Abstract: A monitoring system for monitoring a plurality of fibre Bragg gratings in an optical fibre, each fibre Bragg grating being sensitive to a different wavelength of light. The system comprises a broadband source for illuminating the optical fibre; at least one optical interferometer; light feeding means for feeding to an input of the interferometer light reflected from the fibre Bragg gratings, and a processor for processing the output from the interferometer to determine the wavelength of the reflected light. The light feeding means comprise a wavelength division multiplexer operable to separate light received from the optical fibre into a plurality of wavelengths, each associated with one of the fibre Bragg gratings and/or a time division mulitplexer operable to separate light received from the optical fibre into in a time separated series.

Abstract: A fault detector for fiber optic cabling is provided in a hand held device for detecting fiber faults, presence/absence of signal and wavelength of light present on an optical fiber. Audible and visual indicators of the fault/status and wavelength are provided.

Abstract: Fiber-optic communications systems are provided for optical communications networks. Fiber-optic communications links may be provided that use spans of transmission fiber to carry optical data signals on wavelength-division-multiplexing channels at different wavelengths between nodes. An apparatus and method are disclosed to use one optical light source per node to perform OTDR and LCV to satisfy safety concerns and accelerate the verification of the integrity of optical fiber links, before the application of high Raman laser powered light sources to a fiber link. A system using only one receiver per node is also disclosed.

Abstract: There is provided a distributed sensor, comprising a length of optic fibre; an interrogator unit having a detector arranged to detect light from the optic fibre, wherein the interrogator is arranged to provide distributed sensing on the optic fibre and wherein an optical path is defined between the optic fibre and the interrogator detector; a sampler coupled to the optic fibre and arranged to obtain a sample of light from the optical path of the optic fibre; a threshold detector arranged to detect the intensity of the sampled light and determine whether the intensity of the sampled light is above a threshold value; and an optical attenuator provided in the optical path and arranged to attenuate light propagating along the optical path when the intensity of the sampled light is above the threshold value. By attenuating light in the optical path if it is above a threshold value, the sensitive detector in the interrogator unit can be protected.

Abstract: A method for compensating for both material or chromatic dispersion and modal dispersion effects in a multimode fiber transmission system is provided. The method includes, but is not limited to measuring a fiber-coupled spatial spectral distribution of the multimode fiber laser transmitter connected with a reference multimode fiber optical cable and determining the amount of chromatic dispersion and modal dispersion present in the reference multimode fiber optic cable. The method also includes, but is not limited to, designing an improved multimode fiber optic cable which compensates for at least a portion of the chromatic dispersion and modal dispersion present in the reference multimode fiber optic cable resulting from the transmitter's fiber-coupled spatial spectral distribution.

Abstract: There is provided a bi-directional optical reflectometric method for characterizing an optical fiber link.

Abstract: Embodiments of the present disclosure disclose an OTDR test signal modulation circuit, including a laser diode drive, a laser diode, a current adjusting unit, and an OTDR control unit. The laser diode drive is connected to the laser diode and is configured to drive, according to an input data signal, the laser diode to transmit data light. The current adjusting unit is connected to the laser diode and the OTDR control unit and is configured to adjust a current flowing through the laser diode according to an OTDR test signal provided by the OTDR control unit, so as to modulate the OTDR test signal to the data light transmitted by the laser diode. Moreover, the embodiments of the present disclosure also disclose a passive optical network system and apparatus.

Abstract: [Task] To enable a test of an optical transmission path using an MMF with a simple configuration in an optical pulse test apparatus which is used for an SFM for long-distance transmission. [Means for Resolution] An optical coupler 22, a light source 21, a connector 23, and an optical receiver 25 are respectively connected to each other by SMF optical paths Fa to Fc. A signal processing unit 30 includes fiber type designation means 31a for designating the type of an optical fiber of a test-target optical transmission path 1 as either an SMF or an MMF, SMF parameter designation means 31b for, when an SMF is designated, designating test parameters including the refractive index of the SMF, and MMF parameter designation means 31c for, when an MMF is designated, designating test parameters including the refractive index of the MMF.

