A horizontal machining center includes: a table driven in first and second directions (directions indicated by arrows 530p and 530q, respectively) allowing the table to approach and move away from a spindle, respectively; a magazine having a plurality of tool gripping claws; and a coupling mechanism for coupling the table and the magazine together and moving the magazine in one of the first and second directions when the table is driven in the other of the first and second directions. When a tool attached to the spindle is removed from the spindle, the table is driven in the first direction, and when a tool accommodated by the magazine is attached to the spindle, the table is driven in the second direction. A horizontal machining center having a simple structure and prevented from having a bulky structure can thus be accomplished.

Disclosed in an automatic tool changer in which the tool changing time can be shortened by increasing overlapping operations of the turning operation and the axial advancing/retracting operation of a replacement arm. An arm driver (32) is so constituted that the driver performs overlapping operations such that at least a part of the operation for turning a replacement arm (23) by 180° and the operation for advancing/retracting the replacement arm in the axial direction in order to insert or withdraw a tool (37) are performed simultaneously and in parallelism with each other. When the replacement arm (23) is advanced/retracted in the axial direction in order to insert or withdraw a tool, the replacement arm (23) is turned by a predetermined distance in a direction reverse to the direction (so called “normal direction”) for turning the arm by 180° in parallelism with the advancing/retracting operation, and thereafter, the replacement arm (23) is turned in the normal direction.

A method for processing workpieces with a laser processing machine including a laser processing head having a nozzle receiving member configured to receive a laser nozzle. The method includes holding a workpiece on a workpiece support plane of a workpiece support, transferring a laser nozzle between a nozzle magazine of a nozzle changing device located at a first side of the workpiece support and a nozzle receiving member of the laser processing head located at a second side of the workpiece support such that the laser nozzle is assembled on or disassembled from the nozzle receiving member, and moving the laser nozzle through a through-opening defined in the workpiece support along a transverse direction to the workpiece support.

There is provided a tool holding and conveying chain adapted to securely lock and position a tool pot, i.e., a connecting pin, to a pin hole of either an outer or inner link plate so that the tool pot does not to turn and to achieve steady and smooth attachment and removal of a tool in and out of the tool pot with a simple attachment structure. The tool pot has a pair of positioning flat portions formed by cutting a link plate attaching outer circumferential region of the tool pot and the outer link plate has a pair of positioning cooperative flat portions formed so as to bulge out of an inner circumference to a center of a pin hole. The positioning flat portions of the tool pot is fitted into and locked by the positioning cooperative flat portions when the tool pot is attached in the link plate.

The invention relates to a machine tool (1), comprising a plurality of fixed tool spindles (3) and such that can optionally be displaced from a retracted idle position to an extended working position and can be positioned at different positions in a frame-like rack (2), and a workpiece carrier (4) with at least one workpiece holder (5), with the workpiece (4) carrier being movable at least in several axes in a translational manner and preferably also in a rotational manner. In order to provide advantageous constructional conditions it is proposed that at least one of the tool spindles (3) is associated with a tool magazine (7) plus tool changer (8).

An automatic collimator changer of a radiation treatment system.

A system for loading/unloading sheets is disclosed, some of which also being of metal, and handling method thereof, serving a laser cutting center. The system includes a pair of rails (1, 2), supported at a preset height above a feeding tray (T) of the cutting center, whereon at least one Cartesian robotized hand is movably mounted, capable of moving along horizontal axes X and Y as well as along a vertical axis Z, mutually orthogonal, and including at least two bridge cranes (3, 4) sliding along the rails (1, 2) each of which supports at least one pair of robotized hands (5-8), and the robotized hands (5-8) have an electromagnetic pick-up head which may be coupled with a suction-cup device (103). Feeding tray (T) consists of bars whereon small tesserae (204) of ceramic material are fitted.

