pti

Prefetch optimizer measuring execution time of instruction sequence cycling through each selectable hardware prefetch depth and cycling through disabling each software prefetch instruction of an instruction sequence of interest

A prefetch optimizer tool for an information handling system (IHS) may improve effective memory access time by controlling both hardware prefetch operations and software prefetch operations. The prefetch optimizer tool selectively disables prefetch instructions in an instruction sequence of interest within an application. The tool measures execution times of the instruction sequence of interest when different prefetch instructions are disabled. The tool may hold hardware prefetch depth constant while cycling through disabling different prefetch instructions and taking corresponding execution time measurements. Alternatively, for each disabled prefetch instruction in the instruction sequence of interest, the tool may cycle through different hardware prefetch depths and take corresponding execution time measurements at each hardware prefetch depth. The tool selects a combination of hardware prefetch depth and prefetch instruction disablement that may improve the execution time in comparison with a baseline execution time.




pti

Polycyclic organic compound, optically anisotropic film and method of production thereof

The polycyclic organic compounds which are substantially transparent for an electromagnetic radiation in the visible spectral range, an anisotropic optical film comprising at least one polycyclic organic compound and a method of producing thereof are disclosed. The polycyclic organic compounds have a general formula (I) wherein A and B are acid groups, n is the number of phenyl rings in the range from 3 to 10; m is 0, 1, 2 or 3; l is 1, 2, or 3, p is 1, 2, 3, 4, 5 or 6, C is a counterion from a list comprising H+, NH+4, Na+, K+, Li+, Cs+, Ca2+, Mg2+, Sr2+, La3+, Zn2+, Zr4+, Ce3+, Y3+, Yb3+, Gd3+, and any combination thereof; k is the number of counterions necessary for compensation of the negative electric charge equal to (−p).




pti

Multiple volume encryption of storage devices using self encrypting drive (SED)

A method for encrypting data on a disk drive using self encrypting drive is provided. The method includes encryption of data chunks of a computing device. The method further includes associating the encrypted data chunks with encryption key indexes of the computing device. Moreover, the method further includes receiving the encryption key indexes for given logical block addresses of the data chunks. The method further includes determining the encryption keys to be used to encrypt the data chunks based on the encryption key indexes of the data chunks to the disk drive.




pti

Identification and management of unsafe optimizations

Techniques for implementing identification and management of unsafe optimizations are disclosed. A method of the disclosure includes receiving, by a managed runtime environment (MRE) executed by a processing device, a notice of misprediction of optimized code, the misprediction occurring during a runtime of the optimized code, determining, by the MRE, whether a local misprediction counter (LMC) associated with a code region of the optimized code causing the misprediction exceeds a local misprediction threshold (LMT) value, and when the LMC exceeds the LMT value, compiling, by the MRE, native code of the optimized code to generate a new version of the optimized code, wherein the code region in the new version of the optimized code is not optimized.




pti

Contactless authentication of optical disk drives

An optical disc drive (ODD) includes a radio-frequency identification (RFID) reader. The reader includes a circuit and a coil antenna which has a rotational symmetry with respect to a rotation axis of a motor, shaft and turntable of the ODD. The coil antenna can be secured to a wall of a housing of the ODD or around the motor and/or shaft. The reader can read an RFID tag on an optical disc. The RFID tag includes a circuit and a coil antenna which has a rotational symmetry with respect to the disc. As a result, the RFID tag can be read while the disc is rotating. A magnetic insulating material such as a ferrite polymer composite film is used to magnetically insulate the coil antenna. An authentication code can be read from the RFID tag to control access to content of the optical disc.




pti

Techniques to transmit commands to a target device to reduce power consumption

Techniques are described to transmit commands to a display device. The commands can be transmitted in header byte fields of secondary data packets. The commands can be used to cause a target device to capture a frame, enter or exit self refresh mode, or reduce power use of a connection. In addition, a request to exit main link standby mode can cause the target enter training mode without explicit command to exit main link standby mode.




pti

Method of labeling sulfenic acid-containing proteins and peptides

A method of labeling a sulfenic acid (—SOH) group of a cysteine residue in a protein; or peptide, comprises contacting said protein or peptide with a beta-ketoester to covalently couple said beta-ketoester to said cysteine residue and form a beta-ketoester-labeled cysteine residue in said protein or peptide.




