Planar optical waveguide structure, and coupling structure thereof and coupling method thereof
A coupling structure includes a single mode active device and a planar optical waveguide. Specifically, the planar optical waveguide includes a silica waveguide for transmitting an optical signal, where the silica waveguide includes a coupling section and a conduction section; the coupling section is of a regular trapezoidal structure or an inverted trapezoidal structure, where a surface of the coupling section coupled to the single mode active device is a trapezoid top, and a surface of the coupling section connected with the conduction section is a trapezoid bottom; and a coupling gap is preset between the single mode active device and the planar optical waveguide.
1. A planar optical waveguide structure, wherein
the planar optical waveguide internally comprises a silica main waveguide for transmitting an optical signal, and an auxiliary waveguide for assisting light entering;
the auxiliary waveguide comprises one or more silica auxiliary waveguides that are positioned at a predetermined center distance from the silica main waveguide;
wherein the auxiliary waveguide specifically comprises eight sub-auxiliary waveguides, wherein a first sub-auxiliary waveguide is located on an upper side of the silica main waveguide; a second sub-auxiliary waveguide is located on a lower side of the silica main waveguide; a third sub-auxiliary waveguide is located on a left side of the silica main waveguide; a fourth sub-auxiliary waveguide is located on a right side of the silica main waveguide; a fifth sub-auxiliary waveguide is located on an upper left side of the silica main waveguide, on a left side of the first sub-auxiliary waveguide, and on an upper side of the third sub-auxiliary waveguide; a sixth sub-auxiliary waveguide is located on an upper right side of the silica main waveguide, on the right side of the first sub-auxiliary waveguide, and on an upper side of the fourth sub-auxiliary waveguide; a seventh sub-auxiliary waveguide is located on a lower left side of the silica main waveguide, on a left side of the second sub-auxiliary waveguide, and on a lower side of the third sub-auxiliary waveguide; and an eighth sub-auxiliary waveguide is located on a lower right side of the silica main waveguide, on a right side of the second sub-auxiliary waveguide, and on a lower side of the fourth sub-auxiliary waveguide.
2. The planar optical waveguide structure according to claim 1 , wherein each sub-auxiliary waveguide is specifically of a regular trapezoidal structure, and four side faces connected with a trapezoid top and a trapezoid bottom are all inclined planes, wherein the trapezoid top and a light inlet of the silica main waveguide are located on a same side of a multi-core planar optical waveguide.