Abstract: A fiber laser apparatus that generates invisible laser light using an amplification optical fiber having a single-mode core and outputs the invisible laser light via an output optical fiber is provided. The fiber laser apparatus includes a visible laser light source that generates visible laser light, an introducing section that introduces the visible laser light generated by the visible laser light source into a core of one of the amplification optical fiber and the output optical fiber, and a drive unit that drives, in a case of performing alignment of an irradiation position of the invisible laser light with respect to a workpiece, the visible laser light source and emits the visible laser light via the core of the output optical fiber.

Abstract: The present invention relates to an optical time domain reflectometer using, as a optical source, a polymer wavelength tunable laser which tunes the wavelength of an optical signal by using polymer grating. The optical time domain reflectometer of the present invention tunes the wavelength of a polymer wavelength tunable laser that outputs a constant optical signal and inspects cutting, reflection, and damage of an optical line by separating an optical signal returning from the optical line by an optical filter having a specific central wavelength. Since a optical source having a constant light intensity is used, the present invention has an effect of reducing the nonlinear effect generated in an optical line.

Abstract: A method and system are provided. The method includes converting, using a spatial mode converter, an input signal into a plurality of spatial modes and performing polarization multiplexing and mode multiplexing, using a polarization multiplexer and a mode multiplexer, respectively, on the input signal. The method further includes injecting the input signal into a fiber optic medium. The method additionally includes applying, using at least one spatial filter in each of a forward and a backward direction within the fiber optic medium, the plurality of spatial modes within the fiber optic medium to transmit the input signal and perform distributed fault sensing on the input signal simultaneously.

Abstract: In some examples, an optical time-domain reflectometer (OTDR) device may include a laser source to emit a plurality of laser beams. Each laser beam may include a different pulse width. A control unit may analyze, for each laser beam, a backscattered signal from a device under test (DUT). The control unit may generate, for each backscattered signal, a trace along the DUT. Further, the control unit may generate, based on an analysis of each trace along the DUT, a combined trace that identifies optical events detected along the DUT.

Abstract: A connector inspector includes a microscope assembly, a supporting tray, and a main frame. The microscope assembly is placed within the supporting tray with a bottom cylindrical protrusion inserted into a base plate of the supporting tray, and the supporting tray is coupled with the main frame with a pair of pivoting joints. The microscope assembly is horizontally biased by a spring and an adjusting knob, both set between the main frame and the microscope assembly. The microscope assembly is vertically biased by a spring and an adjusting knob, both set between the main frame and the microscope assembly. Thus, the microscope assembly is able to swing to shift the imaging axis of the microscope assembly in two dimensions using the two adjusting knobs respectively. Because the biasing means for the imaging axis are built inside the inspector, the inspector may be used with just one hand.

Abstract: A method and apparatus for automatic determination of a fiber type of at least one optical fiber span used in a link of an optical network, the method comprising the steps of measuring a length of said optical fiber span; measuring a chromatic dispersion of said optical fiber span; determining a fiber dispersion profile of said optical fiber span on the basis of the measured length and the measured fiber chromatic dispersion; and determining a fiber category and/or a specific fiber type of said optical fiber span depending on the determined fiber dispersion profile.

Abstract: In some embodiments, a distributed nondestructive inspection method for slickline cable structural defect detection transmits a light pulse along an optical waveguide in the slickline cable. A reflected light signal is 5 received from the optical waveguide in response to the light pulse. Defects can then be determined in the slickline cable based on variations in scattering intensity, phase shift, specific spectral signature, power spectral density, strain amplitude, and/or transmission loss of the reflected light signal as compared to the light pulse.

Abstract: A microscopy system that includes a first laser emitting a first laser pulse along a first beam line, the first laser pulse being a Gaussian pump beam; and a second laser emitting a second laser pulse along a second beam line, the second laser pulse being a probe beam, the Gaussian pump beam and the probe beam being delivered to a sample at right angles to each other allowing the Gaussian pump beam to shrink a focal axial diameter of the second beam line thereby enabling dipole-like backscatter stimulated emission along the second beam line.