pti

Compound for use in peptide synthesis

The present invention generally relates to processes and methods of peptide and protein synthesis. The present invention also relates to specific compounds for use in such processes and methods. It is shown herein that peptides with a C-terminal tertiary N,N-bis(2-mercaptoethyl)-amide (BMEA) undergo N-to-S acyl transfer at weakly acidic pH to form a transient thioester which can be captured for direct ligation with a cysteinyl peptide. These C-terminal BMEA peptides are easily prepared with standard Fmoc solid-phase synthesis protocols, thus giving a very convenient access to the thioester components for native chemical ligation.




pti

Bismuth-thiols as antiseptics for biomedical uses, including treatment of bacterial biofilms and other uses

Compositions and methods, including novel homogeneous microparticulate suspensions, are described for treating natural surfaces that contain bacterial biofilm, including unexpected synergy or enhancing effects between bismuth-thiol (BT) compounds and certain antibiotics, to provide formulations including antiseptic formulations. Previously unpredicted antibacterial properties and anti-biofilm properties of disclosed BT compounds and BT compound-plus-antibiotic combinations are also described, including preferential efficacies of certain such compositions for treating certain gram-positive bacterial infections, and distinct preferential efficacies of certain such compositions for treating certain gram-negative bacterial infections.




pti

Estimating virtual machine energy consumption

A method and apparatus for estimating virtual machine energy consumption, and in particular, a method and apparatus for estimating virtual machine energy consumption in a computer system. The method includes: obtaining system energy consumption of the system hardware resources; obtaining event information of a plurality of functional units into which the system hardware resources are divided, and mapping the event information to the respective virtual machines; and calculating energy consumption of the virtual machines according to a plurality of energy consumption coefficients corresponding to the plurality of functional units and according to the event information mapped to the functional units of the respective virtual machines.




pti

Reducing power consumption during manufacturing test of an integrated circuit

Aspects of the invention provide for reducing power consumption during manufacturing testing of an IC. In one embodiment, aspects of the invention include a method for reducing power consumption during a manufacturing test of an integrated circuit (IC), the method including: providing a plurality of domains, each domain associated with a clock phase; grouping, based on each domain, a first plurality of scan chains into a first test group; grouping, based on each domain, a second plurality of scan chains into a second test group, wherein the grouping of the first test group and of the second test group includes determining which domains can be tested simultaneously; and performing the manufacturing test of the IC.




pti

Method and apparatus for adaptive display calibration

A calibration system may be provided for calibrating displays in electronic devices during manufacturing. The calibration system may include calibration computing equipment and a test chamber having a light sensor. The calibration computing equipment may be configured to operate the light sensor and the display to gather display performance data. The calibration computing equipment may extract display performance statistics from the display performance data and adaptively select and perform display calibration sequences using the display performance statistics. The calibration computing equipment may be configured to determine whether or not to perform display calibration and whether or not to gather additional display performance data based on display performance statistics extracted during a preceding display calibration sequence. The calibration computing equipment may be configured to iteratively and adaptively perform display calibration sequences until a display is successfully calibrated.




pti

Pressure-sensitive adhesive for polarizing plates, pressure-sensitive adhesive sheet, polarizing plate with pressure-sensitive adhesive and production process for the same and optical film and production process for the same

Provided is a pressure-sensitive adhesive for polarizing plates which can adhere a polarizing plate on a liquid crystal cell with good adhesion durability and has the characteristic that a liquid crystal display device obtained therefrom is less liable to cause light leakage even under the environment of high temperature and high humidity and which makes it possible remove the polarizing plate. The pressure-sensitive adhesive for polarizing plates is prepared by irradiating a pressure-sensitive adhesive material comprising (A) an acrylic base polymer having a weight average molecular weight of 1,000,000 or more comprising a monomer having a hydroxyl group in a monomer composition ratio of 10 mass % or less, (B) an acrylic base polymer having a weight average molecular weight of 1,000,000 or more comprising a monomer having a carboxyl group in a monomer composition ratio of 10 mass % or less and (C) an active energy beam-curable compound with an active energy beam, wherein a mass ratio of the component (A) to the component (B) is 100:1 to 100:50, and a storage elastic modulus (G') at 23° C. is 0.3 MPa or more.




pti

Magnetic-core polymer-shell nanocomposites with tunable magneto-optical and/or optical properties

