The present invention provide a two-component anti-seizure agent for hot metal working process comprising the first aqueous solution and the second aqueous solution, wherein the first aqueous solution contains 10˜30 mass % of sodium silicate equivalent to anhydride to 100 mass % of total mass of the first aqueous solution, and the second aqueous solution contains at least one kind selected from a group consisting of: an organic acid and water-soluble amine salts thereof, an inorganic acid and water-soluble amine salts thereof, a water-soluble amine, a water-soluble alcohol, and a water-soluble metal chloride. When the two-component anti-seizure agent is applied onto disk-roll type guide shoes, it can be provided and maintained on the circumferential surface of the disk-roll type guide shoes without washed away by rolls' cooling water. Thereby, the anti-seizure agent does not adhere to rolls and the rolls and a pipe material do not cause slippage each other. Thus, it is capable to carry out piercing-rolling of the pipe material.

The invention relates to a machine part comprising a first physical component, wherein: the first physical component is configured for moving relative to a second physical component; the first physical component has a first surface with a contact area for physical contact with the second physical component; the first physical component is shaped spatially complementarity to the second physical component at the contact area, and a polyelectrolyte layer is present on the first surface at a location of the contact area. The invention further relates to a machine comprising the present machine part and the second physical component. In addition, the invention relates to the use of a polyelectrolyte layer to reduce the friction between the first physical component and the second physical component, and a rolling-elements bearing.

The lubricating base oil of the invention is characterized by satisfying at least one of the following conditions (a) or (b). (a) A saturated compound content of 95% by mass or greater, and a proportion of 0.1-10% by mass of cyclic saturated compounds among the saturated compounds.(b) The condition represented by the following formula (1). 1.435≦n20−0.002×kv100≦1.450 (1) wherein n20 represents the refractive index of the lubricating base oil at 20° C., and kv100 represents the kinematic viscosity (mm2/s) of the lubricating base oil at 100° C.

A novel molybdenum dithiocarbamate composition is produced by preparing a di-tridecylamine (DTDA) intermediate from a butylene feedstock comprising greater than 50% 2-butylene, and preparing a molybdenum dithiocarbamate composition from the DTDA intermediate. The resulting molybdenum dithiocarbamate composition are according to formula (1), wherein R1 to R4 are C11-C14 isoalkyl groups, and X represents oxygen and/or sulfur atoms, and R1 to R4 comprise, on average, greater than 98% C13:

The invention provides a grease composition for a hub unit bearing employing an angular contact ball bearing, containing (a) as a thickener a mixture of diurea compounds represented by formula (I): R1—NHCONH—R2—NHCONH—R1, formula (II): R1—NHCONH—R2—NHCONH—R3, and formula (III): R3—NHCONH—R2—NHCONH—R3 wherein R1 is cyclohexyl group, R2 is a divalent aromatic hydrocarbon group having 6 to 15 carbon atoms, R3 is a straight-chain or branched alkyl group having 12 to 20 carbon atoms, and (R1/(R1+R3))×100=85 to 95 mol %; (b) a base oil; (c) a molybdenum dialkyldithiocarbamate; and (d) a calcium sulfonate. The grease composition of the invention, when used in the hub unit bearing, shows minimum leakage, excellent anti-flaking properties and satisfactory bearing lubrication life.

Corrosion by ammonia/amine salts in hydrocarbon streams such as distillation overhead streams that contain a mineral acid and water can be prevented, avoided or minimized by adding certain strong amines to the streams. The amines have a pKa between about 10.5 to about 12 and include, but are not necessarily limited to, dimethylamine, diethylamine, dipropylamine, diisopropyl-amine, di-n-butylamine, diisobutylamine, di-sec-butylamine, di-tert-butylamine, pyrrolidine, piperidine, and combinations thereof. If the hydrocarbon stream further includes a nitrogen-containing compound such as ammonia, a tramp and/or a residual amine which can form a corrosive salt with the mineral acid, then the added amine is a stronger base than the tramp or residual amine, if present. The amount of added amine is greater than total amount of nitrogen-containing compound, so that any corrosive salts formed are less corrosive than the salts that would otherwise form from the ammonia and/or tramp amine.