There is provided a component mounting apparatus, which includes: a nozzle which sucks a component; a nozzle supporting member, on which the nozzle is installed, which moves in a vertical direction with respect to an upper surface of a substrate on which the component sucked at the nozzle is mounted; an optical system which captures an image of a leading edge portion of the nozzle where the component is sucked in a component mounting operation, from a side direction, such that an optical axis of the optical system is inclined at a predetermined angle with respect to a sucking surface of the nozzle; and an analyzer which analyzes the image of the leading edge portion to determine whether a sucking state of the component sucked by the nozzle is normal or abnormal.

A carriage is moved in a direction including a Y axis component in order to move a turning process tool that is attached to a tool spindle along a horizontal line that is perpendicular to a Z axis, and thus, a turning process is carried out on a workpiece which is attached to a workpiece spindle.

A device and method for adjusting the magnetic strength of a magnetic end effector for lift systems is described. The magnetic end effector is capable of lifting discriminate payloads by selectively varying the strength of the magnetic forces output by the magnetic end effector. An actuator can be operatively coupled to the variable strength magnet end effector, wherein the actuator is selectively actuatable to control the adjustment of the variable strength magnet. The actuator may also be configured to maintain the variable strength magnet at a desired magnetic force output strength once achieved for any given amount of time.

A subsea tool changer comprises a housing; a rotatable carousel rotatably mounted within the housing and adapted to receive a plurality of selectively removable tools; a tool changer that can select a predetermined one of the plurality of tools from the carousel; and a power drive adapted to provide a predetermined function to a tool selected by the tool changer, the power drive further comprising a first power drive interface. In typical use, a selectively removable tool is placed onto the rotatable carousel which is rotated so that a desired selectively removable tool is positioned adjacent to a tool driver which is then mated with the desired selectively removable tool. The tool changer and mated selected removable tool are moved outward toward an outer boundary of the housing and the tool changer extended at least partially outside the housing outward towards a predetermined tool working position. The tool changer is then pivoted to position the selected removable tool to its predetermined tool working position.

A cutting device includes a support base, a first slide module, a second slide module slidably connected to the first slide module, and a cutting module. The support base includes a support surface and a slide portion on the support surface. The first slide module is slidably positioned on the slide portion. The sliding direction of the second slide module is perpendicular to the sliding direction of the first slide module. The cutting module includes a fixed frame fixed on the second slide module, a driving device fixed on the fixed frame, and a cutter connected to the driving device. The driving device drives the cutter to rotate around a central axis of the cutter and move up and down along the central axis. The central axis is perpendicular to the support surface. The cutter includes a hollow cylindrical blade. An end surface of the blade faces the support surface.

Device for managing the electrodes for electrical discharge machining EDM machine tools comprises at least one magazine (1) that has a series of individual housings (33) designed to accept and hold exchangeable elements (5) consisting of electrodes (6, 22) mounted on an electrode holder (11a, 11b), and a changer device (2) equipped with a gripper (2) intended to move the exchangeable elements (5) from the individual housings (33) towards the machine and vice versa. A first adapter piece (21) is associated with each of the exchangeable elements (5). This adapter piece (21) surrounds the electrode holder (11a, 11b) and is gripped around its periphery by the gripper (9) of the changer (2) so as to guarantee that the exchangeable element (5) is held precisely. The device further comprises a second adapter piece (32) associated with each of the individual housings (33) of the magazine (1) that are likely to be used.

A head tool changer for use with a deposition-based digital manufacturing system, the head tool changer comprising a tooling unit configured to retain a deposition head, a grip unit configured to engage with tooling unit and to relay electrical power to the tooling unit, and a master unit operably mounted to a gantry and configured to engage with the tooling unit and to relay electrical power to the tooling unit.

A machine tool is provided with a chain-type bit-storing apparatus which includes a frame, two sprockets, a chain and a pivoting unit. The frame includes a cutout. The sprockets are placed in the frame. The chain is driven by the sprockets. The chain includes links each including a socket for containing a bit, two plates for supporting the socket, first and second blocks placed between the plates, first and second bearing units for rotationally supporting the first and second blocks on the plates, and a connecting unit for pivotally connecting the first block thereof to the second block of an adjacent link. The pivoting unit is used to pivot the socket of a selected one of the links to move an open end of the socket out of the frame through the cutout.