Methods are disclosed for synthesizing nanocomposite materials including ferromagnetic nanoparticles with polymer shells formed by controlled surface polymerization. The polymer shells prevent the nanoparticles from forming agglomerates and preserve the size dispersion of the nanoparticles. The nanocomposite particles can be further networked in suitable polymer hosts to tune mechanical, optical, and thermal properties of the final composite polymer system. An exemplary method includes forming a polymer shell on a nanoparticle surface by adding molecules of at least one monomer and optionally of at least one tethering agent to the nanoparticles, and then exposing to electromagnetic radiation at a wavelength selected to induce bonding between the nanoparticle and the molecules, to form a polymer shell bonded to the particle and optionally to a polymer host matrix. The nanocomposite materials can be used in various magneto-optic applications.




pti

Acrylic resin composition, method of manufacturing the same, and architectural material, fashion accessory, and optical material formed using the same

The present invention provides an acrylic resin composition containing a polycrystal of colloidal particles of silicon oxide in an acrylic resin that is formed by curing an acrylic monomer liquid at room temperature and/or an acrylic oligomer liquid at room temperature, wherein a mean distance between the colloidal particles in the polycrystal is 140 to 330 nm. The size of the single crystal that constitutes the polycrystal can be controlled by adjusting the content of silicon oxide and/or the additive amount of impurities. An architectural material, a fashion accessory, and an optical material are provided that are formed by using the acrylic resin composition.




pti

Method for optimizing spin time in a centrifuge apparatus for biologic fluid

A method for controlling a centrifuge blood component separation system for separating components of a blood product, the separation system comprising a centrifuge and a separation bag and at least one transfer bag. The method comprises selecting a nominal hematocrit value such that an actual hematocrit value is expected to be less than said nominal hematocrit; centrifuging a separation bag containing a volume of composite liquid so as to cause the sedimentation of at least a first component and a second component; transferring some of the first component to a first transfer bag; detecting time of passage of a red blood cell interface at a pre-selected location in the separation bag; and adjusting a predicted processing time based on the time of passage of the red blood cell interface.




pti

Method for optimizing the operation of a hydrocarbon synthesis unit starting from synthesis gas, by controlling the partial pressure of CO

A method is described for optimizing the operation of a reaction section for the synthesis of hydrocarbons from a feed comprising synthesis gas, operated in the presence of a catalyst comprising cobalt, said method comprising the following steps: a) determining the theoretical partial pressure of CO in the reaction section;b) optionally, adjusting the partial pressure of CO determined in step a) to a value of 4 bar or higher;c) determining a new value for the theoretical partial pressure of CO in the reaction section.




pti

Adaptive multiple shooting optimization method for determining optimal spacecraft trajectories

Disclosed herein is a method for determining a trajectory for a transfer of a spacecraft from a starting space body to a target space body with respect to a given central space body, wherein the determined trajectory is optimal with respect to a given space mission requirement to be met by the transfer of the spacecraft. The method comprises providing, according to the Pontryagin maximum principle, a physical-mathematical model relating model quantities and physical quantities representing the transfer of the spacecraft with respect to the given central space body.




pti

Systems and methods for subsurface oil recovery optimization

Systems and methods for subsurface secondary and/or tertiary oil recovery optimization based on either a short term, medium term or long term optimization analysis of selected zones, wells, patterns/clusters and/or fields.




pti

Depositing polymer solutions to form optical devices

Provided are methods of depositing polymer solutions on substrates to form various optical elements. A polymer solution may include about 0.1%-30% by weight of a specific polymer having rigid rod-like molecules. The molecules may include various cores, spacers, and sides groups to ensure their solubility, viscosity, and cross-linking ability. The deposition techniques may include slot die, spray, molding, roll coating, and so forth. Pre-deposition techniques may be used to improve wettability and adhesion of substrates. Post-deposition techniques may include ultraviolet cross-linking, specific drying techniques, evaporation of solvent, treating with salt solutions, and shaping. The disclosed polymers and deposition processes may yield optical elements with high refractive index values, such as greater than 1.6. These optical elements may be used as +A plates, −C plates, or biaxial polymers and used as retarders in LCD active panels or as light collimators and light guides.




