Planar optical waveguide structure and coupling structure and coupling method thereof

The invention relates to the technical field of optical waveguide coupling and provides a planar optical waveguide structure and a coupling structure and a coupling method thereof. The planar optical waveguide structure comprises a single-mode active device and a planar optical waveguide, wherein the planar optical waveguide comprises a silicon dioxide waveguide for transmitting optical signals, the silicon dioxide waveguide is composed of a coupling section and a conduction section, the coupling section is of a trapezoidal structure or a reverse trapezoidal structure, the face, coupled with the single-mode active device, of the coupling section is a trapezoid top, and the face, connected with the conduction section, of the coupling section is a trapezoid bottom. A coupling spacing gap is preformed between the single-mode active device and the planar optical waveguide. Passive beam focusing and direct coupling from a laser device to PLC are completed by adopting the planar optical waveguide structure, the structure can be completed by adopting an automatic device, the process quality can be greatly ensured, the time for beam focusing and welding is shortened, and accordingly the purpose of reducing the costs is achieved.