Abstract: In certain variations, fiber shape sensing or measuring systems, devices and methods are described herein, which allow for measurement of three dimensional bending as well as twist measurements of various fibers, e.g., optical fibers and fiber optic probes of various sizes. In certain variations, the systems are designed to take advantage of unique light guiding properties of optical fibers and various fiber gratings.

Abstract: An accurate measurement method and apparatus are disclosed for shape sensing with a multi-core fiber. A change in optical length is detected in ones of the cores in the multi-core fiber up to a point on the multi-core fiber. A location and/or a pointing direction are/is determined at the point on the multi-core fiber based on the detected changes in optical length. The accuracy of the determination is better than 0.5% of the optical length of the multi-core fiber up to the point on the multi-core fiber. In a preferred example embodiment, the determining includes determining a shape of at least a portion of the multi-core fiber based on the detected changes in optical length.

Abstract: A sweep sensor may include a signal source, a propagation medium, and a detector. By transmitting an interrogating signal from the signal source into the propagation medium, detectable disturbances along the medium can physically alter the characteristics of the medium, which may cause a measureable change in the backscattered signal at the detector. Based on the change, it may be possible to locate the geographic origins of the physical disturbances along the propagation medium, or to determine the nature of the disturbances, or both. For example, it is generally possible to estimate the approximate distance between the detector and the disturbance given the time required to obtain the backscattered signal and the velocity of the signal source in the propagation medium. Further, in some embodiments, it is possible to quantify the amount of disturbance.

Abstract: Disclosed is a method for measuring a fiber content of polyethyleneterephthalate (PET) and polytrimethyleneterephthalate (PTT) fibers, particularly wherein the method includes: a qualitative analysis step of identifying a presence of polyethyleneterephthalate (PET) and polytrimethyleneterephthalate (PTT) fibers in a mixed-spun fiber product; and a quantitative analysis step of measuring the fiber content by a microscopic count through difference in color between PET and PTT fibers by birefringence in a cross polarization state of a polarized light microscope (PLM). Through the present invention, it is possible to simply and accurately calculate the fiber content of PET and PTT fibers in a mixed-spun fiber material in which various kinds of fibers are mixed.

Abstract: The light source is disposed in a direction traversing the axial direction A of the optical connector. The optical connector holder comprises an inspection light reflecting portion. The inspection light reflecting portion deflects and reflects the inspection light from the light source to the axial direction A so that the inspection light enters the reference hole portion of the optical connector.

Abstract: A method for measuring propagation loss in a plane light guide plate, which includes the following steps of making an input light generated by an input light generator pass through an optical coupler, an optical reflection device individually or pass through the optical coupler first and then the optical reflection device, and finally propagate toward an optical measurement device to obtain at least one optical parameter according to the optical coupler, the optical reflection device or the combination thereof; and making the input light pass through the optical coupler and then the plane light guide plate, and further pass through the plane light guide plate from one side thereof toward the optical reflection device in order to reflect the input light toward the optical measurement device, so as to obtain a propagation loss of the plane light guide plate according to the at least one optical parameter.

Abstract: This invention relates to a distributed disturbance sensing device based on polarization sensitive optical frequency domain reflectometry (OFDR) and the related demodulation thereof. The device, adopting OFDR, polarization controlling and analysis techniques, consists of a ultra-narrow linewidth tunable laser source module, polarization generating and polarization splitting balanced detecting module, laser source optical frequency and phase monitoring module, high-speed optical switch and so on to establish a large-scale and long-distance optical sensing network. The demodulation method consists of analysis the polarization information from sensing optical fiber, the method of suppressing and compensating of the non-linear optical frequency and the laser phase noise, super-resolution analyzing, advanced denoising method and the polarization information analysis method based on Jones and Mueller's matrices using distributed wave plate model of optical fiber.

