Abstract: A method and system of measuring the PMD of an optical fiber under test (FUT). A polarization-sensitive optical time domain reflectometer (POTDR) is used to inject into the FUT and from a proximal end thereof, a test signal comprising a series of repeated light pulses and detecting a corresponding polarization-analyzed return light signal coming back from the optical fiber and representing back-reflected light from a light reflector connected to a distal end of the FUT. The plurality of polarization-sensitive acquisitions defines at least one pair of acquisitions performed with mutually different but closely-spaced wavelengths and substantially the same state of polarization (SOP). The process may be repeated for a plurality of pairs of acquisitions performed with at least one of a plurality of mutually-different center wavelengths and a plurality of mutually-different SOPs, and a value of the PMD for the FUT is calculated therefrom.

Abstract: There is provided a method and an apparatus of fiber optic distributed acoustic sensing (DAS) which can use low-cost coherent laser as well as low-cost acquisition and processing electronics and which can still provide reliable monitoring results for optical fiber monitoring and troubleshooting applications in optical fiber telecommunication networks. Such low-cost solution is made possible by employing grouped data signal processing. Data is processed over independent groups of data to provide an independent DAS signal for each group. This allows measurements to be less sensitive to laser fluctuations and thereby reduces coherent laser technical specification requirements and allows the use of a low-cost coherent laser (thereby reducing the cost of the laser) as well as low-cost acquisition and processing electronics.

Abstract: There is provided a method and system of frequency dithered distributed acoustic sensing (FD-DAS) using group data signal processing, where the continuous wave (CW) coherent laser's optical frequency or optical phase for the FD-DAS interrogator may be set in evenly or randomly distributed manner for different data groups but they are kept as constant or with negligibly variation within each data group. Such FD-DAS may be used to improve acoustic or vibration signal measurement reliability, to allow to use a low-cost single-frequency laser such as a DFB laser, and/or to suppress polarization fading effect.

Abstract: A Radio Frequency (RF) spectrum analyzer includes an RF front end including a single antenna configured to monitor a wireless network that includes Time Division Duplexing (TDD); and circuitry connected to the RF front end and configured to operate and monitor the wireless network both in a spectrum analyzer mode and a signal analyzer mode, utilize the signal analyzer mode to extract synchronization information from the monitored wireless network, derive a start of frame of a radio frame from said the synchronization information; and utilize the synchronization information to identify an acquisition window to synchronize a gate in the spectrum analyzer mode.

Abstract: Provided herein is a solution for measuring the optical power loss of duplex optical-fiber devices under test, and particularly those terminated with a duplex connector interface, which allows for a one-cord testing method whichever the format of the duplex connector interface of the optical-fiber device under test, without disconnecting the optical fibers of the device under test from their duplex native connector interface. Provided is an optical-fiber expansion device used to interconnect and adapt a power meter instrument to a variety of duplex connectors. The optical-fiber expansion device comprises a pair of optical fibers having a core diameter and a numerical aperture greater than the optical fiber in the DUT connector interface, to make it compatible with the one-cord testing method. Interchangeable optical-fiber expansion devices can be used to match the power meter interface on one side, to various duplex connector interfaces under test on the other side.

Abstract: There is provided an adapter tip to be employed with an optical-fiber connector-endface inspection microscope device and an optical-fiber connector endface inspection microscope system suitable for imaging the endface of a duplex optical-fiber connector. Because of the distance between the ferrules of a duplex connector, the field of view of a typical single-fiber or multi-fiber inspection microscope may not be wide enough to allow inspection of both ferrules at once. The proposed adapter tip or microscope system may comprise relay optics configured to laterally shift the optical path of the light beam reflected from one optical fiber endface (corresponding the first ferrule) toward that from the other optical fiber endface (corresponding the second ferrule), so that both endfaces may be imaged within the field of view of the inspection microscope.

Abstract: Systems and methods for performing Optical Time-Domain Reflectometry (OTDR) tests on optical fibers are provided. In an embodiment, a method includes applying OTDR pulses to a fiber under test and receiving noisy acquisition sets of the fiber under test; processing the noisy acquisition sets with a denoising model that is a pre-trained machine learning model configured to simultaneously use spatial information and temporal information associated with the noisy acquisition sets to filter out noise; and analyzing outputs from the denoising model to determine characteristics of the fiber under test. This approach is performed in lieu of the conventional approach of mathematically averaging acquisitions, thereby resulting in proper results with fewer acquisitions, significantly speeding up the overall acquisition time.

Abstract: Systems and methods for detecting faulty optical fibers. A method, according to one implementation, includes collecting data associated with an optical fiber network, wherein the data includes optical fiber performance data, and data associated with one or more environmental factors; performing a first linear regression analysis on the data; performing a second linear regression analysis on results of the first linear regression analysis; and determining one or more issues relating to the optical fiber network based on results of the second linear regression analysis.