pti

Algorithm for the automatic determination of optimal AV and VV intervals

Methods and devices for determining optimal Atrial to Ventricular (AV) pacing intervals and Ventricular to Ventricular (VV) delay intervals in order to optimize cardiac output. Impedance, preferably sub-threshold impedance, is measured across the heart at selected cardiac cycle times as a measure of chamber expansion or contraction. One embodiment measures impedance over a long AV interval to obtain the minimum impedance, indicative of maximum ventricular expansion, in order to set the AV interval. Another embodiment measures impedance change over a cycle and varies the AV pace interval in a binary search to converge on the AV interval causing maximum impedance change indicative of maximum ventricular output. Another method varies the right ventricle to left ventricle (VV) interval to converge on an impedance maximum indicative of minimum cardiac volume at end systole. Another embodiment varies the VV interval to maximize impedance change.




pti

Hot surface igniter adaptive control method

An adaptive gaseous fuel ignition control method for use in consumer and commercial appliances that reduces stress on and increases the life of a hot surface igniter without resulting in a failure to ignite condition is provided. The method provides a preheating period, a full temperature period, and a trial for ignition period. The preheating period gradually increases the power applied to reduce the stress resulting therefrom. Once a gas valve has been commanded open, the controller monitors the time for ignition of the gaseous fuel. If the time is longer than a threshold, either the applied power or the period of time during which the power is applied is increased to shorten the time. If, however, the ignition period is shorter than the threshold, either the power applied or the period of time during which the power is applied before commanding the gas valve open is lowered or shortened.




pti

Resin composition for forming optical waveguide and optical waveguide using the composition

A resin composition for forming an optical waveguide brings together excellent bending resistance, a low refractive index, and low tackiness suitable for a roll-to-roll (R-to-R) process as a material for forming an optical waveguide, in particular, a material for forming a clad layer. The resin composition for forming an optical waveguide to be used in formation of an optical waveguide includes a polyvinyl acetal compound having a structural unit represented by the following general formula (1) as a main component: in the formula (1), R represents an alkyl group having 1 to 3 carbon atoms, and k, m, and n represent ratios of respective repeating units in a main chain and each represent an integer of 1 or more.




pti

Optimization of waveform operation in electronic musical instrument

An electronic musical instrument having a number of keys, having tone generators capable of simultaneous tone production, the tone generators being smaller in number than the number of keys. The instrument forms an operation for synthesizing a desired waveform, the operation for synthesizing a desired waveform being performed in a repeating cyclic order with an operation cycle and in which the waveform is transferred to the tone generators and read out therefrom at a rate in accordance with the note of a key being depressed to obtain a desired musical waveform. The device includes a number-of-depressed keys detecting device which counts the number of keys which are actuating the tone generator upon depression. A cycle altering device is provided for changing the operation cycle, as a whole, on the basis of the number of depressed keys, counted by the number-of-depressed keys detecting device. The construction allows for a waveform of a smooth temporal variation to be produced.




pti

Uplink interference mitigation by adapting open cell transmission power

Methods and apparatus are disclosed for interference mitigation of an open-access node. The method includes determining, at the open-access node, whether uplink interference from a mobile entity is above a threshold. The method includes adjusting a transmission power to trigger a hand-in of the mobile entity in response to determining the uplink interference is above the threshold. The method includes handing-in the mobile entity from a first cell in response to adjusting the transmission power. The method includes redirecting the mobile entity to a second cell different from the first cell.




pti

Coordinated multipoint transmission and reception (CoMP)

A communications method implemented in a transmission point (TP) used in a coordinated multipoint transmission and reception (CoMP) system is disclosed. The communications method comprises transmitting, to a user equipment (UE), attributers for up to four indicators indicating at least physical downlink shared channel (PDSCH) resource element (RE) mapping, and transmitting, to the UE, one of the four indicators, each of which is conveyed in 2 bits, wherein the four indicators comprises ‘00’, ‘01’, ‘10’, and ‘11’ corresponding to a first set, a second set, a third set, and a fourth set of parameters, respectively. Other methods, apparatuses, and systems are also disclosed.




pti

Intercepting voice over IP communications and other data communications

Methods and apparatus for intercepting communications in an Internet Protocol (IP) network involve maintaining dialing profiles for respective subscribers to the IP network, each dialing profile including a username associated with the corresponding subscriber, and associating intercept information with the dialing profile of a subscriber whose communications are to be monitored. Intercept information will include determination information for determining whether to intercept a communication involving the subscriber, and destination information identifying a device to which intercepted communications involving the subscriber are to be sent. When the determination information meets intercept criteria communications are established with a media relay through which communications involving the subscriber will be conducted or are being conducted to cause the media relay to send a copy of the communications involving the subscriber to a mediation device specified by the destination information.