A welding tip replacement apparatus is used for a welding torch that includes a tubular tip connection body, a tubular retaining member fitted over the tip connection body, and a tubular welding tip fitted within the tip connection body, the welding torch being configured such that displacing the retaining member toward the proximal end of the tip connection body along the axis of the tip connection body causes the welding tip axially fastened to the tip connection body to be released. The apparatus includes a first grasping mechanism grasping the retaining member, a second grasping mechanism grasping the welding tip protruding from the retaining member in a direction away from the distal end of the tip connection body, a first driving mechanism driving the first grasping mechanism axially, and a second driving mechanism driving the second grasping mechanism axially.

A section member drilling or milling machine comprises a machine bed for supporting a workpiece to be drilled, the machine bed including guides for controllably sliding thereon a support comprising precision vertical guides thereon a platform is engaged, the platform comprising parallel horizontal guides slidably supporting a carriage, in turn supporting a cantilever arm, including a driving motor for controllably driving a drilling and milling tool along parallel guides of the cantilever arm.

A tool changing device for a cutting head of a machine for cutting flat glass sheets, the tool changing device comprising: a bridge; a carriage for supporting the cutting head, the carriage being slidingly attached to the bridge for translation along the bridge; an electric motor that provides for translational motion of the carriage with respect to the bridge; and a tool supporting slider, which is configured to support a plurality of tools such that the tools can be automatically exchanged between the tool supporting slider and the cutting head, the tool supporting slider coupled, by way of reversible fixing elements to the cutting head supporting carriage during work by the cutting head, and wherein the tool supporting slider is uncoupled from the cutting head supporting carriage during tool changing operations.

Provided is a module for automatic tool exchange device of novel structure wherein electric signals can be transmitted with high reliability while preventing transmission efficiency from deteriorating between a first coupling member and a second coupling member. An electromagnetic shielding member is arranged on an outer circumference of a core member except for a transmission surface, a gap member having electromagnetic shielding effect lower than that of the electromagnetic shielding member is interposed between the core member and the electromagnetic shielding member, and a first module and a second module are provided, respectively, with coil units equipped with coil heads which are constituted to include a coil member, the core member and the gap member.

A tool radius adjusting device executes an operation for adjusting the tool radius of a boring holder in parallel with execution of a machining program for executing an operation of a spindle head and an operation of a tool changer. A carrier control unit determines whether the tool changer is executing a tool changing process. When the tool changing process is not being executed, the carrier control unit allows the carrier device to execute an operation for picking the boring holder out from the tool magazine and an operation for returning the boring holder, of which the tool radius has been adjusted, to the tool magazine.

In a multitasking machine tool, a first tool post including a tool spindle configured to allow a tool to be detachably attached thereto is configured to be slidable in predetermined directions, while a second tool post is configured to allow a tool to be detachably attached thereto. A tool-change part includes at least one gripper configured to hold a tool to be attached to the second tool post. An automatic tool changer is configured to detachably attach the tool-change part (as well as to change the tool installed) to the tool spindle of the first tool post positioned in a first tool-change region. Change of the tool attached to the second tool post is carried out by a motion (sliding and/or rotation of the tool spindle) of the first tool post (with the tool-change part attached to the tool spindle thereof) located in a second tool-change region.

In a combination machining lathe, a workpiece holding device holds a workpiece in a manner that permits the workpiece to rotate around an axis parallel to a direction of a horizontal Z axis. A tool post holds a tool that comprises a holder and a bit. The tool held by the tool post is indexed to a position in which the longitudinal axis of the holder is parallel to an X axis direction. The bit of the tool held by the tool post is angled such that a longitudinal axis of the bit is disposed in a position tilted away from the X axis direction closer to a horizontal axis in a plane containing the X axis and the Y axis. A turning operation is performed while the tool and/or the workpiece are moved relative to each other in a direction of the longitudinal axis of the bit.

