High refractive index optical device formed based on solid crystal and fabrication method thereof

1. An optical element, comprising:

an alignment structure configured to provide a predetermined in-plane alignment pattern; and

a solid crystal grown on the alignment structure based on a solid crystal material through crystallization, wherein the alignment structure is configured to interact with solid crystal molecules to at least partially align the solid crystal molecules in the predetermined in-plane alignment pattern as the solid crystal grows on the alignment structure,

wherein the solid crystal has a principal refractive index of at least 2.2 and a birefringence of at least 0.3.

2. The optical element of claim 1 , wherein the solid crystal is in a form of a continuous layer.

3. The optical element of claim 1 , wherein

the solid crystal includes a plurality of solid crystals disposed in a stacked configuration, and

the optical element further includes a plurality of alignment structures disposed between the solid crystals.

4. The optical element of claim 1 , wherein the principal refractive index is between 2.2 and 2.6 and the birefringence is at least about 0.4, the principal refractive index being a refractive index in a direction parallel to an axis of the solid crystal, and the axis of the solid crystal being an axis along which the solid crystal has a highest refractive index.

5. The optical element of claim 1 , wherein the alignment structure is configured to at least partially define uniform in-plane orientations, periodic or non-periodic in-plane orientations in a linear direction, in a radial direction, or in a circumferential direction for an axis of the solid crystal.

6. The optical element of claim 1 , wherein an orientation of an axis of the solid crystal is spatially constant or spatially varying within the solid crystal, the axis of the solid crystal being an axis along which the solid crystal has a highest refractive index.

7. The optical element of claim 1 , wherein the optical element is configured to function as a Panchratnam Berry Phase optical element.

8. The optical element of claim 1 , wherein the alignment structure includes at least one of:

a photo-alignment material layer;

a mechanically rubbed alignment layer;

an alignment layer with anisotropic nanoimprint;

an anisotropic relief directly formed on a substrate;

a ferroelectric or ferromagnetic material deposited on the substrate;

a thin crystalline layer or crystalline substrate; or

an alignment layer formed by crystallization in a presence of a magnetic field or an electric field.

9. The optical element of claim 1 , wherein

the solid crystal molecules include a first plurality of solid crystal molecules disposed in contact with the alignment structure and a second plurality of solid crystal molecules disposed over the first plurality of solid crystal molecules,

orientations of axes of the first plurality of solid crystal molecules are defined by the alignment structure, and

orientations of axes of the second plurality of solid crystal molecules twist in a helical fashion.

10. The optical element of claim 1 , wherein

the solid crystal includes chiral organic solid crystal molecules or organic solid crystal molecules doped with chiral dopants.

11. The optical element of claim 1 , wherein

the solid crystal includes a plurality of grains with grain boundaries, and at least one grain is at least partially aligned by the alignment structure on which the solid crystal is disposed, and

the solid crystal includes a plasticizer configured to release local crystalline strain to provide a smooth transition between neighboring grains.

12. The optical element of claim 1 , wherein the solid crystal is switchable between an amorphous state and an aligned crystal state through at least one of a thermal based switching, a polarization based switching, or a photo sensitivity based switching.

13. The optical element of claim 1 , wherein the solid crystal is uniaxially or biaxially anisotropic.

14. The optical element of claim 1 , wherein the solid crystal comprises at least one of:

a saturated or unsaturated polycyclic hydrocarbon, including at least one of anthracene, tetracene, pentacene, a derivative of the anthracene, a derivative of the tetracene, or a derivative of the pentacene;

nitrogen, sulfur, and oxygen heterocycle;

quinoline, benzothiophene, or benzopyran;

bent and asymmetric acene including at least one of phenanthrene, phenanthroline, pyrene, fluoranthene, a derivative of the phenanthrene, a derivative of the phenanthroline, a derivative of the pyrene, or a derivative of the fluoranthene;

2,6-naphthalene dicarboxylic acid, 2,6 dimethyl carboxylic ester crystal molecules, a derivative of the 2,6-naphthalene dicarboxylic acid, or a derivative of the 2,6 dimethyl carboxylic ester crystal molecules; or

biphenyl, terphenyl, quaterphenyl, or phenylacetylene, or derivatives of the biphenyl, terphenyl, quaterphenyl, or phenylacetylene including substitutes with alkyl groups, cyano groups, isothiocyanate groups, fluorine, chlorine or fluorinated ether.

15. The optical element of claim 1 , wherein the solid crystal is a single crystal layer or a polycrystal layer.

16. The optical element of claim 1 , wherein the solid crystal is an organic solid crystal layer comprising at least one polycyclic aromatic hydrocarbon or a derivative of the polycyclic aromatic hydrocarbon.

17. The optical element of claim 1 , wherein the solid crystal is an organic crystal layer comprising molecules containing a ring structure system and two terminal group systems.

18. The optical element of claim 1 , wherein the solid crystal is an organic crystal layer comprising crystalline polymers having precursors including aromatic hydrocarbon, heteroarene groups, or derivatives thereof.

19. The optical element of claim 1 , wherein the solid crystal is an organic crystal layer comprising a binder formed by at least one of amorphous polymers with aliphatic, hetroaliphatic, aromatic hydrocarbon, or heteroarene groups.