Holographically displaying three-dimensional objects with optical devices having in-coupling and out-coupling diffractive structures
Methods, apparatus, devices, subsystems, and systems for holographically displaying three-dimensional objects are provided. In one aspect, a device includes: an optical guiding device configured to guide light to propagate along a first direction within the optical guiding device, an in-coupling diffractive structure configured to diffract the light to propagate in the optical guiding device, and one or more out-coupling diffractive structures arranged downstream 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, different direction. The in-coupling diffractive structure is configured to cause a first optical dispersion for the light, and at least one out-coupling diffractive structure is configured to cause a second optical dispersion for the light. The first and second optical dispersions are compensated, such that light diffracted out of the optical guiding device has no or little optical dispersion.
1. A device, comprising:
an optical guiding device configured to guide light to propagate along a first direction within the optical guiding device, the light having a spectral bandwidth with a peak wavelength;
an in-coupling diffractive structure configured to diffract the light to propagate in the optical guiding device; and
one or more out-coupling diffractive structures arranged downstream 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,
wherein the in-coupling diffractive structure is configured to cause a first optical dispersion for the light, and at least one of the one or more out-coupling diffractive structures is configured to cause a second optical dispersion for the light, and wherein the first optical dispersion and the second optical dispersion are compensated with each other, such that light diffracted out of the optical guiding device has no or little optical dispersion, and
wherein the in-coupling diffractive structure comprises a first diffraction grating, and the at least one of the one or more out-coupling diffractive structures comprises a second diffraction grating, and wherein the first diffraction grating and the second diffraction grating are configured to cause the first optical dispersion and the second optical dispersion to be opposite dispersions having a same magnitude for the light.
2. The device of claim 1 , wherein the first diffraction grating has first fringe planes with a first fringe tilt angle, and the second diffraction grating has second fringe planes with a second fringe tilt angle, and wherein the first fringe tilt angle and the second fringe tilt angle have a same value with opposite directions, and
wherein the first diffraction grating has a first fringe spacing perpendicular to the first fringe planes, and the second diffraction grating has a second fringe spacing perpendicular to the second fringe planes, and wherein the first fringe spacing is identical to the second fringe spacing.
3. The device of claim 1 , wherein light diffracted by the first diffraction grating has a first beam width, and light diffracted by the second diffraction grating has a second beam width, and
wherein the first beam width and the second beam width are identical.
4. The device of claim 1 , wherein a first diffraction efficiency of the first diffraction grating for light with the peak wavelength is greater than a second diffraction efficiency of the second diffraction grating for the light with the peak wavelength.
5. The device of claim 1 , wherein the first diffraction grating is a reflection grating or a transmission grating, and
wherein the second diffraction grating is a reflection grating or a transmission grating.
6. The device of claim 1 , wherein the in-coupling diffractive structure is arranged in or on the optical guiding device, and wherein the one or more out-coupling diffractive structures comprise a plurality of out-coupling diffractive structures arranged in or on the optical guiding device along the first direction.
7. The device of claim 6 , wherein the plurality of out-coupling diffractive structures are in contact with or overlap with one another along the first direction, and wherein the in-coupling diffractive structure is spaced from the plurality of out-coupling diffractive structures.
8. The device of claim 6 , wherein, along the first direction, a width of the in-coupling diffractive structure is identical to a width of each of the plurality of out-coupling diffractive structures.
9. The device of claim 6 , wherein the in-coupling diffractive structure comprises a first diffraction grating, and each of the plurality of out-coupling diffractive structures comprises a respective second diffraction grating, and
wherein the first diffraction grating and the respective second diffraction grating are configured to cause opposite dispersions having a same magnitude for the light.
10. The device of claim 6 , wherein the plurality of out-coupling diffractive structures comprise a first out-coupling diffractive structure and a second output-coupling diffractive structure that is arranged farther away from the in-coupling diffractive structure than the first out-coupling diffractive structure, and
wherein the second output-coupling diffractive structure has a higher diffraction efficiency for light with the peak wavelength than the first output-coupling diffractive structure.