The disclosure provides a method and a system for detecting a fiber fault in a Passive Optical Network (PON). The system comprises an optical path detection device, a Wavelength Division Multiplexing (WDM) coupler, a wavelength selection coupler, a branch fiber selector and a wavelength selection router. The detection system is attached to an original PON system, without influencing the operation of the original system while performing the detection. With the disclosure, the problem of being unable to determine whether there is a fault in a branch fiber due to the loss of an optical path detection reflection signal is solved, the branch fiber with a fault can be quickly located and fixed, thus the operational and maintenance costs of an operator are reduced.

A system and method are disclosed for transporting deterministic traffic in a gigabit passive optical network. A system that incorporates teachings of the present disclosure may include, for example, an Optical Line Termination (OLT) for exchanging data traffic in a Gigabit Passive Optical Network (GPON) having a controller programmed to generate a timeslot schedule for transport of a desired bandwidth of constant bit rate (CBR) data traffic by selecting one or more timeslots from periodic frame clusters operating according to a GPON Transmission Convergence (GTC) protocol. Additional embodiments are disclosed.

A method and apparatus for controlling update of digital pre-distortion (DPD) coefficient is provided. The apparatus is applicable to a digital power control system, wherein the apparatus comprises: an update controlling unit configured to determine a group of fully-trained DPD coefficients among a plurality of DPD coefficients; and a DPD coefficient generating unit configured to update adaptively the group of fully-trained DPD coefficients according to the result of judgment of the update controlling unit. The DPD coefficients are allowed to be updated after being judged as being able to be fully trained according to power distribution information of DPD input signals, or according to address distribution information of an LUT, or according to average power of output of an HPA; otherwise, they may not be updated, thereby efficiently preventing DPD abnormality resulted from unfull training of coefficients in being updated.

The disclosure discloses an apparatus and method for rerouting multiple traffics. The apparatus includes a path computation unit and a traffic path incorporation unit, the path computation unit forwards a received uniform route computation notification message including multiple pieces of failed traffic connection information to the traffic path incorporation unit, and also forwards a route inquiry request transmitted from the head node of the fault traffic to the traffic path incorporation unit; the traffic path incorporation unit analyzes and detects the failed traffic connection information according to traffic incorporating and route inquiry statistic algorithm, and uniformly obtains and records the recovery route information from the path computation unit; when receiving the route inquiry request forwarded by the path computation unit, the traffic path incorporation unit is further configured to search the record according to the route inquiry request, and return the found corresponding recovery route information to the head node which requests the recovery through the path computation unit. The disclosure uses a incorporating and uniform route inquiry method, the resource loss of the path computation unit is reduced, and the efficiency of link restoration is improved.

An optical transceiver has a communications mode and an optical time domain reflectometer (OTDR) mode. The transceiver comprises a transmitter channel and a receiver channel operable, in the communications mode, to respectively transmit and receive communications signals through respective external optical fibers. The transceiver also comprises a guide arrangement for guiding, in the OTDR mode, a reflected OTDR signal along a path from the transmitter channel into the receiver channel. A method of obtaining test data for an optical fiber in an optical data communications subsystem is also disclosed.

Embodiments of the present disclosure provide methods for allocating bandwidth to a plurality of traffic containers of a passive optical network. The method comprises receiving upstream data from a plurality of traffic containers of the passive optical network and passing the upstream data to a traffic manager. The method further comprises dynamically changing the allocated bandwidth based at least in part on the amount of the upstream data stored in one or more queues of the traffic manager.

