Optical fan-in/fan-out device
AssigneesFujikura Ltd., National University Corporation Hokkaido University
InventorsShoichiro Matsuo, Katsuhiro Takenaga, Kunimasa Saitoh, Masanori Koshiba
Life of this patent
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Abstract
A radius of a first core 21 in a large-diameter end surface EF1 of a tapered portion 31 is denoted by r1S, a radius of a second core 22 is denoted by r2S, a relative refractive index difference of the first core 21 with respect to a clad 23 is denoted by Δ1, a relative refractive index difference of the second core 22 with respect to the clad 23 is denoted by Δ2, a refractive index volume of the first core 21 is denoted by V1S, and a refractive index volume of the second core 22 is denoted by V2S, r2S/r1S is set to be 3 or more and 5 or less, V2S/V1S is set to be 1.07r22−13.5 or more and 1.07r22−11.5 or less, and r2S/r1S is set to be −3×Δ1/Δ2+10 or more.
Claims3
An optical fan-in/fan-out device comprising:
- a plurality of relay fibers;
- and
- an outer circumference clad which is integrated with each of the plurality of relay fibers to fill a space between the relay fibers and to surround a circumference surface of each relay fiber,
- wherein the relay fiber includes:
- a first core;
- a second core which has a refractive index lower than a refractive index of the first core and surrounds a circumference surface of the first core without clearance;
- and
- a clad which has a refractive index lower than a refractive index of the second core and surrounds a circumference surface of the second core without clearance,
- the outer circumference clad has a tapered portion by which the plurality of relay fibers is shrunk in diameter from one end side toward the other end side, and
- in a case where a radius of the first core in a large-diameter end surface of the tapered portion is denoted by r1S, a radius of the second core in the large-diameter end surface is denoted by r2S, a relative refractive index difference of the first core with respect to the clad is denoted by Δ1, a relative refractive index difference of the second core with respect to the clad is denoted by Δ2, a refractive index volume of the first core expressed by r1S2×Δ1is denoted by V1S, and a refractive index volume of the second core expressed by π(r2S2−r1S2)×Δ2 is denoted by V2S, the following equation is satisfied;
- 3≦r2S/r1S≦5
- 1.07r2S−13.5≦V2S/V1S≦1.07r2S−11.5
- r2S/r1S≧3×Δ1/Δ2+10.
Dependencies are inferred from the claim text.