Abstract: An endoscope testing apparatus including a base, a main rail coupled to the base, a first centering mount coupled to the main rail, an optical test target holder coupled to the main rail, a second centering mount coupled to the optical test holder, the second centering mount being coaxially alignable with the first centering mount, and an optical scanning device coupled to the main rail and coaxially alignable with the first centering mount and the second centering mount. The test target holder includes an optical test target having a selectively adjustable distance between the optical test target and the second centering mount and a selectively adjustable angle formed between an axis formed by the centering mounts and the test target.

Abstract: There is disclosed a distributed optical fiber sensing system in which the sensor fiber comprises at least first and second waveguides used for separate sensing operations. The sensor fiber may be, for example, a double clad fiber having a monomode core and a multimode inner cladding.

Abstract: A seal section for use in a wellbore electrical submersible pump and includes an optic fiber detection arrangement wherein one or more optic fiber sensors is used to detect an operational parameter associated with the seal section. The operational parameters can include temperature, vibration and pressure.

Abstract: A method includes applying pulsed light to a first end of an optical fiber from an optical fault locator during a first distance test. The method includes determining an estimated distance to a fault based on the pulsed light. The method includes sending information indicative of the estimated distance to a remote device. The method also includes applying first visible light from the optical fault locator to the first end of the optical fiber to facilitate identification of the fault at a first site that is remote from the first end of the optical fiber.

Abstract: A light detector measures optical power of light incident thereon. Using a beam steering device that is rotatable about two orthogonal axes, wavelength components of different channels are scanned onto the light detector in accordance with programmable parameters. The programmable parameters specify the light detector to which the wavelength components are directed, the order the wavelength components are monitored by the light detector, and the time duration over which each of the wavelength components is monitored by the light detector.

Abstract: The present invention provides an optical waveguide element evaluation apparatus in which stray light is separated and the distribution of light angles of an optical waveguide element can be evaluated. An optical waveguide element evaluation apparatus includes optical path setting devices that image a near-field pattern at an end face of emission light from an optical waveguide element in the air; a pinhole plate that includes opening portions which the imaged near-field pattern penetrates; and a detection unit that detects the spread angle of the light at the end face of the emission light using a far-field pattern formed of the light penetrating the pinhole plate.

Abstract: A method and system for determining stress associated with a communication device, e.g., an optical fiber, and associated structures are disclosed. An exemplary method includes transmitting an initiated signal through a communication device, and comparing a reflected signal reflected by the communication device with the initiated signal. The method may further include determining a stress associated with the device from at least the comparison of the initiated signal and the reflected signal.

Abstract: An apparatus comprising an optical transmitter, a coarse tuner coupled to the optical transmitter and having a first tuning range, a fine tuner coupled to the optical transmitter and having a second tuning range smaller than and within the first tuning range, a wavelength division demultiplexer coupled to the optical transmitter and to a plurality of optical fibers, and a detector coupled to the optical transmitter and the wavelength division demultiplexer.

Abstract: An optical device that includes a first laser source, a multimode coupler optically connected to the first laser source, a first test port optically connected to the multimode coupler, a second laser source, a singlemode coupler optically connected to the second laser source, a second test port optically connected to the singlemode coupler, a photodetector, and a multimode/singlemode combiner optically connected to the multimode coupler, singlemode coupler and photodetector.

Abstract: There is provided an optical reflectometric method and system for characterizing an optical fiber link, wherein events in the fiber optic link under test are identified and values of parameters characterizing the events (e.g. location, insertion loss and reflectance) are extracted from an analysis of one or more reflectometric measurements performed on the optical fiber link. A loss profile and/or a reflectance profile are then constructed. The loss and reflectance profiles are typically displayed on screen or otherwise graphically represented for an operator to be able to appreciate the measurement results at a single glance.