The invention provides optical interconnects of data-processing cores of multicore chips by means of digital planar holographic microchips. The method comprises delivering “N” laser lights to “N” data-processing cores on the host chip, coding the obtained optical signals by modulating them with the core-generated data, and then delivering the modulated and coded optical signals to a holographic microchip formed on the same substrate of the host chip as the data-processing cores, splitting the modulated and coded optical signals into (N−1)N modulated optical copy signals, delivering the copy signals to all data-processing cores except the one that generates the copy signals, and decoding the data obtained from the output signals delivered to the processing cores by the receivers. The method is efficient in that it allows replacing electrical interconnects between the cores with optical interconnects and can be matched to current semiconductor production technology.

A method of controlling consumer devices using an infrared dongle coupled to a mobile device includes receiving power for the infrared dongle from the mobile device. The infrared dongle includes an infrared transmitter coupled to a microcontroller. One or more instructions are received in the microcontroller from the mobile device. The received one or more instructions are generated from codes stored in a memory of the mobile device. In response to the receiving, one or more infrared signals are transmitted via the infrared transmitter to at least one of the consumer devices.

A transmitter and a receiver for an optical telecommunication system of the WDM type are disclosed. In one aspect, the transmitter uses a chromato-temporal encoder which, with each block of symbols to be transmitted, associates a code matrix, where each element of the matrix corresponds to a wavelength and a use of the channel. The transmitter includes multiple modulators, where each modulator modulates a laser beam at a wavelength during a use of the channel by an element corresponding to the code matrix. The beams modulated in this manner are multiplexed in an optical fiber. Another embodiment using both a wavelength and a polarization encoding is also proposed.

An undersea long-haul transmission system includes an optical fiber transmission span and a coherent detection and digital signal processing module for providing dispersion compensation. The transmission span includes at least one fiber pair comprising substantially equal lengths of a positive-dispersion first fiber and a negative-dispersion second fiber that are configured to provide a signal output at transmission distances greater than 10,000 km, in which the combined accumulated dispersion across the operating bandwidth does not exceed the dispersion-compensating capacity of the coherent detection and digital signal processing module. Further described is a fiber for use in an undersea long-haul transmission span. At a transmission wavelength of 1550 nm, the fiber has a dispersion coefficient in the range of −16 to −25 ps/nm·km, and a dispersion slope in the range of 0.04 to 0.02 ps/nm2·km.

A fiber optic data transmission system includes an optical fiber and a data transmitter having a first laser having a first wavelength, a first phase modulator for phase modulating light from the first laser as a function of a first data input stream so as to create a first phase-modulated output data stream, a second laser having a second wavelength different from the first wavelength, and a second phase modulator for phase modulating light from the second laser as a function of a second data input stream so as to create a second phase-modulated output data stream. The transmitter also includes a combiner combining the first and second output data streams into a phase-modulated optical signal for transmission over the optical fiber.

Methods and apparatus related to the detection of low-rate visible light communication (VLC) signals and the recovery of information communicated by the VLC signals are described. Various methods and apparatus are well suited for embodiments in which a device, e.g., a smartphone, including a camera which uses a rolling shutter. The rolling shutter facilitates the collection of different time snapshots of a received low rate time varying VLC signal with different pixel rows in the image sensor of a frame corresponding to different time snapshots. In some embodiments, demodulation is used to recover and identify a single tone being communicated in a frame from among a plurality of possible alternative tones that may be communicated, each different tone corresponding to a different set of information bits.

Provided is a polarization separation device which converges filter coefficients used in polarization separating process more quickly. The polarization separation device according to the present invention comprises: a first filter means 11 which applies filtering process on each of first and second input signals, which are detected from an received optical signal, with elements of a characteristic matrix representing the inverse characteristics of an optical transmission path as filter coefficients, and uses each of the filtered signals to output a first output signal; a second filter means 12 which applies filtering process on each of the first and second input signals with the other elements of the characteristic matrix as filter coefficients, and uses each of the filtered signals to output a second output signal; a filter coefficient update means 13 which updates the first filter coefficients using a relation between the elements of the characteristic matrix so as to further reduce both error signals of the first and second output signals; and a filter coefficient update means 14 which updates the second filter coefficients using the relation between the elements of the characteristic matrix so as to further reduce both error signals to the first and second output signals.

