EXFO Inc.

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.

There is provided a method for measuring the spectral transmission response of a DUT using a multi-wavelength Optical Time Domain Reflectometer (OTDR) which allows performing OTDR measurements across a spectral range of interest. The OTDR targets a single reflective OTDR event along the OTDR trace, e.g., a mirror, a non-angled polished (UPC) connector or any other reflective surface located at the remote end of the DUT, which reflectance peak in combination with a reference measurement allows to perform single-end measurements of the transmission response. The process is repeated at various wavelengths to obtain a spectral transmission response of the DUT.

There is provided an optical-fiber connector endface inspection microscope device that is natively designed for inspecting angled-polished (APC) optical-fiber connectors, i.e., without requiring an angled adapter tip or optical components in the adapter tip to deviate light reflected from the optical-fiber endface. Adapter tips are still needed to adapt the microscope device to different types of connectors, but they are small, straight, and low cost. This can be achieved using optics configured to deviate the illumination path so illumination light exits the inspection microscope device along an illumination path that is at an angle that is substantially egal to 8 degrees, so as to illuminate the connector endface in a direction that is substantially normal to the angled-polished endface to be inspected.

A method of locating a hollow-core fiber segment amongst silica core segments in optical fiber link is provided. An OTDR test instrument sends test signals along the fiber link and a Rayleigh backscatter level as a function of distance along the optical fiber link of returning signals is measured. The position of the proximal extremity of the hollow-core optical fiber segment is identified by locating a discrete drop greater than a drop threshold value in the Rayleigh backscatter level. The position of the distal extremity of the hollow-core fiber segment is identified by locating one of a discrete step greater than a step threshold value in the Rayleigh backscatter level and end-of-fiber indicator. The drop threshold value and the step threshold value are commensurate with a difference between a Rayleigh backscatter level in hollow-core optical fibers and in the type of silica core optical fibers of the optical fiber link.

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.

There are provided coded-sequence OTDR methods and devices which diminish or erase artefacts created in the OTDR trace by performing multiple coded-sequence OTDR acquisitions with mutually different inter-pulse intervals so as to change the positions of the artefacts in the OTDR traces derived from these OTDR acquisitions and combining the multiple OTDR traces to reconstruct a reconstructed OTDR trace.

There is therefore provided an optical-fiber connector endface inspection microscope device that can support inspection of both angled-polished (APC) and non-angled-polished (UPC) optical-fiber connectors without the need to change the adapter tip. Adapter tips are still needed to adapt the microscope device to different formats of connectors, but they can be small, straight, and low cost, and most of all, they don't need to be changed between APC and UPC connector inspection. This can be achieved using an inspection microscope device comprising two modes of operation, i.e., one for UPC inspection and one for APC inspection, which are associated with distinct illumination paths.

Methods and systems for identifying one or more common optical path portions between a first and a second deployed optical fibers of a communication network are disclosed. Each of the first and second deployed optical fibers are potentially affected by vibration events therealong. A method includes performing a plurality of successive acquisitions, each acquisition comprising sending at least one test signal sensitive to the vibration events in the first and second deployed optical fibers and receiving at least one return test signal therefrom, locating the vibration events affecting the first and second deployed optical fibers based on the received at least one return test signal over said plurality of acquisitions, determining a correspondence between the vibration events located along the first and the second deployed optical fiber, respectively and identifying the one or more common optical path portions between the first and second optical fibers based on said correspondence.

Methods and systems for referencing an optical power loss measurement (OPLM) system, and methods and systems for measuring an optical insertion loss of an optical device under test (DUT) using an OPLM system referenced as such. The herein-provided reflectometric one-cord referencing method combines the capabilities of an OPLM system with that of an Optical Time Domain Reflectometer (OTDR). A first test unit comprises an optical source that is used as the light source in the OPLM. A second test unit comprises a power meter which is used as the power meter in the OPLM measurement. Either the first or the second test unit comprises an OTDR acquisition device. The reflectometric one-cord reference measures the connector loss along the reference link using OTDR capabilities of the test unit(s). Once the power reference of the OPLM devices is obtained, the reflectometric one-cord reference method may determine the optical insertion loss of the DUT while eliminating the measured connector loss.

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.