Abstract: Problems of excessive fading in systems for monitoring single-mode optical fiber for physical disturbances are addressed by launching into the fiber polarized light having at least two different predetermined launch states of polarization whose respective Stokes vectors are linearly-independent of each other; downstream from the first location, receiving the light from the fiber; analyzing the received light using polarization state analyzer means having at least two different analyzer states of polarization that are characterized by respective Stokes vectors that are linearly-independent of each other and detecting the analyzed light to provide corresponding detection signals; deriving from the detection signals measures of changes in polarization transformation properties of the fiber between different times that are substantially independent of said launch states and said detection states; and, on the basis of predefined acceptable physical disturbance criteria determining whether or not the measures are i

Abstract: Systems and methods for calculating a relative temperature of a fiber-optic cable using bi-directional analysis traces with an optical time-domain reflectometer (“OTDR”). Analysis of bi-directional traces along a length of fiber-optic cable yields a scaled local backscatter coefficient of the fiber. Accordingly, an initial set of measurement data is collected at a first time interval and a base scaled local backscatter along a fiber is calculated. A subsequent set of measurement data is collected at a second time interval and a subsequent scaled local backscatter along the fiber is calculated. The exemplary systems and methods described herein determines a change in scaled local backscatter as a function of a difference between the base scaled local backscatter and at least the subsequent scaled local scaled local backscatter along the fiber, and then determines a relative temperature variation of the fiber as a function of the change in scaled local backscatter.

Abstract: Provided is a signal identifying apparatus for an optical fiber that includes a detecting portion capable of detecting a signal originating from a first end of the optical fiber and a signal originating from a second end of the optical fiber. Additionally, the signal identifying apparatus includes an identifying portion that identifies a desired signal by separating the signal originating from the first end of the optical fiber from the signal originating from the second end of the optical fiber.

Abstract: A client unit and a method are provided performing fault analysis in a Passive Optical Network, PON, by using Optical Time Domain Reflectometry, OTDR. The method comprises triggering a new OTDR measurement, wherein a previous reference measurement has been made indicating an original state of the PON. The method further comprises inserting an OTDR measurement signal into a multistage splitter before a last splitter stage of the multistage splitter, and wherein the last splitter stage is of ratio 2:N; and obtaining at least one new event location based on the OTDR measurement signal. Further, the method comprises calculating a fault magnitude at a given location by subtracting an event magnitude obtained from the new OTDR measurement from the reference OTDR measurement and taking into account the number of drop links connected to the last splitter stage in the reference measurement and the new measurement. Thereby, determination of position and severity of the fault locations is enabled.

Abstract: An optical fiber characteristic measuring device of the present invention includes: a light source which emits laser light modulated at a predetermined modulation frequency; an incident section which causes the laser light from the light source as continuous light and pulsed light to be incident from one end and other end of an optical fiber respectively; a timing adjuster which causes light emitted from the optical fiber to pass therethrough at a predetermined timing; and a light detector which detects the light which passes through the timing adjuster, and measures a characteristic of the optical fiber by using a detection result of the light detector, and the device includes: a synchronous detector which synchronously detects the detection result of the light detector by using a synchronization signal having a predetermined frequency; and a frequency setter which changes the frequency of the synchronization signal in a case where the modulation frequency at the light source is an integer multiple of the fr

Abstract: The present invention discloses a Wavelength Division Multiplexing Filter which can satisfy coexistence requirements of different PON systems and an optical line detecting system.

Abstract: Apparatus and method of simultaneously measuring a parameter of a plurality of cores in at least one optical fiber. An input tester at a first end of the test fiber has a plurality of tester signal inputs with a geometry substantially matching at least a portion of the core geometry of the fiber. At least one test input signal source coupled to the plurality of tester signal inputs. A signal measuring device is alignable at a second end of the fiber to measure the output of the test input signal. The input tester may include a tapered multicore coupler or a laser having a shield with apertures disposable between the laser and the fiber. In the latter case, a lens may be disposed between the shield and the fiber to project light from the laser that passes through the apertures onto the end of the fiber.

Abstract: There is provided an optical fiber communication system restricting enlargement of the diameter of an optical fiber as well as enabling achievement of a large-capacity optical communication with a small number of optical fibers. An optical fiber communication system 100 includes an optical transmitter 10 transmitting a plurality of optical signals in parallel, a multicore fiber 20 in which outer circumferences of a plurality of cores are covered with a common clad, and the respective optical signals transmitted in parallel from the optical transmitter 10 are input into the cores, and an optical receiver 30 receiving the optical signals output in parallel from the respective cores of the multicore fiber, wherein the optical transmitter 10 and the optical receiver 30 perform a MIMO communication.