pti

Reception apparatus, reception method, and reception program

A reception apparatus is configured to receive data including a plurality of packets each of which has information on a time point when the packet is generated; to extract a terminal packet which is a packet included in the data received and which has information on a time point which is nearest to a current time point; and to control an operation clock by comparing the information on the time point included in the terminal packet with information on an elapsed time obtained by adding information on a time point, which is included in a terminal packet of preceding data, to an elapsed time from when the preceding data is received to the current time point.




pti

Nonhuman mammal whose mtDNA is from a nonhuman mammal resistant to a selected disease or disorder and whose nDNA is from a nonhuman donor mammal more susceptible to the selected disease or disorder

Provided herein are mitochondrial-nuclear exchanged cells and animals comprising mitochondrial DNA (mtDNA) from one subject and nuclear DNA (nDNA) from a different subject. Methods for producing a mitochondrial-nuclear exchanged animal and animals made by the methods are provided. Also provided are methods of screening for agents useful for treating a disease or disorder using mitochondrial-nuclear exchanged animals or cells, tissues or organs thereof.




pti

Dinitroxide-type biradical compounds optimized for dynamic nuclear polarization (DNP)

The present invention relates to the field of organic chemistry and in particular to organic free radicals used as polarizing agents in the technique of Dynamic Nuclear Polarization (DNP), which involves transferring the polarization of electron spins to the nuclei of a compound whose Nuclear Magnetic Resonance (NMR) is being observed. It concerns Dinitroxide-type Biradical polarizing agents characterized by a rigid linkage between the aminoxyl groups of said nitroxide units. This particular structure enables, at low temperatures and high fields, optimal transfer of polarization and optimal enhancement of NMR/MAS signals of the polarized nuclei of the compound studied.




pti

Process for preparing a compound useful for producing an optically active diazabicyclooctane compound

A process for preparing the compound of the following formula (E): wherein Bn represents a benzyl group, and tBu represents a tert-butyl group, the process including: (a) subjecting the following compound (B) to trifluoroacetylation, wherein tBu represents a tert-butyl group to produce the following compound (C): wherein tBu represents a tert-butyl group, and TFA represents a trifluoroacetyl group; (b) reacting the compound (C) with benzyloxyamine in the presence of a hydroxyl group activating agent to produce the following compound (D): wherein Bn represents a benzyl group, tBu represents a tert-butyl group, and TFA represents a trifluoroacetyl group; and (c) subjecting the compound (D) to detrifluoroacetylation.




pti

Fiber optic connector fiber stub remover and method

A fiber optic connector fiber stub remover and method for automated fiber stub removal. The device has a top plate with a platen opening, and a platen with a well that carries a polishing film over the well. An air pocket is formed between the polishing film and the well. The platen is positioned with a top surface of the polishing film accessible via the platen opening. A fixture holds connector ends of fiber optic cables with fiber stubs extending therefrom, and a weight biases the fiber stubs into contact with the polishing film. A motor is controlled by a motor control unit to control a ramp up time and final speed of movement of the platen over a timespan. Each connector ends moves independently relative to the polishing film. The air pocket provides shock absorption of the polishing film so that an ideal pressure is exerted on each fiber stub during stub removal.




pti

Trim and flame robot end effector with optional automatic blade change feature

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.




pti

Optical network terminal management control interface-based passive optical network security enhancement

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.




pti

Method and system for detecting fiber fault in passive optical network

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.




pti

Method and apparatus for transporting deterministic traffic in a gigabit passive optical network

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.




pti

Optical transceiver having an OTDR mode, and a method of obtaining test data for testing an optical fiber

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.




pti

LDPC-coded modulation for ultra-high-speed optical transport in the presence of phase noise

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.




pti

Method and apparatus for dynamically allocating bandwidth to a client in a passive optical network

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.




pti

Method of optical interconnection of data-processing cores on a chip

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.




pti

Optical communication system

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.




pti

Frame/symbol synchronization in coherent optical OFDM

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.




pti

Pre-emphasis control method and optical transmission system

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.




pti

Optical receiver, polarization separation device and polarization separating method

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.




pti

Optical channel monitor

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.




pti

Optical transceiver having enhanced EMI tolerance

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.




pti

Photonic monitoring for optical signals

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.




pti

Joint IP/optical layer restoration after a router failure

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.




pti

Optical transceiver having enhanced EMI tolerance

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.




pti

Method and apparatus for fault discovery in a passive optical network (PON)

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).