Holographically displaying three-dimensional objects

A system, comprising:

• a display;
• and
• an optical device comprising:
• an optical guiding device configured to guide light to propagate along a first direction within the optical guiding device, the light comprising 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 towards the display,
• wherein each of the plurality of out-coupling diffractive structures comprises:
• multiple optically diffractive components respectively for the multiple colors of light;
• and
• one or more color-selective polarizers configured to rotate a polarization state of one or more colors of the multiple colors of light such that each color of light is diffracted out by a corresponding optically diffractive component along the second direction.

A system, comprising:

• a display;
• and
• an optical device comprising:
• an optical guiding device configured to guide light to propagate along a first direction within the optical guiding device, the light comprising 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 toward the display,
• wherein each of the plurality of out-coupling diffractive structures comprises:
• multiple optically diffractive components respectively for the multiple colors of light;
• and
• one or more reflective layers configured to totally reflect a single color of light and transmit one or more other colors of light such that each color of light is diffracted out by a corresponding optically diffractive component along the second direction.

A method, comprising:

• diffracting, by an in-coupling diffractive structure, light to propagate in an optical guiding device, the light comprising multiple colors of light;
• guiding the light to propagate along a first direction within the optical guiding device;
• and
• diffracting, by each of a plurality of out-coupling diffractive structures arranged downstream of the in-coupling diffractive structure along the first direction, at least part of the light out of the optical guiding device along a second direction different from the first direction towards a display,
• wherein diffracting the at least part of the light out of the optical guiding device comprises:
• separating the multiple colors of light from each other while suppressing crosstalk between the multiple colors of light.