An apparatus for optical aperture expansion of a light produced by a display source towards an eye of an observer, the apparatus comprising: - a lightguide having a pair of mutually-parallel major surfaces; - a non-diffractive input coupler configured to directly couple the light produced by the display source into the lightguide so as to propagate within the lightguide in an input direction by internal reflection at the major surfaces; - a set of three optical components associated with said lightguide, said set including: - a pair of first and second matching diffractive optical components (502, 50); and - a reflective optical component including a sequence of a plurality of partially reflective, mutually parallel surfaces angled obliquely to the major surfaces of the lightguide; - wherein the pair of first and second matching diffractive optical components (502, 50) forms a diffractive arrangement integrated with the lightguide and is configured to diffract the light propagating within the lightguide in the input direction through a first diffraction that redirects the light so as to propagate within the lightguide in a first direction non-parallel to the input direction by internal reflection at the major surfaces, and through a second diffraction which progressively redirects the light propagating within the lightguide in the first direction so as to propagate within the lightguide by internal reflection at the major surfaces in a second direction parallel to the input direction while expanding the light in the first direction, wherein the second diffractive optical component diffracts light in a compensatory fashion to the first diffractive component, such as to cancel the dispersion introduced by the first diffractive component; and - wherein the reflective optical component forms an output coupler progressively coupling the light expanded in the first direction by the diffractive arrangement out of the lightguide towards the eye of the observer while expanding the light in the second direction. - a lightguide having a pair of mutually-parallel major surfaces; - a non-diffractive input coupler configured to directly couple the light produced by the display source into the lightguide so as to propagate within the lightguide in an input direction by internal reflection at the major surfaces; - a set of three optical components associated with said lightguide, said set including: - a pair of first and second matching diffractive optical components (502, 50); and - a reflective optical component including a sequence of a plurality of partially reflective, mutually parallel surfaces angled obliquely to the major surfaces of the lightguide; - a pair of first and second matching diffractive optical components (502, 50); and - a reflective optical component including a sequence of a plurality of partially reflective, mutually parallel surfaces angled obliquely to the major surfaces of the lightguide; - wherein the pair of first and second matching diffractive optical components (502, 50) forms a diffractive arrangement integrated with the lightguide and is configured to diffract the light propagating within the lightguide in the input direction through a first diffraction that redirects the light so as to propagate within the lightguide in a first direction non-parallel to the input direction by internal reflection at the major surfaces, and through a second diffraction which progressively redirects the light propagating within the lightguide in the first direction so as to propagate within the lightguide by internal reflection at the major surfaces in a second direction parallel to the input direction while expanding the light in the first direction, wherein the second diffractive optical component diffracts light in a compensatory fashion to the first diffractive component, such as to cancel the dispersion introduced by the first diffractive component; and - wherein the reflective optical component forms an output coupler progressively coupling the light expanded in the first direction by the diffractive arrangement out of the lightguide towards the eye of the observer while expanding the light in the second direction.