Fujikura Limited

Hokkaido University

Hitoshi Uemura

Kunimasa Saitoh

Katsuhiro Takenaga

Yusuke Sasaki

Takeshi Fujisawa

Kensuke Ogawa

Hiroyuki Kusaka

Kazuhiro Goi

Ryokichi Matsumoto

Koji Omichi

Norihiro Ishikura

Kenichi Ohmori

Kenji Oda

Hiroki Ishihara

Provided is a method of manufacturing an optical device that includes a multicore fiber including a plurality of cores and a fan-in/fan-out device including single-core fibers that are respectively connected to the cores based on a plurality of connection combinations when the multicore fiber is rotated. The method includes: a first step of determining an optical loss for each of the cores while changing the connection combinations between the single-core fibers and the cores; and a second step of selecting one of the connection combinations according to a result of the first step and connecting an end portion of the multicore fiber and an end portion of the fan-in/fan-out device to connect the single-core fibers with the cores based on the one of the connection combinations.

Method for manufacturing optical device

A multicore fiber includes: a first core configured to propagate an LPmode, an LPmode, and an LPmode light beam; and a second core configured to propagate an LPmode light beam, wherein a different mode interaction section is provided in which a propagation constant of the LPmode light beam propagated through the first core is matched with a propagation constant of the LPmode light beam propagated through the second core, a different mode non-interaction section is provided in which propagation constants of the LP mode light beams propagated through the first core are not matched with propagation constants of the LP mode light beams propagated through the second core, and 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.

Multicore fiber

A multicore fiber includes: a center core that propagates four LP mode light beams including an LPmode light beam; and a first to a fifth cores disposed on a first line to a fifth line segments extend from the center of the center core in the radial direction at predetermined angles. The multicore fiber includes a different mode interaction section in which the propagation constants of each mode light beam propagated through the center core are matched with the propagation constants of LPmode light beams propagated through the first to fifth cores.

An optical modulation device configured of a planar optical waveguide, includes: a light incidence unit which allows light to be incident on the planar optical waveguide; a Mach-Zehnder interferometer which includes a first optical splitter section branching the light incident on the light incidence unit, two arm portions guiding the light branched by the first optical splitter section, a phase modulation unit linearly disposed on each of the two arm portions, and a first optical coupler section combining the light guided from the two arm portions; a light launching unit which launches the light combined by the first optical coupler section from the planar optical waveguide; and a traveling-wave electrode which includes an input unit and an output unit, and applies a voltage to the phase modulation unit.

Optical modulation device

A multicore fiberincludes: a small diameter portionin which a propagation constant of light of an x-th order LP mode of the first core(here, xis an integer of '2' or more and x or less, x is an integer of '2' or more) and a propagation constant of light of a y1-th order LP mode of the second core(here, yis an integer of &#x201c;1&#x201d; or more and y or less other than x, y is an integer of &#x201c;1&#x201d; or more) coincide with each other and a large diameter portion in which a propagation constant of light of each LP mode of the first coreand a propagation constant of light of each LP mode of the second coreare configured not to coincide with each other are arranged.

Multicore fiber with different-mode interaction section

An optical device includes: multiple cores each including an inner core and an outer core surrounding an outer circumferential surface of the inner core without any gap therebetween; and cladding surrounding an outer circumferential surface of the cores without any gap therebetween and having a refractive index lower than that of the outer core, wherein each of the cores has a tapered portion that is tapered from one side toward the other side thereof in a longitudinal direction, each of the inner cores includes a low-refractive-index portion, and a high-refractive-index portion surrounding an outer circumferential surface of the low-refractive-index portion without any gap therebetween and having a refractive index higher than that of the low-refractive-index portion, and the outer core has a refractive index lower than that of the high-refractive-index portion.

Optical device

0.5377&#xd7;r&#x2212;7.7&#x2266;V/V&#x2266;0.5377&#xd7;r&#x2212;5.7, 3&#x2266;r/r&#x2266;5 are satisfied, where a radius of the inner core before tapered in diameter is defined as r, a radius of the outer core before tapered in diameter is defined as r, a refractive index volume formed of a product of a cross sectional area of the inner core and a relative refractive index difference of the inner core to the cladding before tapered in diameter is defined as V, and a refractive index volume formed of a product of a cross sectional area of the outer core and a relative refractive index difference of the outer core to the cladding before tapered in diameter is defined as V.

A fan-in/fan-out device includes a plurality of single-core fibers which are connected to a plurality of first cores of a multicore fiber and which include an elongated portion extending in a longitudinal direction so as to reduce a diameter and being connected to a first end portion of the multicore fiber at a second end portion in an extending direction of the elongated portion, where a refractive index distribution of each of the single-core fibers has a single peak, a relative refractive index difference of a second core with respect to a second cladding in each of the single-core fibers is 0.8% or more; and a second mode field diameter of the second end portion of the elongated portion is greater than a first mode field diameter of the first end portion of the multicore fiber.

Growing community of inventors

Sakura, Japan

Hitoshi Uemura