Systems and methods for producing wide field-of-view holographic displays
View Patent ↗Hologram recording devices and techniques can be employed to produce wide field-of-view holograms. A lens can be used to couple an object beam into a holographic recording material without substantially changing the angle of incidence of the object beam. When displayed, images from holograms recorded using this technique can have a field-of-view greater than that of the object beam. One or more aspheric reflective surfaces can be used to couple an object beam into a holographic recording material at relatively steep angles.
1. An apparatus comprising:
a light source configured to produce a coherent beam;
a beam splitter configured to split the coherent beam into an object beam and a reference beam;
an object beam optical system configured to direct the object beam to interfere with the reference beam at a holographic recording material, wherein the object beam optical system comprises
a first lens configured to focus the object beam to a location within the holographic recording material; and
a second lens having a first surface and a second surface, wherein
the first surface has a non-planar shape configured such that substantially each ray of the object beam intersects the first surface with substantially normal incidence,
the second surface is different from the first surface, and
the second lens is configured to transmit the object beam into the holographic recording material such that substantially each ray of the object beam enters the holographic recording material substantially without refraction; and
a reference beam optical system configured to direct the reference beam to interfere with the object beam at the holographic recording material.
2. The apparatus of claim 1 wherein the first surface of the second lens is at least one of spherical, parabaloidal, or elliptical.
3. The apparatus of claim 2 wherein:
the second lens is hemispherical, and
the second lens is positioned such that a center of the second lens substantially coincides with a focus point of the object beam.
4. The apparatus of claim 2 wherein the second lens is a spherical section.
5. The apparatus of claim 1 wherein the second surface of the second lens is substantially planar, and wherein the second surface is coupled directly to the holographic recording material.
6. The apparatus of claim 1 wherein the second surface of the second lens is substantially planar, and wherein the second surface is coupled to the holographic recording material through at least one of: an index-matching fluid, a substrate attached to the holographic recording material, or a transparent portion of a platen supporting the second lens.
7. The apparatus of claim 1 comprising:
a platen configured to support the second lens, wherein the platen includes at least one of an index-matching fluid supply aperture or an index-matching fluid uptake aperture.
8. The apparatus of claim 1 wherein at least one portion of one surface of the second lens is a spherical section.
9. The apparatus of claim 1 wherein the first lens is a Fourier transform lens.
10. The apparatus of claim 1 wherein the object beam optical system includes a spatial light modulator configured to intensity modulate the object beam, the apparatus comprising:
a computer coupled to the spatial light modulator and programmed to control delivery of a rendered image to the spatial light modulator.
11. The apparatus of claim 1 wherein the light source comprises a laser.
12. The apparatus of claim 1 comprising:
a material holder configured to hold the holographic recording material; and
a material holder translation system operable to position the material holder holding the holographic recording material.
13. The apparatus of claim 1 wherein the object beam optical system comprises:
an object beam optics translation system configured to translate the first lens and the second lens with respect to the holographic recording material.
14. The apparatus of claim 1 wherein the first surface of the second lens is cylindrical.
15. The apparatus of claim 1 comprising:
a spatial light modulator configured to modulate the object beam to form at least one hogel in the holographic recording material, wherein the at least one hogel corresponds to data provided to the spatial light modulator.
16. The apparatus of claim 15 comprising:
a computer coupled to the spatial light modulator and configured to transmit the data to the spatial light modulator, wherein the data comprises data for at least one hogel of a rendered image.
17. The apparatus of claim 1 wherein the second lens is positioned such that a center of the second lens substantially coincides with a focus point of the object beam.
18. The apparatus of claim 1 wherein the second lens has an index of refraction substantially equal to an index of refraction of the holographic recording material.
19. An apparatus comprising:
a light source configured to produce a coherent beam;
a beam splitter configured to split the coherent beam into an object beam and a reference beam;
an object beam optical system configured to direct the object beam to interfere with the reference beam at a holographic recording material, wherein the object beam optical system comprises
a first lens configured to focus the object beam to a location within the holographic recording material; and
a second lens having a first surface and a second surface, wherein
the first surface has a shape configured such that, over substantially the entire first surface, the first surface receives the object beam with substantially normal incidence,
the second surface is different from the first surface,
the second surface is coupled to the holographic recording material, and
the second lens is configured to transmit, over substantially the entire second surface, the object beam into the holographic recording material substantially without refraction of the object beam as the object beam crosses the second surface; and
a reference beam optical system configured to direct the reference beam to interfere with the object beam at the holographic recording material.
20. The apparatus of claim 19 wherein the second surface of the second lens is substantially planar, and wherein the second surface is coupled directly to the holographic recording material.
21. The apparatus of claim 19 wherein the second surface of the second lens is substantially planar, and wherein the second surface is coupled to the holographic recording material through at least one of: an index-matching fluid, a substrate attached to the holographic recording material, or a transparent portion of a platen supporting the second lens.
22. The apparatus of claim 19 comprising:
a platen configured to support the second lens, wherein the platen includes at least one of an index-matching fluid supply aperture or an index-matching fluid uptake aperture.
23. The apparatus of claim 19 wherein the second lens is hemispherical.
24. The apparatus of claim 19 wherein the second lens is one of a spherical section or cylindrical.
25. The apparatus of claim 19 wherein the first lens is a Fourier transform lens.
26. The apparatus of claim 19 wherein the object beam optical system includes a spatial light modulator configured to intensity modulate the object beam, the apparatus comprising:
a computer coupled to the spatial light modulator and programmed to control delivery of a rendered image to the spatial light modulator.
27. The apparatus of claim 19 wherein the light source is at least one of a pulsed laser or a continuous wave laser.
28. The apparatus of claim 19 comprising:
a material holder configured to hold the holographic recording material; and
a material holder translation system operable to position the material holder holding the holographic recording material.
29. The apparatus of claim 19 wherein the object beam optical system comprises:
an object beam optics translation system configured to translate the first lens and the second lens with respect to the holographic recording material.
30. The apparatus of claim 19 comprising:
a spatial light modulator configured to modulate the object beam to form at least one hogel in the holographic recording material, wherein the at least one hogel corresponds to data provided to the spatial light modulator.
31. The apparatus of claim 30 comprising:
a computer coupled to the spatial light modulator and configured to transmit the data to the spatial light modulator, wherein the data comprises data for at least one hogel of a rendered image.
32. The apparatus of claim 19 wherein the second lens is positioned such that a center of the second lens substantially coincides with a focus point of the object beam.