Methods, apparatus, devices, subsystems, and systems for holographically displaying three-dimensional objects are provided. In one aspect, an optical device includes: an optical guiding device configured to guide light to propagate along a first direction within the optical guiding device, the light including multiple colors of light; an in-
coupling diffractive structure configured to diffract the light to propagate in the optical guiding device; and a plurality of out-
coupling diffractive structures arranged downstream of the in-
coupling diffractive structure along the first direction and configured to diffract at least part of the light out of the optical guiding device along a second direction different from the first direction. The optical device can be configured for at least one of: color
crosstalk suppression among the multiple colors of light, display zero order light suppression,
dispersion compensation, or ambient light blocking.