Abstract: A system for measuring radio frequency power of an incoming radio frequency signal is described, with at least one radio frequency interface for receiving the radio frequency signal, a signal processing unit for processing the radio frequency signal, a frequency selection unit for separating at least two frequency bands of the incoming radio frequency signal, the frequency selection unit comprising several filters, at least one power detector for measuring the radio frequency power of at least one of the frequency bands processed by the at least one power detector. At least one of the several filters is connected with the at least one power detector. The frequency selection unit is configured to forward the incoming radio frequency signal to at least one of the filters wherein the frequency selection unit has at least a first operation state in which the incoming radio frequency signal is forwarded to more than one filter simultaneously or subsequently.

Abstract: An optical-fiber-characteristic-evaluating apparatus includes a measuring unit and an analyzing unit. The measuring unit measures, in one arbitrary direction, dependence F?(?) of an electric field F of a measurement-object mode, which is one of high-order spatial modes of a multimode optical fiber that is to be evaluated, upon an angle of divergence ? in a far field by performing FFS. The analyzing unit obtains dependence fr(r) of the electric field F of the measurement-object mode upon a fiber-radial-direction position r at the exit end of the multimode optical fiber by performing a calculation in accordance with a predetermined expression containing F?(?).

Abstract: A method and a system for ultimately fast frequency-scanning Brillouin optical time domain analysis are provided herein. The method may include: simultaneously launching two pairs each having a pulsed pump wave and a counter-propagating constant wave (CW) probe wave, into an optical fiber, wherein the pulsed pumps have orthogonal States of Polarization (SOPs), and wherein the two CW probe waves have a same SOP; scanning common pump-probe frequency difference, over a frequency range that encompasses a respective Brillouin Gain Spectrum (BGS) and current and expected spectral shifts of the BGS along the optical fiber; deriving, a local Brillouin Frequency Shift (BFS), in a distributed manner along the optical fiber, which is defined as the pump-probe frequency difference which maximizes the Brillouin gain on the BGS; and determining strain and/or temperature in a distributed manner along the optical fiber, based on the respective local BFS.

Abstract: By removing remaining components of Rayleigh scattered light, control is sufficiently performed of polarization states even when the wavelength of scattered light has changed. A light source unit configured to generate probe light, a wavelength control unit configured to receive backscattered light emitted from an optical fiber to be tested by the probe light and to output Brillouin backscattered light included in the backscattered light, and a self-delayed heterodyne interferometer to which the Brillouin backscattered light is input are included. The wavelength control unit includes a wavelength separation filter, a variable wavelength filter, an optical intensity measurement unit, and a control unit. The wavelength separation filter has two output ports, outputs and transmits, from one of the two output ports, the Brillouin backscattered light to the variable wavelength filter, and outputs and transmits, from the other output port, Rayleigh scattered light to the optical intensity measurement unit.

Abstract: An apparatus includes a reference fixture. The reference fixture includes a joint, and a joint tracker to track motion of the joint. The apparatus also includes a surgical instrument. A tether is connected between the joint and the surgical instrument. A shape sensor extends from the reference fixture through the joint, through the tether, and into the surgical instrument. The shape sensor is substantially free of twist. The joint tracker measures the motion of the joint. Information from the shape sensor in combination with information from the joint tracker provides absolute three-dimensional information relative to the reference fixture, i.e., provides absolute three-dimensional information in a fixed world reference frame.

Abstract: The present disclosure includes systems and methods for testing bundles of fiber optic fibers, such as fiber optic trunk cables, for correct polarity of connections at each end of the bundle of fibers while preventing the fiber optic fibers from contacting any other components during testing. The systems include a processor, a plurality of signal generators interfaced with a plurality of signal generator ports, a sensor interfaced with a sensor input port, a first selector switch, and a display, the processor operable to stimulate the plurality of signal generators one at a time in a first sequence to produce a signal, the first sequence based on a position of the first selector switch, the processor further operable to cause the display to display an output of the sensor.

