US 12,111,493 B2
Optical connection structure and method for manufacturing the same
Yohei Saito, Tokyo (JP); Kota Shikama, Tokyo (JP); and Atsushi Aratake, Tokyo (JP)
Assigned to Nippon Telegraph and Telephone Corporation, Tokyo (JP)
Appl. No. 17/630,042
Filed by Nippon Telegraph and Telephone Corporation, Tokyo (JP)
PCT Filed Aug. 16, 2019, PCT No. PCT/JP2019/032141
§ 371(c)(1), (2) Date Jan. 25, 2022,
PCT Pub. No. WO2021/033217, PCT Pub. Date Feb. 25, 2021.
Prior Publication US 2022/0276436 A1, Sep. 1, 2022
Int. Cl. G02B 6/42 (2006.01); G02B 6/122 (2006.01)
CPC G02B 6/1221 (2013.01) [G02B 6/4212 (2013.01)] 15 Claims
OG exemplary drawing
 
1. An optical connection structure comprising:
a first optical waveguide;
a second optical waveguide having an end surface disposed to face an end surface of the first optical waveguide, and the second optical waveguide having a core diameter different from a core diameter of the first optical waveguide;
a holding member configured to secure the first optical waveguide and the second optical waveguide, wherein the holding member comprises an insertion portion into which the first optical waveguide and the second optical waveguide are to be inserted;
a spacer comprising a film disposed at a center of the insertion portion between the end surface of the first optical waveguide and the end surface of the second optical waveguide to define an interval between the end surface of the first optical waveguide and the end surface of the second optical waveguide, wherein a bottom surface of the spacer is higher than a bottom surface of the first optical waveguide and a bottom surface of the second optical waveguide in a cross-sectional view; and
a connection optical waveguide disposed between the end surface of the first optical waveguide and the end surface of the second optical waveguide to optically connect the first optical waveguide to the second optical waveguide, the connection optical waveguide including a resin core comprising a photo-curable resin, wherein a core diameter of the resin core gradually changes from a state adapted to the core diameter of the first optical waveguide to a state adapted to the core diameter of the second optical waveguide from a side facing the first optical waveguide to a side facing the second optical waveguide.