US Patent 10209412 Display with multilayer diffractive optical elements

The display headset for presenting an image to a user includes an electronic display and an optics block. The electronic display emits image light associated with the image toward an exit pupil corresponding to a location of an eye of the user. The optics block directs the image light from the electronic display to the exit pupil. The optics block includes a first diffractive optical element between the exit pupil and the electronic display, a second diffractive optical element between the first diffractive optical element and the exit pupil, a first protective layer on the first diffractive optical element to protect the first diffractive optical element, and a second protective layer on the second diffractive optical element to protect the second diffractive optical element. The first protective layer and the second protective layer compensate for a variation in a diffraction efficiency at different wavelengths and incident angles of the light.