Abstract: An encoding configuration method includes an optical network unit that receives first information, where the first information indicates a change amount of forward error correction codeword information relative to first forward error correction mother code. The optical network unit determines the forward error correction codeword information based on the first information. According to technical solutions provided in this application, the change amount of the forward error correction codeword information relative to the first forward error correction mother code is indicated, to help implement flexible configuration of the forward error correction codeword information.

Abstract: An OLT (110) includes: a first transceiver (122, 123) that performs optical communication with at least one first ONU; a second transceiver (124, 126) that performs optical communication with at least one second ONU; an power supply (142); a first transceiver control unit (127, 128) that controls the first transceiver (122, 123); a second transceiver control unit (129, 130) that controls the second transceiver (124, 126); and an OLT processing unit (141) that causes the first transceiver control unit (127, 128) to turn off power to the first transceiver (122, 123) during a first period when the number of the at least one first ONU falls below a predetermined number, and causes the second transceiver control unit (129, 130) to turn off power to the second transceiver (124, 126) during a second period when the number of the at least one second ONU falls below a predetermined number.

Abstract: Network devices and associated methods are provided for synchronization in an optically switched network. The network device includes one or more ports in communication with a plurality of devices via an optical switch. The one or more ports receive a master clock signal having a first frequency from a first device of the plurality of devices. The network device includes a local clock in communication with the one or more ports and operating at a second frequency. The network device includes a synchronization manager in communication with the one or more ports and the local clock and configured to be enabled and disabled. When the synchronization manager is enabled, it receives the master clock signal via the one or more ports and transmits an instruction to the local clock to operate at the first frequency.

Abstract: The present application relates to an optical transceiver apparatus, a communication node, and a communication system. The communication system includes a first communication node, a second communication node, a first optical fiber, and a second optical fiber; wherein the first communication node includes a first optical transceiver apparatus, and the second communication node includes a second optical transceiver apparatus and a third optical transceiver apparatus; the first optical transceiver apparatus is in a bidirectional optical communication connection with the second optical transceiver apparatus through the first optical fiber, and the first optical transceiver apparatus is in a bidirectional optical communication connection with the third optical transceiver apparatus through the second optical fiber; the first optical transceiver apparatus, the second optical transceiver apparatus and the third optical transceiver apparatus are all silicon optical devices.

Abstract: An optical signal sending apparatus includes an optical modulator, a differential driver, and a phase modulator. The optical modulator includes an optical input end, a first modulation region, a connection region, a second modulation region, and an optical output end. The first modulation region includes a first modulation arm and a second modulation arm. The second modulation region includes a third modulation arm and a fourth modulation arm. Each modulation arm includes an optical waveguide and electrodes on two sides of the optical waveguide. A differential drive signal is used to drive the two modulation regions, so that photoelectric signal modulation is implemented. The modulation arms are arranged in a stacked manner, so that a size of the optical modulator can be greatly reduced, thereby facilitating miniaturization.

Abstract: An on-demand distribution of pairs of polarization-entangled frequency-correlated photons is provided. The pairs are frequency-correlated in different bands of a multiband spectrum which may include the C-Band and the L-Band. The pairs are provided to wavelength selective-switches (WSS), which may be simultaneously controlled to provide the pairs to different receivers that are respectively connected to the output ports of the WSSes. Each WSS has a plurality of frequency channels of ?f-width bins aligned to the ITU grid. A network controller receives a request for the distribution of one or more pairs to a pair of receivers and controls frequency-correlated channels in the WSSes to provide the pair(s) to the receivers.

Abstract: An angular deviation optical tracking and detector device for use in optical systems such as a FSO communication systems—among others. The angular deviation optical tracking and detector device includes position sensor elements that are configured to detect any misalignment of incoming/received light and an optical tunnel structure coupled with a detector array to determine the angular deviation. The optical tracking and detector device includes a position sensor having an optical aperture configured to allow a portion of incoming light to pass through the position sensor; a plurality of position receivers positioned adjacent to the optical aperture, the plurality of position receivers configured to sense portions of the incoming light; and an optical detector array configured to detect portions of the incoming light that passes through the position sensor aperture and optical tunnel. Angular deviation may be determined from diode array readout of illuminated individual diodes.

Abstract: A method of parallelized optical link calibration of an optical section having a plurality of spans interconnecting a transmit Optical Add/Drop Multiplexer (OADM) with a receive OADM via a plurality of line amplifiers includes partitioning the optical section into a plurality of sub-sections, each including one or more spans of the plurality of spans; utilizing equipment at the plurality of line amplifiers to isolate the plurality of sub-sections from one another; and performing measurements of spans for the parallelized optical link calibration in some or all of the plurality of sub-sections at a same time. Advantageously, timing of the parallelized optical link calibration is independent of a number of spans in the optical section.

Abstract: A system can include a unit cell of a ring modulator of a coarse wavelength division multiplexing (CWDM) optical link. The unit cell includes a ring resonator including a ring waveguide configured to receive, via a first bus waveguide, an optical signal, and modulate the optical signal to generate a modulated optical signal. The unit cell further includes a multiplexer, disposed between the first bus waveguide and a second bus waveguide, configured to filter the modulated optical signal.

Abstract: A Luneburg lens-based radio head for a receiver, transmitter or transceiver may comprise a Luneburg lens or equivalent lens and a plurality of electro-optic modules. The electro-optic modules provide a conversion between RF sector beam at the Luneburg lens and an optical signal containing the information of the RF sector beam. When the radio head comprises a receiver, up-conversion modules formed on a surface of the Luneburg lens. Each of the up-conversion modules includes an antenna element, which picks up the incoming focused RF beam and converts it to an RF electric signal, and an electro-optic modulator that up-converts the RF electric signal to the optical domain by modulating an optical carrier with the RF electrical signal provided by the antenna element. The up-converted optical signal may be transmitted to a processor via an optical fiber for downstream processing.

