Abstract: Provided is an optical cable monitoring system for monitoring a health of optical cables including plural optical fibers. The system includes an optical power detector including a light power monitor, a failure determination unit and an alert signal generator, the light power monitor measuring light intensity of an extracted portion of communication light transmitted through each optical fiber and obtaining communication light intensity based on the measured light intensity, the failure determination unit determining presence of failure in each optical fiber based on the measurement result of the light power monitor, and the alert signal generator generating an alert signal when failure is determined to occur by the failure determination unit, and a monitoring device that receives an alert signal from the optical power detector.

Abstract: A communication light detection device includes a housing provided with plural first optical adapters and plural second optical adapters, and plural light detection portions provided in connection portions respectively for optically connecting together a first optical fiber provided in the housing and extended from the first optical adapters into the housing and a second optical fiber extended from the corresponding second optical adapters into the housing, to detect light transmitted via both the optical fibers. The light detection portions each include a light leak portion provided in the connection portions to allow light to partially leak, a light receiving element to detect the light leaked at the light leak portion, and a case including a recessed groove for accommodating the connection portions and not transmitting light. A circuit board is included with the light receiving elements mounted thereon together, and is provided to close openings of the recessed grooves together.

Abstract: A communication light detection device includes a housing provided with plural first optical adapters and plural second optical adapters, and plural light detection portions provided in connection portions respectively for optically connecting together a first optical fiber provided in the housing and extended from the first optical adapters into the housing and a second optical fiber extended from the corresponding second optical adapters into the housing, to detect light transmitted via both the optical fibers. The light detection portions each include a light leak portion provided in the connection portions to allow light to partially leak, a light receiving element to detect the light leaked at the light leak portion, and a case including a recessed groove for accommodating the connection portions and not transmitting light. A circuit board is included with the light receiving elements mounted thereon together, and is provided to close openings of the recessed grooves together.

Abstract: Provided is an optical cable monitoring system for monitoring a health of optical cables including plural optical fibers. The system includes an optical power detector including a light power monitor, a failure determination unit and an alert signal generator, the light power monitor measuring light intensity of an extracted portion of communication light transmitted through each optical fiber and obtaining communication light intensity based on the measured light intensity, the failure determination unit determining presence of failure in each optical fiber based on the measurement result of the light power monitor, and the alert signal generator generating an alert signal when failure is determined to occur by the failure determination unit, and a monitoring device that receives an alert signal from the optical power detector.

Abstract: An optical fiber monitoring system monitors an inter-building optical fiber connecting a first building and a second building. The optical fiber monitoring system includes a first visualization panel provided in the first building and optically connected to an one end of the inter-building optical fiber, a second visualization panel provided in the second building and optically connected to an other end of the inter-building optical fiber, and a monitoring light source provided in the first building to input a monitoring light into the inter-building optical fiber. The first visualization panel includes a first photosensor that partially leaks the monitoring light inputted into the inter-building optical fiber from the monitoring light source and detects an amount of a leaked light. The second visualization panel includes a second photosensor that partially leaks a light from the inter-building optical fiber and detects amount of a leaked light.

Abstract: An optical fiber monitoring system monitors an inter-building optical fiber connecting a first building and a second building. The optical fiber monitoring system includes a first visualization panel provided in the first building and optically connected to an one end of the inter-building optical fiber, a second visualization panel provided in the second building and optically connected to an other end of the inter-building optical fiber, and a monitoring light source provided in the first building to input a monitoring light into the inter-building optical fiber. The first visualization panel includes a first photosensor that partially leaks the monitoring light inputted into the inter-building optical fiber from the monitoring light source and detects an amount of a leaked light. The second visualization panel includes a second photosensor that partially leaks a light from the inter-building optical fiber and detects amount of a leaked light.

Abstract: An optical fiber vibration sensor includes a light source, an optical receiver, an optical dividing/coupling portion, a signal processing unit, and a fiber loop portion made of an optical fiber. A part of an optical fiber composing the fiber loop portion is installed inside a housing of a main body of the optical fiber vibration sensor as an optical fiber for delay and another part of the optical fiber composing the fiber loop portion is installed outside the housing as a vibration detecting optical fiber.

Abstract: An optical fiber vibration sensor includes a light source, an optical receiver, an optical dividing/coupling part, a signal processing unit, and a fiber loop part made of an optical fiber. A part of an optical fiber composing the fiber loop part is installed outside a housing of a main body of the optical fiber vibration sensor and another part of the optical fiber composing the fiber loop part is installed outside the housing as a vibration detecting optical fiber.

Abstract: Disclosed is an optical fiber gyroscope comprising a fiber coil composed of a lengthy optical fiber wound therearound in a predetermined number of turns, a coupler for optically coupling an optical fiber led from a light source and an optical fiber led to a photodetector, and an optical IC chip arranged between the fiber coil and the coupler and provided with a phase modulator and a polarizer mounted on an optical waveguide, the optical fiber gyroscope further comprising a fiber coil reel around which the lengthy optical fiber for constructing the fiber coil is wound in the predetermined number of turns, a coupler reel around which the optical fibers led in both directions from the coupler are wound in a predetermined number of turns, and a housing member including a plurality of compartments (reel-placing region, frame, frame) for accommodating at least the both reels, the light source, and the optical IC chip.

Abstract: In an optical fiber gyro for detecting a rotation angular velocity by Sagnac phase difference of light signals propagated through an optical fiber sensing loop, no polarizer is used, and a light source having a difference in attenuation or amplification factor between two orthogonally polarized lights is used. Alternatively, a light source is optically coupled to an optical coupler for supplying two divided light signals to the sensing loop and receiving the two light signals propagated through sensing loop by an optical fiber of a predetermined length which is set to meet a relation in which a distance difference determined by the predetermined length and a phase difference of two orthogonally polarized lights propagated through the optical fiber is greater than an interference distance of the light source.