Lubrication additives of the current invention require formation of emulsions in base lubricants, created with an aqueous salt solution plus a single-phase compound such that partitioning within the resulting emulsion provides thermodynamically targeted compounds for boundary layer organization thus establishing anti-friction and/or anti-wear. The single-phase compound is termed “boundary layer organizer”, abbreviated BLO. These emulsion-contained compounds energetically favor association with tribologic surfaces in accord with the Second Law of Thermodynamics, and will organize boundary layers on those surfaces in ways specific to the chemistry of the salt and BLO additives. In this way friction modifications may be provided by BLOs targeted to boundary layers via emulsions within lubricating fluids, wherein those lubricating fluids may be water-based or oil-based.

Various esterified alkyl ketal ester or hydroxyalkyl ketal ester products are useful as components of organic polymer compositions. The ketal esters are produced in certain transesterifications between alkyl ketal esters and/or hydroxyalkyl ketal esters and polyols, aminoalcohols, polyamines, and/or polycarboxylic acids. The products are excellent plasticizers for a variety of organic polymers, notable poly(vinyl chloride) plastisols. The products are also very good lubricants for many lubrication applications.

A water-soluble metalworking oil agent is provided by blending the following components A, B, C and D: (A) at least one of a condensed fatty acid obtained by dehydration-condensing a ricinoleic acid, and a condensed fatty acid obtained by dehydration-condensing a monovalent carboxylic acid with an alcoholic hydroxyl group of a condensed fatty acid obtained by dehydration-condensing a ricinoleic acid;(B) an ester compound provided by a dehydration condensate of a monovalent or multivalent alcohol and a monovalent carboxylic acid;(C) an amine compound; and(D) water. A blend ratio of the component A is 10 mass % or more of a total amount of the oil agent and a blend ratio of the component B is 5 mass % or more of the total amount of the oil agent.

It is known by the inventor that a universal synthetic lubricant additive that can greatly enhance the performance standards of existing lubricants, petroleum based or synthetic, imparts a new and desirable property not originally present in the existing oil or it reinforces a desirable property already possessed in some degree can greatly benefit the consumer. Although additives of many diverse types have been developed to meet special lubrication needs, their principal functions are relatively few in number. This universal synthetic lubricant additive (invention) with micro lubrication technology, when used as directed will reduce the oxidative or thermal degradation of the host oil, substantially reduce the deposition of harmful deposits in lubricated parts, minimize rust and corrosion, control frictional properties, reduce wear, temperature, sludge, varnishes and prevent destructive metal-to-metal contact, reduce fuel consumption and harmful emissions while improving performance through increased horsepower and torque.

Provided are a lubricant composition capable of reducing friction between sliding parts at least one of which contains an aluminum-based material in a lubrication section, and a method for lubricating an aluminum-based member with the composition. The lubricant composition is for use in a lubrication section having sliding parts at least one of which contains an aluminum-based material, and contains a lubricant base oil and at least one of a phosphorus-containing carboxylic compound and a metal salt thereof (component (A)) at 0.001 to 1 mass % of the composition in terms of phosphorus. The composition may suitably be used as lubricant such as drive train lubricant for automatic or manual transmissions, grease, wet brake oil, hydraulic actuation oil, turbine oil, compressor oil, bearing oil, refrigerant oil, and the like used in apparatus having the sliding parts.

A machining installation for workpieces comprises a workpiece positioning device comprising a workpiece holder pivot unit as well as a tool positioning device comprising a tool holder pivot unit. The workpiece holder pivot unit is designed such that a workpiece holder is pivotable about at least three and no more than four workpiece holder pivot axes. Moreover, the tool holder pivot unit is designed such that a tool holder is pivotable about no more than two tool holder pivot axes. The machining installation has a simple design and ensures flexible and accurate machining of workpieces.