Abstract: An optical signal-to-noise ratio monitor includes: a measuring unit that measures an optical signal-to-noise ratio of a polarization multiplexed optical signal, a polarization state of the polarization multiplexed optical signal changing with respect to time; a selector that selects, from a plurality of optical signal-to-noise ratios measured by the measuring unit at a plurality of measurement points within a designated measurement period, an optical signal-to-noise ratio that is higher than an average of the plurality of optical signal-to-noise ratios; and an output unit that outputs the optical signal-to-noise ratio selected by the selector.

Abstract: An electrical circuit for electric vehicle supply equipment including a pilot control signal unit structured to generate a pilot control signal having a state including one of a high state and a low state, a pilot control signal isolation unit structured to generate an isolated pilot control signal that is isolated from the power lines of the electric vehicle supply equipment and is based on the state of the pilot control signal, and an amplification unit structured to generate a pilot signal based on the state of the pilot control signal. The amplification unit is structured to receive the isolated pilot control signal and the isolated voltage and to use the isolated pilot control signal and the isolated voltage to generate the pilot signal, and the pilot signal is isolated from the power lines of the electric vehicle supply equipment.

Abstract: An OTDR device and method for characterizing one or more events in an optical fiber link are provided. A plurality of light acquisitions is performed. For each light acquisition, test light pulses are propagated in the optical fiber link and the corresponding return light signals from the optical fiber link are detected. The light acquisitions are performed under different acquisition conditions, for example using different pulsewidths or wavelengths. Parameters characterizing the event are derived using the detected return signal from at least two of the plurality of light acquisitions.

Abstract: One or more embodiments are directed to optical test instruments, such as fiber optic inspection scopes and optical power meters, for testing optical communication links, such as fiber optic connectors. The optical test instruments include a single test port that is able to operate in two modes of operation. In a first mode of operation, the optical test instrument is configured to provide an image of the endface of a fiber optic connector under test. In a second mode of operation, the optical test instrument is configured to measure power or power loss in an optical fiber under test. In that regard, the fiber optic connector only has to be coupled to a single port of an optical test instrument for a visual inspection of an endface of a fiber optic connector and a power test of the optical fiber under test.

Abstract: A method and a system are provided, in which acoustic signals received by distributed acoustic sensors are processed in order to determine the position of a source or sources of the acoustic signals. The method and system are able to determine the position of several acoustic sources simultaneously, by measuring the corresponding several acoustic signals. Furthermore, the strength of the acoustic signal or signals can be determined. The location of the acoustic source may be overlaid on a map of an area being monitored, or be used to generate an alarm if perceived to correspond to a threat or an intrusion, for example in a pipeline monitoring application. Alternatively, the method and systems can be used to monitor a hydraulic fracturing process.

Abstract: We disclose embodiments of a WDM transmitter having an in-band OTDR capability for at least a subset of the WDM channels thereof. In an example embodiment, an OTDR-enabled WDM channel of the WDM transmitter is implemented using an optical transceiver that comprises an optical transmitter and a coherent optical receiver. The optical transmitter is configured to generate a modulated optical signal by modulating a respective carrier wavelength, transmit the modulated optical signal through an optical link as a component of the corresponding WDM signal, and provide the respective carrier wavelength to the coherent optical receiver for being used therein as an optical local oscillator. The optical receiver is configured to estimate an impulse response of the optical link by coherently detecting and processing a return optical signal produced within the optical link due to distributed reflection and/or backscattering of the modulated optical signal.

Abstract: Embodiments of the present invention provide an optical fiber length measurement method and apparatus, where the method is used to measure an optical fiber length between a first device and a second device, and the method includes: acquiring, by a measurement device, timestamp parameters, where the timestamp parameters include a first transmit timestamp Ta1, a first receive timestamp Ta2, a second transmit timestamp Tb1, and a second receive timestamp Tb2; and determining, by the measurement device, the optical fiber length L according to the timestamp parameters, where when (Ta2?Tb1)+(Tb2?Ta1)?n*T, L=2.5*[(Ta2?Tb1)+(Tb2?Ta1)], or when (Ta2?Tb1)+(Tb2?Ta1)>n*T, L=2.5*[(Ta2?Tb1)+(Tb2?Ta1)?n*T]. The method does not depend on a dedicated measurement instrument such as an OTDR, an OFDR, or an OCDR, thereby simplifying a measurement process, and helping reduce a measurement cost.

