Methods for Three-Dimensional Arrangement of Anisotropic Molecules, Patterned Anisotropic Films, and Optical Elements Therewith

• US 20190317450A1
• Filed: 02/11/2019
• Published: 10/17/2019
• Est. Priority Date: 04/17/2018
• Status: Active Grant

• Current Assignee: META Platforms Technologies LLC (Meta Platforms, Inc. (f/k/a Facebook, Inc.))
• Original Assignee: Facebook Technologies, LLC (Meta Platforms, Inc. (f/k/a Facebook, Inc.))
• Inventors: Yaroshchuk, Oleg, Lam, Wai Sze Tiffany, McEldowney, Scott Charles, LU, Lu
• Granted Patent: US 11,561,507 B2
• Time in Patent Office: Days
• CPC Class Codes: G03H 1/02 Details of features involved during the holographic process; Replication of holograms without interference recording
• CPC Class Codes: G03H 1/0248 Volume holograms
• CPC Class Codes: G03H 1/04 Processes or apparatus for producing holograms G03H1/26 takes precedence
• CPC Class Codes: G03H 1/041 Optical element in the object space affecting the object beam, not otherwise provided for
• CPC Class Codes: G03H 1/18 Particular processing of hologram record carriers, e.g. for obtaining blazed holograms photographic processing in general G03C, G03D
• CPC Class Codes: G03H 2001/026 Recording materials or recording processes G03H2226/11 takes precedence; corresponding details, see subgroups of G03H2260/00
• CPC Class Codes: G03H 2001/0413 for recording transmission holograms
• CPC Class Codes: G03H 2001/0415 for recording reflection holograms
• CPC Class Codes: G03H 2001/0484 Arranged to produce three-dimensional fringe pattern
• CPC Class Codes: G03H 2210/10 Modulation characteristics, e.g. amplitude, phase, polarisation
• CPC Class Codes: G03H 2222/31 Polarised light
• CPC Class Codes: G03H 2222/34 Multiple light sources
• CPC Class Codes: G03H 2223/24 Reflector; Mirror
• CPC Class Codes: G03H 2240/15 Polarisation modulation

Abstract

The invention relates to a method of creation of three-dimensional alignment patterns that includes providing a layer of optically recordable and polarization sensitive material having a thickness that is greater than, or equal to, a predefined thickness, and concurrently illuminating the optically recordable medium with two coherent beam of same or different polarization with predetermined angle between the beams such that the said beams impinge from the same side or from the opposite sides upon the layer of the recordable material. The invention further relates to polarization volume holograms based on the said alignment patterns and polarization holographic element including a single layer or a stack of several layers of optically recordable materials containing single or multiple polarization volume holograms.

Claims

1. A method of creating orientational patterns in a bulk of photosensitive materials, comprising:

providing a layer of optically recordable polarization sensitive and photocrosslinkable material having a thickness that is greater than, or equal to, a predefined thickness, a first surface and a second surface that is opposite to the first surface; and

concurrently illuminating the layer of optically recordable material with two coherent beams of polarized light thereby inducing periodic orientational patterns.

2. The method of claim 1, wherein the beams are circularly polarized.

3. The method of claim 2, wherein convergence angle of the beams is less than 90°

, and the beams have orthogonal circular polarizations thereby inducing cycloidal orientational patterns in the layer of optically recordable material.

4. The method of claim 3, wherein the beams impinge on the same surface of the layer of recordable material.

5. The method of claim 3, wherein the beams impinge on the opposite surfaces of the layer of recordable material.

6. The method of claim 2, wherein the convergence angle of the beams is 180±

45°

, and the beams have same circular polarizations thereby inducing helical orientational patterns in the layer of optically recordable material.

7. The method of claim 6, wherein the beams impinge on the opposite surfaces of the layer of recordable material.

8. The method of claim 6, wherein the beams impinge on the same surface of the layer of recordable material.

9. The method of claim 3, wherein incidence angles of the recording beams are equal.

10. The method of claim 3, wherein incidence angles of the recording beams are not equal.

11. The method of claim 1, wherein the beams are collimated.

12. The method of claim 1, wherein one beam has a plane wave front and the other beam has a spherical wave front.

13. The method of claim 1, wherein both beams have spherical wave fronts.

14. The method of claim 1, wherein the optically recordable polarization sensitive and photocrosslinkable material is a monomer or oligomer including a photosensitive fragment undergoing cycloaddition reaction.

15. The method of claim 1, wherein the optically recordable polarization sensitive and photocrosslinkable material is a polymer or copolymer including a photosensitive fragment undergoing cycloaddition reaction.

16. The method of claim 15, wherein the photosensitive fragment is a cinnamate fragment.

17. The method of claim 15, wherein the polymer is selected from the group consisting of a liquid crystal polymer and an amorphous polymer.

18. The method of claim 1, wherein the patterns are created at an ambient temperature or a temperature corresponding to liquid crystal phase.

19. The method of claim 1, further comprising annealing the layer of optically recordable material with the periodic orientational patterns, thereby enhancing the periodic orientational patterns.

20. The method of claim 1, wherein the periodic orientational patterns include variation of the orientation of the optically recordable material along each axis of the Cartesian coordinate system, one axis of the Cartesian coordinate system being perpendicular to the first surface.