrows a diameter of the quasi-collimated beam. The O-DeMux de-multiplexes the narrowed quasi-collimated beam coming from the lens unit by wavelength selective filters (WSFs) each having optical distances from the lens unit different from each other.

Abstract: An optical receiver that demodulates an optical modulation signal into a baseband signal, which is an electrical signal, and decodes a received symbol acquired by converting the baseband signal. The optical receiver includes: an analog-to-digital converter that converts the baseband signal into a digital signal of which the number of samples per received symbol is M/N (samples/symbol), M and N being positive integers, M/N being not an integer, and “M>N” being satisfied; and an adaptive equalization processing unit that executes an equalization operation set in advance to output the received symbol on the basis of the digital signal of which the number of samples per received symbol is M/N (samples/symbol) and a predetermined tap coefficient digital signal equalization tap coefficients used for equalization of a signal, the coefficient being updated in any sampling period.

Abstract: The invention relates to optical communication methods and systems. In particular, the invention relates to an optical communication method and system which is configured to create a multiplexed beam from an incident beam, wherein the multiplexed beam comprises a predetermined number of spatial modes simultaneously generated and multiplexed together in a fashion that is independent of wavelength. The spatial modes have two degrees of spatial freedom. The multiplexed beam is de-multiplexed downstream from multiplexing thereof in the communication system in a simultaneous fashion independent of wavelength to yield the predetermined number of spatial mode. The modes are used in optical communication as channels or as bits in a bit (de) encoding scheme.

Abstract: Provided is an Active Optical Cable (AOC) device for short-range optical communication. The AOC device includes an electrical wire between a transmitter and a receiver for the feedback of a monitoring signal from the receiver. The receiver further includes a monitoring circuit to control the compensation of a high frequency component of an equalizing filter, acquire the result of receiving signal size determination and a high frequency component compensation from the equalizing filter, and perform the feedback of the acquired monitoring signal to the transmitter through the electrical wire. The transmitter further includes a transmitter control circuit to receive the feedback monitoring signal from the receiver through the electrical wire and control a high frequency component control code of the high frequency component control circuit and an optical signal output size control code of the optical device driving circuit based on the received monitoring signal.

Abstract: The application discloses an optical network planning method for asymmetric traffic transmission over a multi-core fiber optical network and a network using the same. The method comprises: acquiring an asymmetric traffic demand over a multi-core fiber optical network to obtain a target service; establishing a corresponding route depending on the target service, and selecting cores in a multi-core fiber and allocating corresponding frequency slots in an interleaving and counter-propagating manner to each link along the route to optimize optical network planning and design. With the method provided by the application, through selecting cores in a multi-core fiber and allocating corresponding frequency slots in an interleaving and counter-propagating manner to each link along the route, the inter-core crosstalk is suppressed and network capacity efficiency is increased, thereby optimizing optical network planning and design for traffic transmission over the multi-core fiber optical network.

Abstract: In particular embodiments, a system may include a spacecraft and optical ground terminals. The spacecraft includes at least an optical space terminal and a space switch unit. The space switch unit is configured to receive physical layer data frames from one optical space terminal, regenerate data-link layer data packets based on the physical layer data frames and route the regenerated data-link layer data packets to another optical space terminal. The optical ground terminals are configured to receive data-link layer data packets by one of the optical ground terminals, encode the received data-link layer data packets into physical layer data frames, transmit encoded physical layer data frames from one of the optical ground terminals to a respective optical space terminal through multiple forward channels at a data rate of 1 Tbps or above, the encoded physical layer data frames are decoded by the respective optical space terminal.

Abstract: A system and method for extending the path length of an electromagnetic wave signal traveling between apertures is disclosed.

Abstract: A distributed radio access network (RAN) is provided. A selected wireless transceiver node(s) in a selected coverage cell receives a radio frequency (RF) test signal(s). The selected wireless transceiver node(s) determines an effective gain value based on a predefined characteristic of the RF test signal(s). The selected wireless transceiver node(s) communicates the effective gain value and other related parameters to a server apparatus in the distributed RAN. The server apparatus determines a common gain value for the selected wireless transceiver node(s) in the selected coverage cell based on the parameters. Accordingly, the selected wireless transceiver node(s) operates based on the common gain value.

Abstract: A Sagnac loop coherent phase modulated RF photonic link employing an ACP-OPLL linear phase demodulator was presented. This structure demonstrated stable signal transmission over a 1-km long coherent RF photonic link.

Abstract: A photonic radio-frequency receiver with mirror frequency suppression function, in which a single modulator is utilized to form a photoelectric oscillator so as to generate high-quality and low-phase-noise optically generated local oscillators, without the need for an external local oscillator source, and at the same time, another radio-frequency port is used as a radio-frequency signal input port, thereby allowing a compact structure. By properly setting a bias point for the two-electrode modulator and orthogonally synthesizing two branches of intermediate frequency signals respectively generated by the upper and lower sideband beat frequencies of the modulated optical signal, the photonic radio-frequency receiver realizes the functions of receiving radio-frequency signals and suppressing mirror frequency signals. The present disclosure can realize a photonic mirror-frequency suppression receiver.