11. The device of claim 10 , wherein the first out-coupling diffractive structure is configured to diffract a first portion of the light incident on the first out-coupling diffractive structure out of the optical guiding device, the diffracted first portion of the light having a first optical power,
wherein the second out-coupling diffractive structure is configured to diffract a second portion of the light incident on the second out-coupling diffractive structure out of the optical guiding device, the diffracted second portion of the light having a second optical power, and
wherein the first portion of the light has a higher optical power than the second portion of the light, and the first out-coupling structure and the second out-coupling structure are configured such that the second optical power is identical to the first optical power.
12. The device of claim 6 , wherein the diffracted light from the in-coupling diffractive structure propagates via total internal reflection in the optical guiding device along the first direction to be sequentially incident on each of the plurality of out-coupling diffractive structures along the first direction, and
wherein the plurality of out-coupling diffractive structures are configured to have gradually increased diffraction efficiencies for the light along the first direction, such that diffracted light by each of the plurality of out-coupling diffractive structures out of the optical guiding device has a same optical power.
13. The device of claim 12 , wherein the diffracted light from the in-coupling diffractive structure is incident on each of the plurality of out-coupling diffractive structures with a same incident angle, and
wherein each of the plurality of out-coupling diffractive structures is configured such that the diffracted light by each of the plurality of out-coupling diffractive structures has a same diffraction angle.
14. The device of claim 1 , wherein the light comprises light with different colors, and
wherein the in-coupling diffractive structure comprises a first corresponding diffraction grating for light with each of the different colors, and
wherein each of the one or more out-coupling diffractive structures comprises a second corresponding diffraction grating for the light with each of the different colors.
15. The device of claim 14 , wherein the first corresponding diffraction gratings for the light with the different colors are recorded in a same first recording medium, or
the second corresponding diffraction gratings for the light with the different colors are recorded in a same second recording medium, or
wherein each of the first corresponding diffraction gratings for the light with the different colors is recorded in a respective first recording medium, or
wherein each of the second corresponding diffraction gratings for the light with the different colors is recorded in a respective second recording medium.
16. 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 having a spectral bandwidth with a peak wavelength;
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 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 that is different from the first direction,
wherein the in-coupling diffractive structure is configured to cause a first optical dispersion for the light, and each of the plurality of out-coupling diffractive structures is configured to cause a second optical dispersion for the light, and wherein the first optical dispersion and the second optical dispersion are compensated with each other, such that light diffracted out of the optical guiding device has no or little optical dispersion, and
wherein the in-coupling diffractive structure comprises a first diffraction grating, and each of the plurality of out-coupling diffractive structures comprises a respective second diffraction grating, and wherein the first diffraction grating and the respective second diffraction grating are configured to cause opposite dispersions having a same magnitude for the light.
17. The system of claim 16 , wherein each of the first diffraction grating and the respective second diffraction grating is a reflection grating.
18. The system of claim 16 , wherein the diffracted light from the in-coupling diffractive structure propagates via total internal reflection in the optical guiding device along the first direction to be sequentially incident on each of the plurality of out-coupling diffractive structures along the first direction, and
wherein the plurality of out-coupling diffractive structures are configured to have gradually increased diffraction efficiencies for the light along the first direction, such that diffracted light by each of the plurality of out-coupling diffractive structures out of the optical guiding device has a same optical power.
19. The system of claim 18 , wherein the plurality of out-coupling diffractive structures are configured such that the diffracted light by each of the plurality of out-coupling diffractive structures propagates to illuminate a respective portion of the display, a sum of the respective portions of the display being no smaller than an area of the display.
20. The system of claim 16 , wherein the in-coupling diffractive structure is configured to receive the light at a first incident angle and diffract the light at a first diffraction angle, and
wherein each of the plurality of out-coupling diffractive structures is configured to receive reflected light from the optical guiding device at a second incident angle and diffract the reflected light at a second diffraction angle,
wherein the first incident angle is identical to the second diffraction angle, and the first diffraction angle is identical to the second incident angle.
