Fujikura Limited

Hokkaido University

Shota Saito

Katsuhiro Takenaga

Kunimasa Saitoh

Takeshi Fujisawa

Yoshimichi Amma

An optical fiber that communicates in a predetermined communication band includes: a signal light propagation core that propagates light beams of up to (x+1)-th order LP mode, where x is an integer of two or more; and a coupler that propagates a light beam that is: coupled with a light beam of the (x+1)-th order LP mode propagating through the signal light propagation core, and suppressed from being coupled with light beams of up to the x-th order LP mode propagating through the signal light propagation core, wherein, mode coupling of the light beams of up to the x-th order LP mode propagating through the signal light propagation core is performed, and mode coupling between the light beam of the x-th order LP mode and the light beam of (x+1)-th order LP mode is suppressed.

Optical fiber

A characteristic-measuring apparatus for a multi-core fiber includes: a coupling device that couples, at a first end of the multi-core fiber, light to a plurality of cores in the multi-core fiber; an imaging device that takes an image, at a second end of the multi-core fiber, of emission light emitted from the plurality of cores, where the plurality of cores are imaged at the same time; and a calculating device that determines a characteristic of the multi-core fiber based on images obtained by the imaging device.

Characteristic-measuring apparatus and characteristic-measuring method for multi-core fiber

A method of measuring crosstalk of a multicore fiber, the method including capturing an emitted light pattern at an end portion of a dummy fiber and obtaining a correlation data between a power of the light incident on the dummy fiber and the emitted light pattern, irradiating one core of the multicore fiber with a light through the dummy fiber, and measuring a power of a reference light emitted from the core, capturing a crosstalk light emitted from a different core different from the core on which the light is incident under a state where the reference light is masked, and estimating a power of the crosstalk light from a captured data of the crosstalk light and the correlation data, and calculating the crosstalk from the power of the reference light and the power of the crosstalk light.

Method of measuring crosstalk of multicore fiber and apparatus of measuring the same

A multicore fiber that includes: three or more cores that transmit in single-mode transmission; a common clad that covers a periphery of the three or more cores; and a low-refractive index portion that has a refractive index lower than a refractive index of the clad. The multicore fiber further includes a region having the three or more cores arranged annularly on a cross-section perpendicular to a longitudinal direction. At least a portion of the low-refractive index portion is arranged inside a minimum inscribed circle of two adjacent cores within the region.

Multicore fiber and optical cable

A multicore fiber includes a plurality of cores including a first core and a cladding surrounding the plurality of cores. The first core includes: an inner core; and an outer core surrounding the inner core with no gap and having a refractive index higher than a refractive index of the inner core and a refractive index of the cladding. The core is not doped with any rare earth element. At least two LP mode light beams at a predetermined wavelength propagate through the first core at an attenuation of 0.3 dB/km or less.

Multicore fiber

A multicore fiber including two or more cores each capable of single mode transmission, a cladding covering around the two or more cores in common, and a low refractive index portion having a refractive index lower than a refractive index of the cladding, wherein a cross-section perpendicular to a longitudinal direction includes a region where two or more cores of a part or all of the two or more cores are arranged in a circular shape and at least a part of the low refractive index portion is arranged inside an inscribed circle of the cores included in the region.

Growing community of inventors

Sakura, Japan

Shota Saito