Abstract: A radiation passing layer has a top surface and a bottom surface below which a proximity sensor is positioned. A radiation shield is between the emitter and the detector, and extends to the bottom of the radiation passing layer. A radiation absorber being a separate piece and of a different material than the shield is positioned to provide a radiation seal between the top surface of the shield and the bottom surface of the radiation passing layer. Other embodiments are also described and claimed.

Abstract: A test receiver for use with an Optical Time Domain Reflectometer (OTDR), including a first receive fiber having a first attribute, and a second receive fiber having a second attribute different from the first attribute. The attributes may be lengths, marker events, or both. This configuration reduces the number of times an OTDR operator must travel back and forth between cable ends when testing fibers.

Abstract: To efficiently apply jitter to an optical signal using a simple configuration, provided is an optical signal output apparatus that outputs an optical pulse pattern signal including jitter, the optical signal generating apparatus comprising a light source section that outputs an optical signal having an optical frequency corresponding to a frequency control signal; an optical modulation section that modulates the optical signal output by the light source section, according to a designated pulse pattern; and an optical jitter generating section that delays an optical signal passed by the optical modulation section according to the optical frequency, to apply jitter to the optical signal.

Abstract: Subject matter disclosed herein relates to measuring modes of a waveguide.

Abstract: To allow for the characterization of a passive optical network, reflectometry data is closely analyzed to determine reflection events within the data, and to subsequently characterize the reflection events so the status, operating parameters and efficiency of the network can be monitored. The reflectometry data is analyzed using statistical techniques to identify and analyze reflection events, which will ultimately allow meaningful reports to be generated which characterize the operation of the passive optical network. The reports can thus be provided to operators and/or installers to determine the health of the network, and whether any revisions are necessary.

Abstract: A sweep sensor may include a signal source, a propagation medium, and a detector. By transmitting an interrogating signal from the signal source into the propagation medium, detectable disturbances along the medium can physically alter the characteristics of the medium, which may cause a measurable change in the backscattered signal at the detector. Based on the change, it may be possible to locate the geographic origins of the physical disturbances along the propagation medium, or to determine the nature of the disturbances, or both. For example, it is generally possible to estimate the approximate distance between the detector and the disturbance given the time required to obtain the backscattered signal and the velocity of the signal source in the propagation medium. Further, in some embodiments, it is possible to quantify the amount of disturbance.

Abstract: A detector sequentially detects intensity distribution of transmitted light which is transmitted through a center portion of a preform. A determining section determines at least one of a position of a through hole and a size thereof on the basis of a time series of a feature value in the intensity distribution.

Abstract: A method of improving the performance of an optical time domain reflectometer (OTDR) is provided. The method according to an embodiment of the present invention can increase accuracy of a distance of the OTDR through an initial calibration method with respect to the refractive index of an optical fiber, and can accurately detect a fault position and accurately analyze a fault cause through a real-time calibration method with respect to the refractive index of the optical fiber when faults and performance degradation occur.

Abstract: Provided is a chromatic dispersion measurement device including a light branching unit that divides a incident measured light signal into a first measured light signal and a second measured light signal and causes a frequency difference between the first measured light signal and the second measured light signal when the signals are output, an optical phase shifter provided in either one of the first branch path and the second branch path having a polarization maintaining characteristic and periodically changing a phase ?i of the measured light signal, an optical combination unit that combines the first measured light signal and the second measured light signal and outputs an interference element of an i-th optical component obtained by interference of the first measured light signal and the second measured light signal when the phase difference is the phase ?i, as a combined measured light signal.

