A co-cable probability detection method, including obtaining information about at least two first events and at least two second events, where the information about the at least two first events is obtained based on a first sounding signal in a first transmission medium, the information about the at least two second events is obtained based on a second sounding signal in a second transmission medium, the information about the first events indicates at least one cable segment on the first transmission medium, and the information about the second events indicates at least one cable segment on the second transmission medium, and obtaining, based on the information about the first events and the second events, a probability that the at least one cable segment on the first transmission medium and the at least one cable segment on the second transmission medium comprise a co-cable segment.

In some examples, optical fiber identification and distance measurement may include utilizing a reflectometer and optical fiber connection device that includes a Rayleigh wavelength pass filter to pass, in one direction, an optical reflectometer signal to an optical fiber. The reflectometer and optical fiber connection device may include a Raman wavelength pass filter to filter out, in another direction, Rayleigh backscattering from the optical reflectometer signal. Further, the Raman wavelength pass filter may pass, in the another direction, a Raman Anti-Stokes signal from the optical fiber.

This application discloses a same-cable probability detection method. The method includes: obtaining a first characteristic parameter of a first optical signal and a second characteristic parameter of a second optical signal, where the first optical signal is a signal transmitted in a first optical fiber, the second optical signal is a signal transmitted in a second optical fiber, the first characteristic parameter is generated after the first optical signal is affected by a vibration of the first optical fiber, and the second characteristic parameter is generated after the second optical signal is affected by a vibration of the second optical fiber; and obtaining, based on the first characteristic parameter and the second characteristic parameter, a probability that at least one optical cable segment of the first optical fiber and at least one optical cable segment of the second optical fiber include a same-cable segment.

A method and a system for interrogating an optical fiber includes a probe signal that has a first frequency comb at a first repetition rate (Δf) injected into the optical fiber. A backscattering signal that includes the probe signal convolved with an impulse response of the optical fiber in reflection which is sensitive to at least one parameter being measured from the optical fiber is gathered. The backscattering signal is beaten with a local oscillator signal to generate a beating signal, the local oscillator signal including a second frequency comb at a second repetition rate that is offset from the first repetition rate (Δf+δf) and being mutually coherent with the first frequency comb. The resulting beating signal is analysed to thereby determine the at least one parameter being measured from the optical fiber.

According to examples, a fiber element offset length-based optical reflector peak analysis apparatus may include an optical element optically connected to a laser source that emits a laser beam. The optical element may include a pre-set offset length between a plurality of adjacent branches. The fiber element offset length-based optical reflector peak analysis apparatus may further include an optical time-domain reflectometer (OTDR) to generate, based on optical reflection signals received from corresponding optical reflectors attached to devices under test (DUTs) that are attached to the plurality of adjacent branches, an OTDR trace that qualifies each of the DUTs.

An optical detection unit detects a return light and outputs a detection signal. An optical multiplexer/demultiplexer outputs the monitoring light to the optical transmission line, and outputs the return light to the optical detection unit. A processing unit detects a first timing at which the detection signal becomes less than a first threshold value, detects a second timing at which the detection signal becomes less than a second threshold value, and calculates a first change rate of the detection signal in a period between the first and second timings. The processing unit changes the first and second threshold values to calculate the first change rate for a plurality of periods, and, when a second change rate between the first change rates in two adjacent periods is greater than a threshold value, either of the first and second timings in one period is detected as the breakage position.

An object is to provide an optical pulse test method and an optical pulse test device with which it is possible to measure transmission losses of a basic mode and a first higher-order mode at a connection point at which two-mode optical fibers are connected in series, without switching the mode of input test light. An optical pulse test device according to the present invention inputs a test optical pulse in a basic mode (or a first higher-order mode) from one end of an optical fiber under test, the test optical pulse having such a wavelength that the test optical pulse can propagate in the basic mode and the first higher-order mode, measures intensity distributions of a basic mode component and a first higher-order mode component of return light of the test optical pulse relative to the distance from the one end, finds, from the intensity distributions, losses of the basic mode component and the first higher-order mode component of the return light at a desired connection point of the optical fiber under test, and calculates transmission losses of the basic mode and the first higher-order mode at the connection point based on expressions (8) (or expressions (9)).

An optical fiber connection measurement system configured to test distal connection quality of individual outgoing optical fibers at a hub includes a test module to test a distal connection quality of one of the individual optical fibers at a time. The optical fiber connection measurement system includes a controller connected to the test module, and a switch arranged between the test module connected to an input of the switch and proximal ends of the outgoing optical fibers in the hub connected to outputs of the switch. The switch is connected to the controller and a communication module connected to the controller. The controller is configured to receive a test request via the communication module, to set the switch to optically connect the test module, a proximal end of one of the optical fibers associated with the distal end, and to activate the test module to test the connection quality.

Aspects of the subject disclosure may include, for example, determining distinct timing offsets between an input port and output ports of a multiport optical device. An optical signal is injected at an input port of the device to obtain output signals at the output ports, which are injected into downstream fibers. An optical multipath return signal is received via the input port of the device, including a combination of measured events including reflections, backscatter, or both. A number of similar events expected in the number of downstream optical fibers is calculated to obtain an expected multipath signature based on configuration data. Results of the optical multipath return signal are then compared to the expected multipath signature to obtain comparison results. One of the measured events is distinguished from the others based on the first comparison results and the distinct timing offsets. Other embodiments are disclosed.

A system for providing advanced characterization of an optical fiber span is based upon the use of a pair of optical time domain reflectometers (OTDRs), located at opposing end terminations of the span being characterized. Each OTDR performs standard reflectometry measurements and transmits the resulting OTDR trace to monitoring equipment in a typical manner. The pair of OTDR traces is thereafter combined in a particular manner (“stitched together”) to create an OTDR trace of the entire fiber span (essentially doubling the operational range of prior art OTDR measurement capabilities). The transmit portion of one OTDR may be paired with the receive portion of the other OTDR, with time-of-light measurements (or signal loss measurements) used to determine optical path length and/or optical signal loss of the span. Using a multi-wavelength light source in the paired transmit/receive arrangement allows for a characterization of chromatic dispersion of the span.