An optical fiber characteristics measurement system includes: an optical fiber characteristics measurement device including: an emission port configured to emit probe light; and an incidence and emission port connected to one end of a measurement target optical fiber and configured to emit pump light, stimulated Brillouin scattered light generated within the measurement target optical fiber being incident on the incidence and emission port; a first optical fiber having one end connected to the emission port and configured to guide the probe light to another end of the measurement target optical fiber; and an optical isolator provided between another end of the first optical fiber and the another end of the measurement target optical fiber, and configured to cause the probe light guided by the first optical fiber to be incident on the another end of the measurement target optical fiber.

The present invention is to provide a backscattered light amplification device, an optical pulse test apparatus, a backscattered light amplification method, and an optical pulse test method for amplifying a desired propagation mode of Rayleigh backscattered light with a desired gain by stimulated Raman scattering in a fiber under test having the plurality of propagation modes. The backscattered light amplification device according to the present invention is configured to control individually power, incident timing, and pulse width of a pump pulse for each propagation mode when the pump pulse is incident in a plurality of propagation modes after the probe pulse is input to the fiber under test in any propagation mode.

An optical pulse test apparatus according to the present disclosure includes a light generation unit configured to generate an optical pulse for generating backscattered light beams in an optical fiber under test and generate first light having an optical frequency for amplifying backscattered light in an LP11 mode out of the backscattered light beams in two LP modes through stimulated Brillouin scattering, and second light having an optical frequency for attenuating backscattered light in an LP01 mode out of the backscattered light beams in the two LP modes through stimulated Brillouin scattering, a mode demultiplexing unit configured to input the optical pulse, the first light, and the second light generated by the light generation unit into the optical fiber under test in the LP01 mode and separate, out of the backscattered light beams generated by the optical pulse, the backscattered light in the LP11 mode, a local oscillation light generation unit configured to generate local oscillation light by which the backscattered light separated by the mode demultiplexing unit is heterodyne-detected, a light reception unit configured to multiplex the backscattered light in the LP11 mode separated by the mode demultiplexing unit and the local oscillation light generated by the local oscillation light generation unit and photoelectrically convert the multiplexed light into an electrical signal, and an arithmetic processing unit configured to calculate a time-intensity distribution of the electrical signal obtained by the light reception unit photoelectrically converting the backscattered light in the LP11 mode.

A system that provides detection, annunciation, mitigation, and alleviation of stress attacks by executing algorithms based on measurement of intensity of light. The system determines to execute algorithms to take programmed action based on potential effects of a detected stress attack. The system can be used, for example, to determine the position of potential attacks to conduits that transport electricity, oil, gas, foodstuffs, water, people, and materials.

A measurement system includes a cable having a length, a light source, at least one detector, and at least one processor. The light source is operably coupled to the cable and is configured to transmit an optical signal to the cable. The at least one processor is operably coupled to the cable and configured to: receive a scattered signal from the cable responsive to the optical signal transmitted to the cable; map the scattered signal to the length of the cable; and de-convolve a spatial averaging effect of the scattered signal using a weighting profile corresponding to the light source and the cable to generate a distributed property profile defined along the length of the cable.

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.

The disclosed systems and methods for characterizing an optical fiber in a dense wavelength division multiplexing (DWDM) optical link. The characterizing comprising: i) applying a power dither to data bearing optical signals propagating in the optical fiber, the power dither having a high-power level and a low-power level; ii) computing optical time-domain reflectometer (OTDR) traces corresponding to the high-power level and the low-power level of the power dither; iii) averaging the OTDR traces corresponding to the high-power level and the OTDR traces corresponding to the low-power level into average OTDR traces; computing a differential Stimulated Raman Scattering (SRS) gain from the OTDR traces; and iv) adjusting the average OTDR traces based on the differential SRS gain.

A method of optical sensing comprises coupling an excitation optical signal into a first optical fiber to induce Rayleigh backscattering, thereby providing a backscattered signal. The backscattered signal is optically amplified in the first optical fiber, thereby providing an amplified backscattered signal. The amplified backscattered signal is coupled into a second optical fiber and is optically re-amplifying in the second optical fiber.

Systems and methods are disclosed for dynamic addressing of optical fiber sensors in fiber optic interferometry systems. Events that occur along the optical fiber span have defining attributes such as location along the optical fiber span, type, magnitude, time of occurrence, and duration. The event attributes may be used to dynamically form a unique address that fully defines and identifies the event. Other information, such as the corresponding identifier for one or more of the optical fiber span and the corresponding fiber optic interrogator may be included as part of the unique address.

The present invention is to provide a backscattered light amplification device, an optical pulse test apparatus, a backscattered light amplification method, and an optical pulse test method for amplifying a desired propagation mode of Rayleigh backscattered light with a desired gain by stimulated Brillouin scattering in a fiber under test having the plurality of propagation modes. The backscattered light amplification device according to the present invention is configured to control individually power, incident timing, and pulse width of a pump pulse for each propagation mode when the pump pulse is incident in a plurality of propagation modes after the probe pulse is input to the fiber under test in any propagation mode.