21. The system of claim 16 , wherein the display comprises a plurality of display elements extending along the first direction and a third direction perpendicular to the first direction and the second direction,
wherein the optical guiding device is a first optical guiding device, the in-coupling diffractive structure is a first in-coupling diffractive structure, and the plurality of out-coupling diffractive structures is a plurality of first out-coupling diffractive structures, and
wherein the system further comprises:
a second optical guiding device extending along the first direction and the third direction,
a plurality of second in-coupling diffractive structures arranged in or on the second optical guiding device along the first direction, and
multiple groups of second out-coupling diffractive structures, each group of second out-coupling diffractive structures being arranged in or on the second optical guiding device along the third direction,
wherein, for each of the plurality of second in-coupling diffractive structures,
the second in-coupling diffractive structure is configured to receive first light diffracted from a respective first out-coupling diffractive structure and diffract the first light to propagate in the second optical guiding device via TIR along the third direction to be sequentially incident on a corresponding group of second out-coupling diffractive structures, and
each of the corresponding group of second out-coupling diffractive structures is configured to receive second light reflected from the second optical guiding device and diffract the second light out of the second optical guiding device towards the display along the second direction.
22. The system of claim 21 , wherein the second in-coupling diffractive structure has a higher diffraction efficiency than the respective first out-coupling diffractive structure and each of the corresponding group of second out-coupling diffractive structures,
wherein the second in-coupling diffractive structure comprises a first diffraction grating, and each of the corresponding group of second out-coupling diffractive structures comprises a respective second diffraction grating, and
wherein the first diffraction grating and the respective second diffraction grating are configured to cause opposite dispersions having a same magnitude for the light.
23. The system of claim 21 , wherein the first in-coupling diffractive structure, the plurality of first out-coupling diffractive structures, the plurality of second in-coupling diffractive structures, and the multiple groups of second out-coupling diffractive structures are configured such that diffracted light from each of the multiple groups of second out-coupling diffractive structures along the second direction towards the display has a uniform optical power.
24. The system of claim 21 , wherein the multiple groups of second out-coupling diffractive structures are configured such that the diffracted light by each of the multiple groups of second out-coupling diffractive structures propagates to illuminate a respective portion of the display, a sum of the respective portions of the display being no smaller than an area of the display.
25. The system of claim 16 , wherein the light comprises light with different colors, and wherein the in-coupling diffractive structure comprises a corresponding first diffraction grating for light with each of the different colors, and
wherein each of the plurality of out-coupling diffractive structures comprises a corresponding second diffraction grating for light with each of the different colors.
26. The system of claim 16 , wherein the display comprises:
a backplane comprising a plurality of circuits; and
a plurality of display elements arranged on the backplane, the plurality of display elements forming an irregular pattern, wherein each of the plurality of display elements is coupled to a respective circuit of the plurality of circuits; and
wherein the system further comprises:
an illuminator configured to emit the light; and
a controller coupled to the display and the illuminator,
wherein the controller is configured to:
transmit at least one control signal to at least one display element of the display for modulating at least one property of the at least one display element,
sequentially modulate the display with information associated with a first color during a first time period and modulate the display with information associated with a second color during a second, sequential time period; and
control the illuminator to sequentially turn on a first light emitting element to emit light with the first color during the first time period and a second light emitting element to emit light with the second color during the second, sequential time period.
27. An optical device comprising:
a first optical guiding device configured to guide light to propagate along a first direction within the first optical guiding device via total internal reflection, the light having a spectral bandwidth with a peak wavelength;
a first in-coupling diffractive structure configured to diffract the light to propagate in the first optical guiding device;
a first plurality of out-coupling diffractive structures arranged downstream the first in-coupling diffractive structure along the first direction and configured to diffract at least part of the light out of the first optical guiding device along a second direction that is different from the first direction;
a second optical guiding device extending along the first direction and a third direction perpendicular to the first direction and the second direction;
a plurality of second in-coupling diffractive structures arranged in or on the second optical guiding device along the first direction;
multiple groups of second out-coupling diffractive structures, each group of second out-coupling diffractive structures being arranged in or on the second optical guiding device along the third direction,
wherein the first in-coupling diffractive structure is configured to cause a first optical dispersion for the light, and each of the plurality of first out-coupling diffractive structures is configured to cause a second optical dispersion for the light, and wherein the first optical dispersion and the second optical dispersion are compensated with each other, such that light diffracted out of the first optical guiding device has no or little optical dispersion, and
wherein, for each of the plurality of second in-coupling diffractive structures,
the second in-coupling diffractive structure is configured to receive first light diffracted from a respective first out-coupling diffractive structure and diffract the first light to propagate in the second optical guiding device via total internal reflection along the third direction to be sequentially incident on a corresponding group of second out-coupling diffractive structures,
each of the corresponding group of second out-coupling diffractive structures is configured to receive second light reflected from the second optical guiding device and diffract the second light out of the second optical guiding device along the second direction, and
wherein the second in-coupling diffractive structure and each of the corresponding group of second out-coupling diffractive structures are configured to cause opposite dispersions to compensate with each other, such that light diffracted out of the second optical guiding device has no or little optical dispersion.
