Nippon Telegraph and Telephone Corporation

Kazutaka Noto

Hiroyuki Oshida

Nazuki Honda

Atsushi Nakamura

Tetsuya Manabe

Yusuke Koshikiya

An object of the present invention is to provide an optical fiber test method, an optical fiber test apparatus, and a program, capable of detecting a boundary of an optical fiber line facility regardless of a change in a noise amount. A change amount (a differential value) of an OTDR waveform increases toward a distal end due to noise effects, making it difficult to determine a boundary of the optical fiber using the change amount. Therefore, in the present invention, a dispersion of the OTDR waveform, which increases toward a distal end due to noise effects, is also used to determine the boundary of the optical fiber. In other words, in the present invention, the noise amount is expressed by the dispersion, and the dispersion is compared with the change amount such as a differential value as a threshold, to determine the boundary of the optical fiber. For this reason, when noise increases, the threshold increases together with an increase in the change amount, and therefore, the boundary of the optical fiber can be determined regardless of noise.

Fiber optic test methods, fiber optic test equipment, and programs

An object of the present disclosure is to realize water immersion detection that does not require a replacement module, and does not cause any optical loss. The present disclosure relates to a device configured to measure guided acoustic wave Brillouin scattering in a measurement target optical fiber, and detect water immersion of the measurement target optical fiber based on a characteristic around a peak of the guided acoustic wave Brillouin scattering.

Water immersion detection device and water immersion detection method for detecting inundation of optical fiber

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.

Growing community of inventors

Musashino, Japan

Kazutaka Noto