Abstract: Disclosed herein is an optical device having a spatially-varying volume holographic grating (VHG), and methods, systems and apparatus for making the same. An optical device according to the disclosure has one or both of a spacing and a slant angle of the VHG which varies across locations of the optical device. A method for making an such an optical device includes: irradiating a photosensitive material with a first beam of light; producing a volume holographic grating in the photosensitive material by producing an interference pattern between the first beam with a second beam of light; moving the first beam and the second beam or the photosensitive material relative to the other to scan the first beam and the second beam across locations on the photosensitive material; and varying one or both of a spacing and a slant angle of the volume holographic grating across locations on the photosensitive material.