28. The optical device of claim 27 , wherein the first in-coupling diffractive structure, the plurality of first out-coupling diffractive structures, the plurality of second in-coupling diffractive structures, and the multiple groups of second out-coupling diffractive structures are configured such that diffracted light from each of the multiple groups of second out-coupling diffractive structures along the second direction towards has a uniform optical power.
29. A device, comprising:
an optical guiding device configured to guide light to propagate along a first direction within the optical guiding device, the light having a spectral bandwidth with a peak wavelength;
an in-coupling diffractive structure configured to diffract the light to propagate in the optical guiding device; and
one or more out-coupling diffractive structures arranged downstream 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,
wherein the in-coupling diffractive structure is configured to cause a first optical dispersion for the light, and at least one of the one or more out-coupling diffractive structures is configured to cause a second optical dispersion for the light, and wherein the first optical dispersion and the second optical dispersion are compensated with each other, such that light diffracted out of the optical guiding device has no or little optical dispersion,
wherein the in-coupling diffractive structure is arranged in or on the optical guiding device, and wherein the one or more out-coupling diffractive structures comprise a plurality of out-coupling diffractive structures arranged in or on the optical guiding device along the first direction, and
wherein the plurality of out-coupling diffractive structures comprise a first out-coupling diffractive structure and a second output-coupling diffractive structure that is arranged farther away from the in-coupling diffractive structure than the first out-coupling diffractive structure, and wherein the second output-coupling diffractive structure has a higher diffraction efficiency for light with the peak wavelength than the first output-coupling diffractive structure.
30. 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 having a spectral bandwidth with a peak wavelength;
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 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 that is different from the first direction,
wherein the in-coupling diffractive structure is configured to cause a first optical dispersion for the light, and each of the plurality of out-coupling diffractive structures is configured to cause a second optical dispersion for the light, and wherein the first optical dispersion and the second optical dispersion are compensated with each other, such that light diffracted out of the optical guiding device has no or little optical dispersion, and
wherein the in-coupling diffractive structure is configured to receive the light at a first incident angle and diffract the light at a first diffraction angle, wherein each of the plurality of out-coupling diffractive structures is configured to receive reflected light from the optical guiding device at a second incident angle and diffract the reflected light at a second diffraction angle, and wherein the first incident angle is identical to the second diffraction angle, and the first diffraction angle is identical to the second incident angle.
31. A system comprising:
a display comprising:
a backplane comprising a plurality of circuits; and
a plurality of display elements arranged on the backplane, the plurality of display elements forming an irregular pattern, wherein each of the plurality of display elements is coupled to a respective circuit of the plurality of circuits;
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 having a spectral bandwidth with a peak wavelength;
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 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 that is different from the first direction,
wherein the in-coupling diffractive structure is configured to cause a first optical dispersion for the light, and each of the plurality of out-coupling diffractive structures is configured to cause a second optical dispersion for the light, and wherein the first optical dispersion and the second optical dispersion are compensated with each other, such that light diffracted out of the optical guiding device has no or little optical dispersion;
an illuminator configured to emit the light; and
a controller coupled to the display and the illuminator,
wherein the controller is configured to:
transmit at least one control signal to at least one display element of the display for modulating at least one property of the at least one display element,
sequentially modulate the display with information associated with a first color during a first time period and modulate the display with information associated with a second color during a second, sequential time period; and
control the illuminator to sequentially turn on a first light emitting element to emit light with the first color during the first time period and a second light emitting element to emit light with the second color during the second, sequential time period.