US 12,013,571 B2
Optical connection device
Yuki Arao, Osaka (JP); Tetsuya Hayashi, Osaka (JP); and Tetsuya Nakanishi, Osaka (JP)
Assigned to SUMITOMO ELECTRIC INDUSTRIES, LTD., Osaka (JP)
Appl. No. 17/756,197
Filed by SUMITOMO ELECTRIC INDUSTRIES, LTD., Osaka (JP)
PCT Filed Nov. 27, 2020, PCT No. PCT/JP2020/044329
§ 371(c)(1), (2) Date May 19, 2022,
PCT Pub. No. WO2021/112016, PCT Pub. Date Jun. 10, 2021.
Claims priority of application No. 2019-219055 (JP), filed on Dec. 3, 2019.
Prior Publication US 2022/0413221 A1, Dec. 29, 2022
Int. Cl. G02B 6/26 (2006.01)
CPC G02B 6/262 (2013.01) 5 Claims
OG exemplary drawing
 
1. An optical connection device that has a structure for enabling optical connection of a single-core fiber which is included in a multi-core fiber and has a mode filed diameter of 8.6 μm or more and 9.2 μm or less with each of a plurality of cores each having a mode field of 8.6 μm or more and 9.2 μm or less, the optical connection device comprising:
a plurality of relay fibers that are provided in one-to-one correspondence with the plurality of cores of the multi-core fiber, each have a first core having a first relative refractive index difference Δ1(%) with pure silica as a reference, a second core surrounding an outer periphery of the first core and having a second relative refractive index difference Δ2(%) lower than the first relative refractive index difference Δ1(%), and a cladding surrounding an outer periphery of the second core and having a third relative refractive index difference Δ3(%) lower than the second relative refractive index difference Δ2, and have a first end face and a second end face opposite to the first end face; and
a capillary that has a third end face from which the first end face protrudes, and a fourth end face on which the second end face is disposed, and integrally holds each of the plurality of relay fibers extending from the third end face toward the fourth end face, wherein
the capillary includes a tapered portion that is provided between the third end face and the fourth end face and has an outer diameter ratio R of 0.2 or less defined by a ratio of an outer diameter of the fourth end face to an outer diameter of the third end face, and
in each of the plurality of relay fibers,
a refractive index volume V1(% μm2) given by a product ((π·r1b2)× (Δ1−Δ2)) of a cross-sectional area of the fourth end face defined by a radius r1b (μm) of the first core and a difference (Δ1−Δ2) between the first and second relative refractive index differences and a refractive index volume V2(% μm2) given by a product ((π·r2b2)×(Δ2−Δ3)) of a cross-sectional area of the fourth end face defined by a radius r2b (μm) of the second core and a difference (Δ2−Δ3) between the second and third relative refractive index differences satisfy a following Formula:
156%μm2≤(V2−V1)/R≤177%μm2.