Abstract: Disclosed is a method for detecting an OTDR curve tail end event to locate an optical fiber break point in an online mode, comprising following steps: 1, an OTDR emits detection light to an optical fiber operation link, and receives reflection light to form reflection sampling point data containing tail end event; 2, head end reflection point in sampling point is found out; 3, traversal is carried out to find search region end point; 4, segmented line fitting is carried out in region of [search region end point, head end reflection point] in reversed direction, start point of section of line meeting predetermined condition is used as a search region start point; 5, if absolute value of difference between largest sampling value in search region and sampling value of search region start point is larger than second preset threshold value, tail end event is judged as reflection tail end event.

Abstract: The present embodiment relates to a method of directly measuring a leakage loss from a peripheral core in a MCF with a coating to the coating. In the measurement method, in a high refractive-index state in which the coating is present on an outer periphery of a common cladding, first transmission power of measurement light, which propagates through the peripheral core of the MCF, is measured. On the other hand, in a low refractive-index state in which a low-refractive-index layer with a lower refractive index than the common cladding is provided on the outer periphery of the common cladding, second transmission power of the measurement light, which propagates through the peripheral core of the MCF, is measured. The leakage loss LL from the peripheral core to the coating is calculated as a difference between the first transmission power and the second transmission power.

Abstract: An apparatus is configured to detect a predetermined physical amount and relay communication between a network and a terminal. The apparatus calculates a communication disabling risk based on the predetermined physical amount, and notifies another apparatus of takeover of a process of relaying the communication between the network and the terminal when the communication disabling risk is equal to or greater than a predetermined threshold.

Abstract: An intrusion detection system includes a suspended optical fiber having a neutral buoyancy and an optical time-domain reflectometer connected to the suspended optical fiber at an origin location. The suspended optical fiber is connected to a mooring at a first end of the suspended optical fiber and further includes at least one terminal end. The optical time-domain reflectometer includes a light source operable to emit an optical pulse of light into the suspended optical fiber from the origin location toward the terminal end, and a processor operable to receive an optical return signal from the terminal end of the suspended optical fiber or from a deformation created by a disturbance to the suspended optical fiber and to determine a location and a type of the disturbance based on an analysis of at least a time to receive the optical return signal and a magnitude of the optical return signal.

Abstract: Apparatus and methods for analyzing single molecule and performing nucleic acid sequencing. An apparatus can include an assay chip that includes multiple pixels with sample wells configured to receive a sample, which, when excited, emits emission energy; at least one element for directing the emission energy in a particular direction; and a light path along which the emission energy travels from the sample well toward a sensor. The apparatus also includes an instrument that interfaces with the assay chip. The instrument includes an excitation light source for exciting the sample in each sample well; a plurality of sensors corresponding the sample wells. Each sensor may detect emission energy from a sample in a respective sample well. The instrument includes at least one optical element that directs the emission energy from each sample well towards a respective sensor of the plurality of sensors.

Abstract: An optical signal quality monitoring apparatus includes: a holding unit configured to hold a relational expression representing a relationship among an optical signal intensity, a noise intensity, and an optical signal-to-noise ratio and a plurality of calibration coefficients used in the relational expression; a measurement unit configured to measure an optical power of input light and a noise power in the input light; an arithmetic unit configured to calculate a plurality of optical signal-to-noise ratios, based on the optical power and the noise power measured by the measurement unit, by using the relational expression and the plurality of calibration coefficients; and a determination unit configured to select one optical signal-to-noise ratio from the plurality of optical signal-to-noise ratios, based on a magnitude relationship of the plurality of optical signal-to-noise ratios calculated by the arithmetic unit.