Abstract: A measurement system comprising an analog position sensitive device is provided that can measure the XY position of a plurality of light beams at very high resolution. In accordance with one exemplary associated method, a connector bearing one or more optical fibers is fixedly positioned before a position sensing detector so that light emanating from the ends of the optical fibers will strike the position sensing detector. A light beam is passed through at least one opening in the connector, such as a guide pin hole onto the detecting surface of the PSD to establish the position of the connector. Next, each optical fiber in the connector is individually illuminated sequentially so that the light emanating from the fiber falls on the position sensing detector. The locations of all of these light beams striking the PSD are compared to position of the light beam passed through the guide pins and/or to each other to determine if all the fibers are in the correct positions relative to the connector.

Abstract: A test pulse is generated from a first and a second test light beam pulse with different wavelengths, with a predetermined time difference applied between the first and the second test light beam pulse. A circulator inputs the test pulse to a trunk fiber of a measurement target fiber line. A reflected light is extracted which is output from an input end of the trunk fiber. A filter extracts stimulated Brillouin backscattered light. A receiver receives and converts the scattered light into an electrical signal. A processing device carries out the signal to determine in which of N branched fibers the stimulated Brillouin scattered light is generated, while varying a time difference between the first and the second test pulse.

Abstract: Techniques for analyzing output modal content of optical fibers that support more than one spatial mode are disclosed. These techniques are based on spatially resolving interference between co-propagating modes and constructing a spatial beat pattern between the co-propagating modes. By doing so, these techniques provide information about the modes that propagate along the optical fiber.

Abstract: A test instrument comprises plural first optical signal sources at a first wavelength and a distributor coupled to the plural first optical signal sources to supply the signals produced to a multi-fiber test port. Additional second wavelength signal sources may be provided, and a second test instrument for use at a second end of the link under test may be provided, to effect testing of the optical link.

Abstract: A method of measuring the bandwidth of a multi-mode optical fiber using single-ended, on-line and off-line approaches and test configurations. The method includes: transmitting a light signal through the first end of a multi-mode fiber toward the second end of the multi-mode fiber, so that a portion of the light signal is reflected by the second end toward the first end of the multi-mode fiber; and receiving the reflected portion of the light signal at the first end of the multi-mode fiber. The method also includes obtaining magnitude and frequency data related to the reflected portion of the light signal at the first end of the multi-mode fiber; and analyzing the magnitude and the frequency data to determine a bandwidth of the multi-mode optical fiber. The length of the multi-mode fiber may also increase over time during testing.

Abstract: A portable optical fiber test set controllable through a wireless mobile device includes: a portable optical fiber tester, which has a communication interface and can test an optical fiber; and a wireless mobile device electrically connected to the communication interface, so that the wireless mobile device can control the portable optical fiber tester to test the optical fiber and can upload test results and data, obtained by the portable optical fiber tester, to a cloud through a wireless network or download data from the cloud. The invention utilizes the portable optical fiber tester, which has the communication interface and works in conjunction with a function of the wireless mobile device connecting to the network whenever network is available, so that the invention becomes the portable optical fiber testing device that can be conveniently carried and used.

Abstract: A system and method for detection and identification of unknown samples using a combination of Raman and LIBS detection techniques. A first region of a sample and a second region of a sample are illuminated using structured illumination to thereby generate a first plurality of interacted photons and a second plurality of interacted photons. This first plurality and second plurality of interacted photons may be passed through a fiber array spectral translator device. Said first plurality of interacted photons are assessed using Raman spectroscopy to thereby generate a Raman data set. Said second plurality of interacted photons are assessed using LIBS spectroscopy to thereby generate LIBS data set. These data sets may be analyzed to identify the sample. These data sets may also be fused for further analysis.

Abstract: An optical fiber grating tracker includes a first stub, a second stub, an optical fiber grating, and a connection part. The connection part has a through hole. The first stub is inserted into one end of the through hole. The second stub is inserted into the other end of the through hole. An interval exists between the first stub and the second stub. The optical fiber grating is in the through hole and in the interval. A space in the through hole is filled with a waterproof material. The optical fiber grating tracker and the method for detecting an optical fiber line fault can detect an optical fiber fault from an optical fiber truck to the optical fiber grating tracker through an optical splitter, and meanwhile do not affect normal communication of an original optical communication network.