An optical transceiver that attenuates the EMI radiation leaked therefrom is disclosed. The optical transceiver includes a top cover and the bottom base to form a cavity into which a TOSA, a ROSA, and a circuit are set. At least one of the top cover and the bottom base provides a combed structure in a rear portion of the optical transceiver, where the combed structure has a plurality of T-shaped fins to attenuate the EMI radiation.

This invention concerns real-time multi-impairment signal performance monitoring. In particular it concerns an optical device, for instance a monolithic integrated photonics chip, comprising a waveguide having an input region to receive a signal for characterization, and a narrow band CW laser signal. A non-linear waveguide region to mix the two received signals. More than one output region, each equipped with bandpass filters that extract respective discrete frequency bands of the RF spectrum of the mixed signals. And, also comprising (slow) power detectors to output the extracted discrete frequency banded signals.

An optical transceiver that reduces the EMI radiation leaked therefrom is disclosed. The optical transceiver includes a top cover and the bottom base to form a cavity into which a TOSA, a ROSA, and a circuit are set. The top cover provides a combed structure in a rear portion thereof, where the combed structure has a plurality of fins with a distance preferably less that quarter wavelength λ/4 of the noise wavelength to be reduced. The combed structure operates as a short stub for the electromagnetic wave traveling longitudinally in the cavity.

A WDM optical signal is transmitted through a tunable optical filter and is polarization-nulled to find optical signal to noise ratio of individual WDM channels. The polarization nulling can be performed using a heuristic multipoint extrema search method, such as Nelder-Mead method. A plurality of checkpoints can be included in the search to verify the progress and to improve the overall robustness of a real-time polarization nulling.

The present invention refers to a method for adjusting power levels of channels (15) in an optical link (7) of an optical network comprising at least one optical amplifier (9) wherein the power distribution among the channels (15) of the optical link (7) is achieved in function of: target power levels based on the features of corresponding connections and of link physical features,total available power in said at least one amplifier (9),features of control means allowing the power distribution, and wherein for a channel corresponding to a connection having a higher vulnerability characterizing parameter, the tolerated difference between an actual channel power level and the target power level is lower than for a channel corresponding to a connection having a lower vulnerability characterizing parameter.

An optical transport network system includes a plurality of NEs, each transmitting wavelength-multiplexed optical signals. Each NE includes a routing information DB that is used to store reachable area information, which contains identifiers of other NEs in a range within which the optical signals can be transmitted from the own NE without using an REG. A FROM NE includes a path candidate searching unit that searches for a plurality of path candidates for transmitting optical signals from the FROM NE to a TO NE. The TO NE includes a path selecting unit that selects a path for transmitting optical signals from among a plurality of path candidates. The path selecting unit obtains the number of times for which the REG is used for each of the plurality of path candidates; and, based on each number of times that is obtained, selects a path for transmitting the optical signals.

Additional bandwidth is provisioned to layer 2/3 networks by initially provisioning optical wavelength channels to meet incremental needs for additional capacity. When bandwidth requirements grow large enough, a wavelength-sized channel is provisioned to meet the bandwidth needs, and the previously provisioned optical wavelength channels are freed up to be reused for additional growth. The optical wavelength channels may be channelized VLANs mapped to resizable optical channel data units such as ODUflex units.

This invention relates to provisioning wavelength-selective switches and reconfigurable optical add-drop multiplexers to minimize the bandwidth narrowing effect from the optical filters. Novel architectures and methods are disclosed that can significantly reduce bandwidth-narrowing on channels in a reconfigurable WDM network where a large number of optical filter elements are cascaded. Instead of blocking unused channels as in the prior art, unused channels are selectively provisioned depending on the state of their adjacent channels. Unused adjacent channels of an active channel are provisioned to follow the same path as the active channels. As each channels is deployed, the channel frequency is selected so as to minimize bandwidth narrowing.

