A holographic display apparatus for providing an expanded viewing window comprising: a light source configured to output light of different first, second, and third colors; a spatial light modulator configured to display a hologram pattern, said hologram pattern being formed by the spatial light modulator for diffracting and modulating the light incident from the light source, wherein the physical structure of the spatial light modulator comprises an array of a plurality of pixels thereby forming a lattice; and an optical system comprising means configured for focusing the light diffracted and modulated by the spatial light modulator so that a plurality of holographic images (L00, L01, L-01, L10, L-10), generated by a 0 th and higher order diffraction due to the hologram pattern displayed on the spatial light modulator, are reproduced, said optical system further comprising a spatial filter (133, 135) configured to allow the plurality of holographic images to be transmitted through the optical system, thereby expanding the viewing window, the spatial filter being further configured to filter, on a predetermined focal plane, the plurality of holographic images from a plurality of lattice spots (N0, N1) generated by diffraction of incident light by said lattice, wherein each of the plurality of holographic images comprises a first color image, a second color image, and a third color image, wherein each of the plurality of lattice spots comprises a first color lattice spot, a second color lattice spot, and a third color lattice spot, and wherein the spatial filter comprises a plurality of color filters (CF1, CF2, CF3, CF4, CF5, CF6) or a plurality of dichroic mirrors configured to respectively filter the first color images, the second color images, and the third color images from the first color lattice spots, the second color lattice spots, and the third color lattice spots. a light source configured to output light of different first, second, and third colors; a spatial light modulator configured to display a hologram pattern, said hologram pattern being formed by the spatial light modulator for diffracting and modulating the light incident from the light source, wherein the physical structure of the spatial light modulator comprises an array of a plurality of pixels thereby forming a lattice; and an optical system comprising means configured for focusing the light diffracted and modulated by the spatial light modulator so that a plurality of holographic images (L00, L01, L-01, L10, L-10), generated by a 0 th and higher order diffraction due to the hologram pattern displayed on the spatial light modulator, are reproduced, said optical system further comprising a spatial filter (133, 135) configured to allow the plurality of holographic images to be transmitted through the optical system, thereby expanding the viewing window, the spatial filter being further configured to filter, on a predetermined focal plane, the plurality of holographic images from a plurality of lattice spots (N0, N1) generated by diffraction of incident light by said lattice, wherein each of the plurality of holographic images comprises a first color image, a second color image, and a third color image, wherein each of the plurality of lattice spots comprises a first color lattice spot, a second color lattice spot, and a third color lattice spot, and wherein the spatial filter comprises a plurality of color filters (CF1, CF2, CF3, CF4, CF5, CF6) or a plurality of dichroic mirrors configured to respectively filter the first color images, the second color images, and the third color images from the first color lattice spots, the second color lattice spots, and the third color lattice spots.