Abstract: A space-division multiplexed optical fiber includes a relatively high refractive index optical core region surrounded by alternating regions of relatively low and relative high refractive index material, forming concentric high index rings around the core. The optical core region supports propagation of light along at least a first radial mode associated with the optical core region and a high index ring region supports propagation of light along at least a second radial mode associated with the high index ring region. The second radial mode is different from the first radial mode.

Abstract: A phase noise compensation apparatus is used for a demodulation apparatus for demodulating a transmission signal modulated by a modulation scheme that uses phase information for data identification. A phase detector detects a phase error of a reception pilot symbol sequence included in a reception symbol sequence. A first filter refers to the phase error detected in a time series manner and sequentially estimates first phase noise components. A second filter refers to the phase error detected in a reverse time series manner and sequentially estimates second phase noise components. The synthesis processing unit estimates a phase noise component of a reception symbol based on an estimated value of the first phase noise component, an estimated value of the second phase noise component, and the phase error. The phase rotator rotates a phase of the reception symbol based on the estimated phase noise component of the reception symbol.

Abstract: Broadband subscriber switchover may be provided. First, a first gateway device may receive a first failure message from a first ring device. The first gateway device may be designated as an access fault detection agent among a plurality of gateway devices. Next, the first gateway device may receive a second failure message from a second ring device. The second failure message may be received via a second gateway device. The first ring device and the second ring device may be in an open-ring. Then the first gateway device may determine that the first ring device has been cut off from the second gateway device based upon the first failure message and the second failure message. The second gateway device may be a master device for the first ring device. The master device for the first ring device may then be switched from the second gateway device to the first gateway device.

Abstract: The invention relates a device (10) for data and/or signal transmission between two adjacent units of a multi-membered, track-guided vehicle combination, wherein the device (10) comprises at least one emitter (11) for emitting electromagnetic radiation as needed. According to the invention, the at least one emitter (11) is integrated into a lamp module (1) which is designed to be installed in a front region of a vehicle (A, B) of the multi-membered vehicle combination.

Abstract: An encoding device includes an encoding unit, DA converters, light sources, intensity modulators, and wavelength multiplexers. The encoding unit adds (NM/2) to an encoded signal having a negative minimum value in a range of the encoded signal among encoded signals of N channels of (NM+1) values obtained by calculating an inner product of a Hadamard matrix of N rows and N columns and a matrix having elements of N intensity signals of (M+1) values. The DA converters of the channels convert the encoded signals of the channels from digital signals into electrical analog signals. The light sources output light of wavelengths for use in the channels. The light intensity modulators of the channels intensity-modulate the light output from the light sources with the encoded signals converted into the electrical analog signals by the DA converters. The wavelength multiplexer outputs a wavelength-multiplexed signal obtained by wavelength-multiplexing the light intensity-modulated by the light intensity modulators.

Abstract: An optical interconnect computing module having free space optical interconnects that form communication links with other systems with like optical interconnects and with computer blades contained within the computing module. The computing module adapts to changes in the position and orientation and other factors of the optical interconnects. The optical interconnects utilize solid-state electronic and optoelectronic components and optical components. The ability to adapt is controlled by an algorithm implemented in software, firmware and logic circuits. Computing modules within an equipment rack and between equipment racks as well as blades contained within a computing module may experience changes in position and orientation due to installation misalignment, servicing of equipment, vibrations, floor sagging, thermal expansion and contraction, earthquakes, line-of-sight obstructions, manufacturing imperfections and other sources.

Abstract: A system for transmitting data over an optical communication path is configured to receive data to be encoded in a bitstream for transmission using an optical communication path and encodes the received data to obtain a bitstream. The system is further configured to determine that the bitstream includes a sequence of consecutive bits, and obtain a power level at which to transmit a portion of the bitstream based on a count of the consecutive bits in the sequence. The system may be configured to selectively activate a light source at a power level according to a modulation scheme to optically transmit the portion of the bitstream at the power level.

Abstract: Provided is a device, which is a transmission device that can improve performance, that includes: a light source; and a transmitter that generates a modulated signal based on an input signal and transmits the modulated signal from the light source as visible light by changing a luminance of the light source in accordance with the modulated signal. The transmitter includes, in the modulated signal, a plurality of items of information related to service set identifiers (SSIDs) of a plurality of mutually different access points in a wireless local area network (LAN), and transmits the modulated signal from the light source.

Abstract: A metasurface optical pulse shaper includes a metasurface with superpixels disposed on an entry side of the metasurface and a wire grid polarizer disposed on an exit surface of the metasurface for controlling a phase, amplitude, or polarization of an optical pulse, wherein the metasurface in combination with dispersers provide for optical shaping of the optical pulse. A process for optically changing a pulse shape includes dispersing a primary optical pulse; separating spatially, by frequency, primary frequency waves; changing, by superpixels, a relative phase of the primary frequency waves and producing phase waves that are separated spatially by frequency and phase; and producing a plurality of shaped frequency waves such that, from an individual phase wave, a shaped frequency wave is produced that separated spatially by frequency and phase, such that a superposition of shaped frequency waves produce a shaped optical pulse that has pulse shape that is different than the primary optical pulse.

Abstract: A method and a device are provided for monitoring OSNR system margin in optical networks which relies on the relationship that exists between the OSNR value and the ESNR value.