A combination trimming/flame treatment end effector adapted for mounting to the end of a robotic arm. A trimming blade extends from a main body portion of the end effector for performing a trimming operation. The trimming blade may be mounted in an exchangeable cartridge to facilitate blade changing. Also extending from the main body portion is a flame treatment element for performing a flame treatment operation. The flame treatment element generally comprises a torch or burner. Because both the trimming blade and the flame treatment element are part of the same end effector, the robot simply manipulates the end effector such that the desired one of the trimming blade or the flame treatment element is properly positioned for use. As such, a tooling change can be avoided. While not restricted thereto, it is contemplated that an end effector of the present invention may be used to process vehicle bumper fascias.

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.

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).

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.

The invention provides a vertical turret lathe capable of preventing an inner diameter turning tool attached to a turret tool rest from interfering with a workpiece during machining of the outer diameter of the workpiece. The vertical turret lathe comprises a work table that holds a workpiece W1 and rotates, and a working head 40 having a turret tool rest 50 and capable of moving in X-axis and Z-axis directions. A tool holder 70 for holding an inner diameter turning tool T2 via hydraulic pressure is attached to a part of the tool supporting portions 60 of the turret tool rest. The automatic tool changer apparatus 100 includes a turret-type tool magazine 120 and pistons 160 and 162, which mechanically press the pins 74 and 76 of the tool holder 70 and clamp or unclamp the tool T2.

A network component comprising at least one processor coupled to a memory and configured to exchange security information using a plurality of attributes in a management entity (ME) in an optical network unit (ONU) via an ONU management control interface (OMCI) channel, wherein the attributes provide security features for the ONU and an optical line terminal (OLT). Also included is an apparatus comprising an ONU configured to couple to an OLT and comprising an OMCI ME, wherein the OMCI ME comprises a plurality of attributes that support a plurality of security features for transmissions between the ONU and the OLT, and wherein the attributes are communicated via an OMCI channel between the ONU and the OLT and provide the security features for the ONU and the OLT.

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.

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.

Methods and systems for decoding a signal include compensating for impairments in a received signal using at least carrier phase estimation, where residual phase error remains after compensation; calculating symbol log-likelihood ratios (LLRs) for symbols in the compensated signal using Monte Carlo integration; demapping the symbols in the compensated signal using the symbol LLRs and extrinsic information from signal decoding to produce one or more estimated codewords; and decoding each estimated codeword with a decoder that generates a decoded codeword and extrinsic information.

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.

An optical communication system includes an optical-signal transmission unit transmitting an existing optical signal and a low-rate-signal superimposition unit superimposing a low-rate signal on the existing optical signal by intensity modulation. It further includes: a low-rate-signal extraction unit that extracts the low-rate signal from the existing optical signal on which the low-rate signal is superimposed and converts the extracted low-rate signal into a low-rate electric signal; an add-on optical-signal transmission unit that transmits an add-on optical signal; a low-rate-signal superimposition unit that superimposes a low-rate signal on the add-on optical signal by the intensity modulation based on the low-rate electric signal; and a repeater that repeats the add-on optical signal on which the low-rate signal is superimposed, to a transmission destination.

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.

One aspect provides an optical communication system. The system includes an optical-to-digital converter, a frequency estimator and a symbol synchronizer. The optical-to-digital converter is configured to receive an optical OFDM bit stream including an OFDM symbol bearing payload data and a symbol header preceding the OFDM payload data. The frequency estimator is configured to determine a carrier frequency offset of the payload data from the symbol header. The symbol synchronizer is configured to determine a starting location of the payload data within the bit stream by cross-correlating a synchronization pattern within the symbol header with a model synchronization pattern stored by the symbol synchronizer.

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.

A pre-emphasis control method includes calculating an average value of transmission characteristics based on transmission characteristics of a plurality of light beams received by a receiver, and determining that, among signals of the plurality of light beams, a wavelength with a deviation from the average value is a wavelength at which control is to be performed, determining that the wavelength at which control is to be performed and a wavelength adjacent thereto are a group of wavelengths at which control is to be performed, obtaining an average of transmission characteristics of the group of wavelengths at which control is to be performed, and based on a difference between averaged transmission characteristics and respective transmission characteristics of the group of wavelengths at which control is to be performed, changing a light intensity output from each transmitter that transmits a group of wavelengths at which control is to be performed.

