Light diffraction return type optical waveguide

The invention discloses a light diffraction return type optical waveguide, and particularly relates to the technical field of AR display, the light diffraction return type optical waveguide comprises a diffraction optical waveguide, the diffraction optical waveguide comprises at least one coupling-in area, at least one coupling-out area, at least one return area and at least one optical waveguide substrate material, the coupling-in area, the coupling-out area and the return area are located on the same side of the optical waveguide substrate material, and the coupling-in area, the coupling-out area and the return area are located on the same side of the optical waveguide substrate material. The coupling-out area is located between the coupling-in area and the returning area, the coupling-in area, the coupling-out area and the returning area are provided with a coupling-in grating, a coupling-out grating and a returning grating respectively, the coupling-in grating is arranged in an inclined groove shape, the