Patent attributes
A diffractive optical waveguide and a display apparatus are disclosed. A coupling-out grating includes a first grating having a first, second, and third grating vectors, directions of the second and third grating vectors, being respectively towards both sides of a direction of first grating vector, form acute angles with it, a cross-section profile of an optical unit structure of the first grating has a first, second, third, and fourth vertices, a straight line passing through the first and second vertices and a straight line passing through the third and fourth vertices are perpendicular to the direction, a straight line passing through the first and fourth vertices and a straight line passing through the second and third vertices respectively form angles θ