A signal transmission device drives a light-emitting element and outputs an optical signal depending on a data signal from an electronic device. The device includes an element driving portion which supplies a driving current to the light-emitting element, wherein the driving current is obtained by superimposing a modulation current on a bias current, the modulation current being dependent on the data signal indicating emitting information of the light-emitting element. A temperature compensation portion of the device controls the bias current and the modulation current depending on the temperature so that a temperature-current characteristic of the light-emitting element is reproduced based on the voltage which is dependent on the temperature and the voltage which is independent from the temperature, thereby performing current control depending on the temperature.

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.

In one example, an optical channel monitor includes a tunable filter, a deinterleaver, first and second optical receivers, and a control module. The tunable filter is configured to receive an optical signal having a plurality of channels spaced at a nominal channel spacing. The deinterleaver has an input with an input channel spacing Fi, an even output, and an odd output, the input being connected to an output of the tunable filter. The nominal channel spacing is between about one and two times the input channel spacing Fi. A −20 dB bandwidth of the tunable filter is between about two and four times the input channel spacing Fi. The first and second optical receivers are coupled to the deinterleaver even and odd outputs, respectively. The control module is coupled to the tunable filter and is configured to tune the tunable filter to a desired center frequency.

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.

A method and system for providing joint IP/Optical Layer restoration mechanisms for the IP over Optical Layer architecture, particularly for protecting against router failure within such architecture, includes any one of plural node elements participating in the detection and restoration of the joint IP/Optical Layer architecture upon the failure of a router in one of the nodes. The plural node elements may include, but are not limited to, one of plural routers and an optical cross-connect.

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.

An apparatus and method for fault indication and localization in a Passive Optical Network (PON) comprising a multistage power splitter (100, 200, 300) with at least one 1:N splitter (120, 221, 222, 321, 322) followed by N items of 2:M splitters (131, 132, 231-233, 331-336), wherein N and M are integers greater than 1. The apparatus also comprises an Optical Time Domain Reflectometry (OTDR) device (110, 210, 310) capable of inserting an OTDR signal into the power splitter (100, 200, 300), and adapted to insert the OTDR signal between the first stage of the at least one 1:N splitter (120, 221, 222, 321, 322) and the second N items of 2:M splitters (131, 132, 231-233, 331-336).

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.

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.

An optical line termination node has a first connection arrangement for connecting a working fiber, a second connection arrangement for connecting a protection fiber, a transceiver arrangement having first primary link and a first secondary link, and protection switching means configured for being switched either in a working operating state or in a protection operating state.

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.

A laser relay module for free space optical communications including an optical telescope for receiving and transmitting optical beams; an optical diplexer for separating transmitting and received optical beams; an optical amplifier; a modulated beacon laser for line of sight control of a plurality of communicating remote network nodes; a beacon beam detector for detecting an incoming beacon optical beam for line of sight control of the optical telescope and receiving data from other network nodes; and means for inserting an output of the modulated beacon laser into the optical telescope for transmission to another network node, and for transporting the incoming beacon optical beam to the beacon detector.

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.

Intrapersonal communication systems and methods that provide an optical digital signal link between two or more local devices are disclosed. In some embodiments, the system includes a first signal converter disposed at a first end of the optical digital signal link and configured to convert between electrical digital signals from a first local device and optical digital signals from the optical digital signal link. The system can include an optical connector having a non-contact portion configured to couple optical digital signals between the first signal converter and the optical digital signal link across a gap. The system can include a second signal converter disposed at a second end of the optical digital signal link and configured to convert between electrical digital signals from the second local device and optical digital signals from the optical digital signal link.

Disclosed is a transmitter optical module which includes a first package generating an optical signal; a second package bonded with the first package by using chip-to-chip bonding, having a silicon optical circuit platform structure, and amplifying the optical signal; and an optical waveguide forming a transmission path of the optical signal from the first package to the second package.