Abstract: A wireless power transmission system includes a power control device, a power transmitting device, a relay device, and a power receiving device. The power control device includes a direct-current power supply, and a main control circuit that generates a first load instruction value and a second load instruction value. The power transmitting device returns a first response signal and information on alternating-current power supplied to a load circuit in the relay device, such as a voltage value, when receiving the first load instruction value. The load circuit returns a second response signal when receiving the second load instruction value. The main control circuit determines that not the load circuit but the relay-side power receiving circuit is faulty when not receiving the second response signal within a first period and receiving the first response signal within a second period and not receiving is the information within a second period.

Abstract: A method of stimulated Brillouin scattering is proposed in which both slopes of the BGS spectrum are probed to achieve immunity to pump power variations. Suitably applied, the technique can maintain all the benefits of the known Slope-Assisted-BOTDA technique, while using the same setup but at the cost of halving the sampling speed. the method may include: obtaining a reference Brillouin gain spectrum (BGS) representative of steady state or average conditions in various locations of the optical fiber along its length; generating, based on the reference BGS, a probe wave being a complex waveform comprising a first and second set of waveforms, each set having waveforms tailored to match an opposite slope of the reference BGS, at the various locations; performing stimulated Brillouin scattering at the various locations by applying a pump pulse wave to the probe wave; and deducing the local Brillouin frequency shift (BFS) at the various locations.

Abstract: The device includes a first detector configured to detect, from received signal power, first fault parameters related to an occurrence of a first fault on this optical fiber. The device further includes a database configured to store the first fault parameters and a second detector configured to detect from the received signal power second fault parameters related to a restoration of a second fault on the optical fiber. The device further includes a comparator configured to compare the second fault parameters with the stored fault parameters and to decide that the fault is resolved if the first fault parameters most closely match the second fault parameters.

Abstract: A fiber optic connector inspection display system including: a input unit which receives fiber end-face images; a display mode selection unit which allows a user to select at least one of an image capture mode or an image review mode; a capturing unit which captures the fiber end-face images; a storing unit which stores the captured images as a first still image and a second still image; a display unit which displays the received fiber end-face images from the input unit or the stored first and second still images, and a control unit which stores each of the first and second still images with a user defined identification label, and the control unit may further label the each of the first and second still images with a preset image pair mode label if the user selects a preset image pair mode.

Abstract: The invention concerns a method of characterizing a multimode optical fiber link comprising a light source and a multimode fiber, which comprises: a step (170) of characterizing the multimode fiber using a measurement of the Dispersion Modal Delay (DMD) and delivering fiber characteristic data; a step (171) of characterizing the light source by at least three source characteristic curves showing three parameters of the source as a function of a fiber radius r and obtained by a technique similar to the DMD measurement; a step (173) of computing an Effective Bandwidth (EB) of the link, comprising calculating (172) a transfer function using both the fiber characteristic data and each of said source characteristic curves.

Abstract: Provided is a linear automatic protection switching (APS) apparatus and method that minimizes a data loss in an optical transport network (OTN) system, the apparatus and method that may maintain time synchronization by transmitting/receiving time synchronization signals between APS apparatuses of a working path and a redundant path, and transmitting/receiving time synchronization signals between local and remote APS apparatuses.

Abstract: The present disclosure relates to a image data generating method and device. The device may be configured to obtain a plurality of frames of images of a scene including at least one object, each of the plurality of frames of images is associated with a character distance of a plurality of character distances of the electronic device. For each of the plurality of frames of images, device may determine a target image area, wherein the target image area is an image area on which an object in the scene is sharply focused; and set a focus area in the target image area. Finally, the device may generate an all-focused image by combining the plurality of frames of images, wherein each of the at least one object is sharply focused.

Abstract: A dual wavelength Optical Time Domain Reflectometer (OTDR) system, embedded in a network element, includes a first OTDR source for wavelength ?1; a second OTDR source for wavelength ?2; an OTDR measurement subsystem adapted to measure backscatter signals ?1_BACK, ?2_BACK associated with the wavelength ?1 and the wavelength ?2; and one or more ports connecting the first OTDR source, the second OTDR source, and the OTDR measurement subsystem to one or more fiber pairs; wherein wavelength ?1 and wavelength ?2 are each outside of one or more signal bands with traffic-bearing channels, thereby enabling operation in-service with the traffic-bearing channels.