Abstract: A method is provided for securement of a network of optical fibers against attempts to detect sounds such as private conversations emitted in the vicinity of the fiber network such as in a secure room. The cable entering the room contains a plurality of fibers some of which have data and some are unused. It has been found that the sensitivity of systems such as DAS monitoring systems can detect such conversations from the vibration of the fibers in the vicinity. The method includes monitoring at least some of the fibers for detecting transmission therealong of light signals used for monitoring of fiber vibration which provide information on the sounds. An indication alert is emitted when detected of an intrusion attempt. A jamming signal can be transmitted along the detected fiber to prevent the monitoring. The monitoring and jamming can take place at a patch panel where the fibers are connected.

Abstract: A disclosed optical system comprises a repeater disposed between a first span and a second span of an optical cable and a node receiving an optical signal from the first span and transmitting a reflection to the first span. The node comprises a transmitter coupled to the first span to transmit the optical signal, transmit pulses having a test subcarrier and a tone, and provide a reference pulse; a receiver to receive the reference pulse and the reflection and passing a filter spectrum; and a DSP to: determine a first dispersion based on a first phase of the reference pulse and on a second phase of the reflection of a first pulse; determine a second dispersion based on a third phase of the reference pulse and a fourth phase of the reflection for a second pulse; and determine a first span seismic pressure based on the first and second dispersion.

Abstract: According to an aspect of an embodiment, an optical line terminal (OLT) configured for downstream transmission in a passive optical network (PON) may comprise a processing device and a transceiver. The processing device may be configured to: generate a first downstream signal for transmission on a first channel at a first signal level, and generate a second downstream signal for transmission on a second channel at a second signal level. The first signal level may be greater than the second signal level. The PMD transmitter may be configured to transmit a combined downstream signal comprising the first downstream signal and the second downstream signal. The first transmit power of the first downstream signal may be selected based on a comparison to a second transmit power of the second downstream signal to facilitate reception of the first downstream signal from the combined downstream signal at an optical network unit (ONU).

Abstract: A method for phase compensation in an optical communication network includes (1) modifying a modulated signal according to one or more correction factors to generate a compensated signal, to compensate for phase rotation, (2) modulating a magnitude of an optical signal in response to a magnitude of the compensated signal, and (3) modulating a phase of the optical signal, after modulating the magnitude of the optical signal, in response to a phase of the compensated signal.

Abstract: An optical communication system includes N optical modules at the local end. Each optical module includes a first optical interface and a second optical interface. A first optical interface of a first optical module in each of the N optical modules at the local end is connected to a peer end through a common optical fiber. A second optical interface of an ith optical module in the N optical modules at the local end is connected to a first optical interface of an (i+1)th optical module in the N optical modules at the local end, and i=1, 2, . . . , N?1.

Abstract: Techniques for driving a directly modulated laser whilst correcting non-linearities an optical output waveform, based on generating a modulating current waveform that approximates an ideal modulating current that produces a linear optical output waveform. The techniques enable useful, practical approximations to the ideal modulating current to be determined.

Abstract: A gain equalization apparatus according to an example embodiment includes a first path including a gain equalizer configured to correct a tilt of an input optical signal, a second path including a through-fiber configured to transmit the input optical signal therethrough as it is, an optical switch capable of switching between the first path including the gain equalizer and the second path including the through-fiber, at least one memory configured to store instructions, and at least one processor configured to execute the instructions to control the switching of the optical switch. By this configuration, a gain equalization apparatus and a method for equalizing a gain capable of reducing power consumption and suppressing an increase in optical loss while improving reliability are provided.

Abstract: Provided is an optical transmission system including: an optical transmission apparatus; an optical reception apparatus; a communication device that is a delay measurement target; and a transmission device that transmits a signal between the optical reception apparatus and the communication device, in which the optical transmission apparatus includes a main signal transfer unit that transmits a main signal, the transmission device transmits, to the optical reception apparatus, a first main signal transmitted from the optical transmission apparatus and transmitted via the communication device and a second main signal transmitted from the optical transmission apparatus and not transmitted via the communication device, and the optical reception apparatus includes a reception processing unit that measures a delay occurring in the communication device by using the first main signal and the second main signal transmitted from the transmission device.

Abstract: A backbone network (100) for use in an optical wireless communication system comprises one or more local switches (200) and one or more optical access points (300), APs, wherein local switches (200) are configured to provide to optical APs (300) connections to an external network. Each local switch (200) comprises a first type optical front end (210), OFE, having a rotatable orientation and a beam angle not larger than 60 degrees, and a second type OFE (230) having a 360-degree beam angle on the rotation plane of the first type OFE. Each optical AP comprises an OFE (310) having a rotatable orientation and a beam angle not larger than 60 degrees. The pairing and beam alignment between the first type OFE of a local switch and the OFE of an optical AP is achieved via the assist of the second type OFE of the local switch.

Abstract: A long-distance DWDM lightwave transmission system operating in the 2000 nm wavelength region is proposed that is based on the utilization of hollow core fiber configured to exhibit low loss (e.g., on the order of 0.02 dB/km) in combination with a hybrid TDFA/HDFA repeater device. Multiple concatenated spans of the combination of the hollow core fiber and hybrid TDFA/HDFA repeater device are able to provide communication over path lengths in excess of 10,000 km without the need for electronic regeneration of the propagating signals. In one case, the hollow core fiber is configured as a double-nested anti-resonant nodeless fiber (DNANF) with the number of nested structures and their various parameters optimized to provide the low loss operation in the 2000 nm region.