Abstract: An object of the present invention is to provide a Brillouin gain spectrum distribution measuring method and apparatus capable of measuring a BGS, having a line width narrower than usual, in a distributed manner in the longitudinal direction of an optical fiber under test. This measuring apparatus prepares pump light in which a pulse is added to continuous light and probe light of continuous light in which a frequency is shifted from the pump light, makes the probe light incident on one end of the FUT and the pump light incident on the other end, and obtains a time waveform of a component amplified by the pump light pulse of a probe light intensity amplified by the pump light. This measuring apparatus changes an optical frequency difference between the pump light and the probe light, and obtains a time waveform for each optical frequency difference. This measuring apparatus obtains a BGS distribution of the FUT from these time waveforms.

Abstract: An object of the present disclosure is to provide a method for remotely identifying a utility pole position and estimating a state of an overhead optical fiber cable. The present disclosure is a method for identifying a utility pole position including identifying a boundary region of a vibration distribution as a utility pole position, from a vibration distribution pattern obtained by measuring strain amounts with respect to distances of an optical fiber by an optical fiber vibration distribution measuring method at each time and sequentially stacking the strain amounts.

Abstract: The present disclosure is an optical line test system that detects a distribution of loss points of an optical line in a longitudinal direction, using a coherent light measurement device, applies vibration to facility disposed on a path of the optical line, detects a vibration point of the optical line in a longitudinal direction upon applying the vibration, using the coherent light measurement device, and identifies the loss point based on correspondence between the detected loss point and vibration point.

Abstract: An object of the present invention is to provide a facility position specification system, a cover, and a facility position specification method capable of specifying a route of an overhead cable without directly giving disturbance to the overhead cable itself.

Abstract: The present disclosure relates to an optical fiber strain measurement method including, in order: a strain amount measurement step S2 of measuring a strain amount ?n? of each core wire of an optical fiber ribbon F; a torsion angle calculation step S3 of calculating a torsion angle ? per unit length of the optical fiber ribbon F on the basis of a difference ?? in strain amount between an outer core wire and an inner core wire; a torsional strain amount calculation step S4 of calculating a strain amount ?n caused by torsion of each core wire of the optical fiber ribbon F on the basis of the torsion angle ?; and a tensile strain amount calculation step S5 of subtracting the strain amount ?n from the strain amount ?n?, and calculating a strain amount ??n caused by tension of each core wire of the optical fiber ribbon F.

Abstract: The present disclosure relates to a frequency modulation amount measuring device that measures an optical spectral shift of scattered light at a position in an optical transmission line, and calculates a frequency modulation amount at the position, using the measured optical spectral shift.

Abstract: An object of the present invention is to provide an optical fiber measurement system, an optical fiber measurement method, a control calculation device, and a program that are capable of measuring loss and XT occurring at a plurality of points of an optical fiber in which a plurality of modes propagate, for each point.

Abstract: An object of the present disclosure is to provide a frequency division multiplexing coherent OTDR, a test method, a signal processing apparatus, and a program that can maintain, even in a case where a DFB laser is used, a spatial resolution equivalent to a spatial resolution achieved when a fiber laser or an external resonant laser is used.

Abstract: An object of the present invention is to provide an optical pulse test apparatus that can test an optical fiber cable at once in a short period of time.

Abstract: An object of the present disclosure is to provide an optical fiber cable monitoring method and an optical fiber cable monitoring system capable of linking information obtained from a measurement result with information stored in a DB and accurately specifying a loss occurrence location on an optical fiber cable. The optical fiber cable monitoring method according to the present disclosure uses two types of optical fiber measurement techniques having different sensitivities. Each of closure locations on the optical fiber cable is acquired with a high-sensitivity measurement technique, and geographical location information and the closure locations on the optical fiber are linked in an arrangement order of the closures. Thus, an operator can recognize an actual location (geographical location information) of a closure that is linked to a location of a point of abnormality on the optical fiber cable when an abnormality in the closure is detected with a low-sensitivity measurement technique.

Abstract: An object of the present disclosure is to provide a frequency division multiplexing coherent OTDR, a test method, a signal processing apparatus, and a program that can maintain, even in a case where a DFB laser is used, a spatial resolution equivalent to a spatial resolution achieved when a fiber laser or an external resonant laser is used.

Abstract: An object of the present invention is to provide an optical pulse test apparatus that can test an optical fiber cable at once in a short period of time.

Abstract: An object of the present disclosure is to provide an optical fiber cable monitoring method and an optical fiber cable monitoring system capable of linking information obtained from a measurement result with information stored in a DB and accurately specifying a loss occurrence location on an optical fiber cable. The optical fiber cable monitoring method according to the present disclosure uses two types of optical fiber measurement techniques having different sensitivities. Each of closure locations on the optical fiber cable is acquired with a high-sensitivity measurement technique, and geographical location information and the closure locations on the optical fiber are linked in an arrangement order of the closures. Thus, an operator can recognize an actual location (geographical location information) of a closure that is linked to a location of a point of abnormality on the optical fiber cable when an abnormality in the closure is detected with a low-sensitivity measurement technique.

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: 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: An object of the invention is to provide an optical reflectometry and an optical reflectometer, in which accurate measurement can be performed irrespective of a measurement distance. In the optical reflectometry and optical reflectometer according to the invention, in which a distribution of backscattered light intensity from a measurement target in an optical propagation direction is measured using Optical Frequency Domain Reflectometry (OFDR), a coherence monitor unit 12 that monitors a coherence property of a frequency sweep light source 1 is provided, and measurement result of a measuring unit 11 is corrected based on the monitor result of the coherence monitor unit 12.

Abstract: An object of the invention is to provide an optical reflectometry and an optical reflectometer, in which accurate measurement can be performed irrespective of a measurement distance. In the optical reflectometry and optical reflectometer according to the invention, in which a distribution of backscattered light intensity from a measurement target in an optical propagation direction is measured using Optical Frequency Domain Reflectometry (OFDR), a coherence monitor unit 12 that monitors a coherence property of a frequency sweep light source 1 is provided, and measurement result of a measuring unit 11 is corrected based on the monitor result of the coherence monitor unit 12.