Abstract: Various embodiments include apparatus and methods structured to interrogate a plurality of sensor assemblies, where each sensor assembly may have one or more transmissive optical sensors. The plurality of sensor assemblies can be arranged to couple between two optical fibers. The interrogation can include generating optical signals to each sensor assembly such that each sensor assembly can be selectively and individually interrogated using semiconductor optical amplifiers. Additional apparatus, systems, and methods are disclosed.

Abstract: The invention relates to a metamaterial nano-sensing system, and in particular to a high-sensitivity metamaterial nano-sensing system with an ultra-narrow line width spectral response. The system includes an input light path, a metamaterial nano-sensing unit and an output light path which are sequentially provided along a direction of a light path, and the metamaterial nano-sensing unit includes a Bragg grating and a metallic periodic array arranged above the Bragg grating. The nano-sensing system provided by the invention has an ultra-narrow line width spectral response, so that sensitivity of a nanosensor is effectively improved, and broad application prospect in the fields of portable biosensing, drug development and detection, environment monitoring and the like is ensured.

Abstract: Light output from a light source is distributed to intensity modulators that are associated with different spatial modes and that have different modulation conditions. An operation for receiving modulated light from each of the intensity modulators is performed for SDM fibers of different lengths while the light source is in operation, and pieces of optical power information are determined for respective spatial modes to be measured, from difference information regarding the lengths and the received optical powers.

Abstract: A method is provided for determining an optical signal to noise ratio of a dual polarization optical signal. The method includes: detecting, in the dual polarization optical signal, a modulation signal which modulates, at at least one low amplitude level that is approximately zero and at a high amplitude level, the dual polarization optical signal, and determining the optical signal to noise ratio from a measurement of the power of the modulation signal.

Abstract: An excitation light source device includes: an excitation light source to generate the Raman excitation light; a light source controller to control an intensity of the Raman excitation light; an amplified spontaneous emission noise measurer to measure an intensity of amplified spontaneous emission noise caused by the Raman excitation light; and a transmission line abnormality analyzer to detect abnormality in the transmission line on a basis of a control state of the light source controller and a measurement result of the amplified spontaneous emission noise measurer. In a state where the abnormality is not detected, the light source controller controls the intensity of the Raman excitation light to gradually increase to a set value. In a state where the abnormality is detected, the light source controller controls the excitation light source to stop or reduce generation of the Raman excitation light.

Abstract: A polarization-related characteristic of an optical path is determined from a predetermined function of the mean-square of a plurality of differences between polarization-analyzed optical power parameters corresponding to pairs of wavelengths mutually spaced about a midpoint wavelength by a small optical frequency difference. At least some of the said differences correspond to wavelength pairs measured under conditions where at least one of midpoint wavelength, input state of polarization (I-SOP) or analyzed state of polarization (A-SOP) of a pair is different.

Abstract: The disclosed technology in this patent document includes, among others, methods and apparatus for distributed measuring at least one of fiber bend or stress related characteristics along an optical path of a fiber under test (FUT) using both a light input unit and a light output unit connected to the FUT at one single end.

Abstract: Apparatus for measuring the distribution of strain and temperature along an optical fibre (34) by analysing the distribution of the Rayleigh scattering and stimulated Brillouin scattering wavelength shifts along the length of a sensing fibre (34) using a Wavelength-Scanning Optical Frequency-Domain Analysis (WS-BOFDA) technique in which a wavelength-swept laser (12) sources a Brillouin “pump” radiation and excites a Brillouin ring laser (14) that sources a Brillouin “stimulus” radiation with wavelength shifted with respect to the excitation of a tuneable quantity. One optical Mach Zehnder or Michelson interferometer (27) is excited by the “stimulus” radiation on both the measurement arm, that comprises the sensing fibre (34), and the reference arm (38) while the “pump” radiation is injected only in the measurement arm by a controllable inhibition system (57).

