Device for augmented reality or virtual reality display

Abstract

A device is disclosed comprising a waveguide (), an input diffractive optical structure () configured to receive light from a projector and couple the received light into the waveguide and an output diffractive optical structure (). An intermediate diffractive optical structure () is configured to receive light from the input diffractive optical structure (), provide a one-dimensional expansion of the received light, and couple the expanded light towards the output diffractive optical structure (). The output diffractive optical structure () is configured to receive light from the intermediate diffractive optical structure and couple it towards a viewer. The intermediate diffractive optical structure () comprises diffractive features that are oriented at a first angle to light received from the input diffractive optical structure to provide a first diffraction and a second diffraction within the intermediate diffractive optical structure in order to couple light towards the output diffractive optical structure. The first diffraction couples light from the input diffractive optical structure towards the diffractive features at a second angle so that the second diffraction is provided at a plurality of spaced positions in the intermediate diffractive optical structure thereby providing the one-dimensional expansion of light. The second diffraction couples light towards the output diffractive optical structure.