Abstract: Described herein are systems and methods for testing connectivity of strands of a fiber optic cable, the ends of which terminate at a first site and a second site. A method, according to one implementation, includes the step of coordinating the first and second sites to generate a signal at a first end of the strands and to detect presence of the signal at a second end of the strands. The method also includes receiving confirmation information from the first and second sites pertaining to the signal being generated and detected. Also, the method includes the steps of utilizing the confirmation information to match the first end of the strands with the second end of the strands for determining fiber strand connectivity between the first site and the second site and then creating a connectivity map showing the fiber strand connectivity.

Abstract: Systems and methods for inspecting optical fibers are provided. A method, according to one implementation, includes steps of obtaining an image of an end-face of an optical fiber; analyzing the image with a pre-trained neural network model to classify pixels therein as any of a defect, a scratch, or clean; aggregating the pixels based on proximity to obtain defect segments or scratch segments; characterizing these defect segments and scratch segments based on but not limited to size and location, and providing an output including any of the defect segments or scratch segments.

Abstract: Systems, methods, and devices for testing optical fibers are provided. According to one implementation, an optical fiber testing apparatus may include an optical test unit configured to obtain a characterization of an optical fiber to be tested. Additionally, the optical fiber testing apparatus may include a visible light source and an analysis and control device. For example, the analysis and control device may be configured to adapt the visible light source to a specific power level based on the characterization of the optical fiber.

Abstract: Systems, methods, and devices for testing for faults in a fiber optic cable are provided. A Visual Fault Locator (VFL), according to one implementation, includes an output port configured for connection with an optical fiber to be tested. The VFL also includes a variable light source configured to emit visible light at different power levels from the output port. For example, the different power levels may correspond with different light intensity levels. In some implementations, the VFL may further include a gain control device connected to the variable light source, whereby the gain control device may be configured to control the power of the variable light source to enable the variable light source to emit the visible light at multiple power levels.

Abstract: There are provided systems and methods for inspecting an endface of an optical-fiber connector using an optical-fiber connector endface inspection microscope system comprising one or more image detectors for capturing images over the whole endface to be inspected. An illumination system comprises two or more illumination sources disposed so as to illuminate respective regions over the connector endface and to prevent dark zones in the capture images. The illumination sources are activated in sequence, such that adjacent sources are never activated at the same time, and corresponding images captured in sequence, i.e., one after the other. In this case, it is also possible to activate the illumination sources in sequence, such that adjacent sources are never activated at the same time. Activating the illumination sources separately eliminates the illumination overlap and so eliminates the double image artifact. This allows for a more uniformly lit image with less dark spots.

Abstract: There is provided an optical-fiber connector endface inspection microscope system for inspecting an endface of an optical-fiber connector. It comprises one or more image detector for capturing at least one image of the endface to be inspected; an objective lens system comprising a focusing lens for adjusting a focus of the objective lens system on the image detector and a fixed relay lens; a main housing structure enclosing the image detector and the focusing lens; and at least one interchangeable optical head releasably connectable to the main housing structure and enclosing the fixed relay lens, wherein the optical head is releasably connectable to an adapter tip for interfacing with the optical-fiber connector to be inspected.

Abstract: An embodiment involves obtaining a tabular data set with columns that characterize items relating to behavior of components of a communication network; constructing a frequent-pattern tree, each node being associated with: (i) an item-name for representing an item, (ii) a count of transactions from a root node of the tree to the respective node, and (iii) node-links that refer to other nodes in the tree that represent items having the same item-name; traversing the tree to identify a set of nodes with counts greater than a predefined support threshold; generating, from the nodes, association-rules that are based on antecedent items associated with a target item; reducing the association-rules by (i) removing the association-rules in which the antecedent items thereof are a superset or subset of the antecedent items of a further association-rule, or (ii) combining the association-rules that have antecedent items that are at least partially disjoint and conditionally dependent.

Abstract: There is provided a technique to reduce the Rayleigh coherence noise in OTDR measurements using spectral averaging of OTDR traces while at least partly cancelling chromatic dispersion pulse broadening on the averaged OTDR trace by applying a chromatic dispersion correction prior to averaging the OTDR traces. By correcting for chromatic dispersion pulse broadening, it allows to reduce the Rayleigh coherence noise without impacting the OTDR spatial resolution.

Abstract: There are provided herein test instruments, devices and methods for measuring the optical power loss of optical-fiber devices under test, and particularly those terminated with multifiber connectors, which allows for a one-cord or one-cord equivalent reference method whichever the pinning of the actual optical-fiber device under test. There is proposed to add an optical-fiber expansion device to convert the pinning of the input interface of the power meter instrument from pinned to unpinned or vice-versa, while not adding extra measurement uncertainty. This is accomplished using a patch cord which core diameter is between that of the device under test and that of the input interface of the power meter instrument.