A method for adjusting an optical signal includes determining a polarization dependent loss (PDL) value associated with the optical signal, determining an angle between the optical signal and one or more axes of PDL, determining an amount of nonlinear phase noise due to PDL and nonlinear effects upon the optical signal based upon the PDL value and the angle, determining a phase rotation based upon the amount of nonlinear phase noise, and applying the phase rotation to the optical signal.

An optical module that outputs a wavelength multiplexed optical signal is disclosed. The optical module provides at least first to third optical source, a wavelength multiplexer, a polarization rotator, and a polarization multiplexer. The optical sources each outputting first to third optical signals with a wavelength different from others. The wavelength multiplexer multiplexes the first optical signal with the third optical signal. The polarization rotator rotates the polarization vector of one of the multiplexed first and third optical signals and the second signal by substantially 90°. The polarization multiplexer multiplexes the polarization rotated optical signal with the second optical signal.

Optical fiber-based distributed communications systems that provide and support both RF communication services and digital data services are disclosed herein. The RF communication services and digital data services can be distributed over optical fiber to client devices, such as remote antenna units for example. In certain embodiments, digital data services can be distributed over optical fiber separate from optical fiber distributing RF communication services. In other embodiments, digital data services can be distributed over common optical fiber with RF communication services. For example, digital data services can be distributed over common optical fiber with RF communication services at different wavelengths through wavelength-division multiplexing (WDM) and/or at different frequencies through frequency-division multiplexing (FDM). Power distributed in the optical fiber-based distributed communications system to provide power to remote antenna units can also be accessed to provide power to digital data service components.

An optical transceiver of one embodiment includes a transmitter optical subassembly to transmit an optical signal, a receiver optical subassembly to receive an optical signal, a mother board, a daughter board, and a housing. The mother board mounts electronic circuits that electrically communicate with the optical transmitter optical subassembly and the receiver optical subassembly. The daughter board mounts other electronic circuits that electrically communicate with the optical transmitter optical subassembly and the receiver optical subassembly. The daughter board has an extra area mounting a portion of the other electronic circuits. The housing defines a space for installing the optical transmitter optical subassembly, the receiver optical subassembly, the mother board, and the daughter board. The extra area is disposed outside the space.

The invention relates to embedding data symbols of a data signal into a luminance output of an illumination device. The device includes a controller configured for receiving a first base pattern and a second base pattern within a frame period, and generating a shifted second pattern by phase shifting the second base pattern within the frame period with respect to the first base pattern in response to the data signal such that the data symbols are embedded in the luminance output of the device. The device also includes a first light source configured to generate a first luminance output in response to the first base pattern and a second light source configured to generate a second luminance output in response to the shifted second pattern. The first and second luminance outputs have different output spectra and the luminance output of the illumination device comprises both the first and second luminance outputs. With this approach, the short-time average light output of the illumination device remains constant, decreasing the visible flicker and allowing the use of lower switching frequencies relative to the prior art approaches.

A repeater includes a reception part configured to receive an optical signal transmitted by wavelength division multiplexing from a preceding repeater in a path from a source to a destination; a determination part configured to determine the channel allocation of the signal received by the reception part by determining a bit rate and a modulation technique with respect to each of channels in the received signal; and a detection part configured to detect a prohibited channel not to be included in the optical signal to be transmitted from the repeater, based on the channel allocation and a predetermined criterion.

An optical receiver circuit is disclosed in which a number of electrical signals are processed to extract data encoded therein. The electrical signals may be compared during the process to selectively remove one or more waveforms from one or more corresponding electrical signals. Various data signals, each including one or more waveforms, may then be processed to extract the encoded data. The optical receiver circuit reduces, or eliminates, electrical offsets which may be present in one or more of the electrical signals to reduce corresponding errors in the encoded data signals.