Abstract: A distributed gas detection system includes one or more hollow core fibers disposed in different locations, one or more solid core fibers optically coupled with the one or more hollow core fibers and configured to receive light of one or more wavelengths from a light source, and an interrogator device configured to receive at least some of the light propagating through the one or more solid core fibers and the one or more hollow core fibers. The interrogator device is configured to identify a location of a presence of a gas-of-interest by examining absorption of at least one of the wavelengths of the light at least one of the hollow core fibers.

Abstract: An optical shape sensing system and method with at least two optical fibers (OSF1, OSF2) both comprising optical shape sensing elements. A processor (P) is arranged to register a coordinate system indicative of a position of one of the optical fibers (OSF1) in space, and to register a position (R2) of the other optical fiber (OSF2) in relation to this coordinate system. An optical console system (C, C1, C2) serves to interrogate the optical shape sensing elements in both optical fibers (OSF1, OSF2), and to accordingly determine a measure of a three-dimensional shape (I) of both optical fibers (OSF1, OSF2), based on the registered position (R2) of the second optical fiber (OSF2) in relation to the coordinate system. This provide the possibility of providing 3D optical shape sensing of the length of both optical fibers (OSF1, OSF2), thus allowing 3D shape reconstruction of e.g. long medical devices with lengths of several meters. More than two shape sensing optical fibers, e.g.

Abstract: Brillouin optical distributed sensing device and method is provided and includes a structure for generating an optical pulsed signal and an optical probe signal. The structure includes a circulation component for directing the optical pulsed signal to a sensing optical fiber, and directing an optical measurement signal with Brillouin scattering information arising from the sensing optical fiber toward a detection apparatus.

Abstract: System and method of distributed sensing based on Brillouin stimulated scattering on optical fiber (3), consisting of separating the two signals of which the probe signal is composed and obtaining the difference between the stimulated amplification band (8) and the attenuation band (9), or vice-versa. In this way a signal is obtained with greater amplitude than in the case of detection being performed with a single band. Thus the signal-to-noise ratio is improved in the sensor signal, dynamic range and the range is increased and the uncertainty of the measurement is decreased. It also eliminates the common noise present in the two bands of the probe signal and, in the case of using a balanced detector in detection, it improves the saturation characteristics of the detector, being able to achieve much larger signal amplitudes than in the conventional case.

Abstract: Raman amplifier systems and methods with an integrated Optical Time Domain Reflectometer (OTDR) for integrated testing functionality include an amplifier system, an OTDR and telemetry subsystem, and a method of operation. The OTDR and telemetry subsystem is configured to operate in an OTDR mode when coupled to a line in port and to operate in a telemetry mode when coupled to a line out port. The OTDR and telemetry subsystem enables on-demand fiber testing while also operating as a telemetry channel that is both a redundant optical service channel (OSC) and provides a mechanism to monitor Raman gain over time. The OTDR and telemetry subsystem minimizes cost and space by sharing major optical and electrical components between the integrated OTDR and other functions on the Raman amplifier.

Abstract: There are proposed an optical fiber property measuring device and an optical fiber property measuring method which can enhance spatial resolution more than before. In the present invention, in synchronization with frequency modulation applied to x-polarized light, intensity modulation is also applied to the x-polarized light by an intensity modulation means. This makes it possible to increase or decrease the intensity of the x-polarized light at a specific frequency, thereby allowing the effective length of a Brillouin dynamic grating formed by the x-polarized light to be adjusted. As a result, the shape of the reflection spectrum obtained when y-polarized light is reflecting by the Brillouin dynamic grating can also be adjusted optimally, which leads to enhancement of spatial resolution with the y-polarized light.

Abstract: Methods and systems for sensing conditions of a fiber include splitting a light signal into two branches. A first branch is converted to have a mode different from that of the second branch. Both branches are mode multiplexed into a single fiber. An output of the fiber is mode demultiplexed into the two branches. The first branch is mode converted to its original mode. Brillouin scattering patterns of the two branches are compared to determine a temperature and strain profile of the fiber.