Method of manufacturing optical element and optical element
Provided are a method of manufacturing an optical element in which an optically-anisotropic layer having a small amount of in-plane unevenness can be prepared, and an optical element. The method of manufacturing an optical element is a method of manufacturing an optical element, the optical element including an optically-anisotropic layer that is formed using a liquid crystal composition including a liquid crystal compound, an alignment film that aligns the liquid crystal compound, and a support, the method including: an alignment film forming step of forming the alignment film on one surface of the support; and an optically-anisotropic layer forming step of forming the optically-anisotropic layer on the alignment film, in which the alignment film includes a photo-alignable material, the alignment film forming step includes an exposure step of exposing different in-plane positions of the alignment film to light components having different polarization directions, and the support includes a reflection suppressing portion that suppresses reflection of light in a wavelength range of at least a part of a light absorption band where a photochemical reaction occurs in the alignment film by irradiating a surface opposite to a surface where the alignment film is formed with the polarized light in the exposure step.
1. A method of manufacturing an optical element, the optical element including an optically-anisotropic layer that is formed using a liquid crystal composition including a liquid crystal compound, an alignment film that aligns the liquid crystal compound, and a support, the method comprising:
an alignment film forming step of forming the alignment film on one surface of the support; and
an optically-anisotropic layer forming step of forming the optically-anisotropic layer on the alignment film,
wherein the alignment film includes a photo-alignable material,
the alignment film forming step includes an exposure step of exposing different in-plane positions of the alignment film to light components having different polarization directions, and
the support includes a reflection suppressing portion that suppresses reflection of light in a wavelength range of at least a part of a light absorption band where a photochemical reaction occurs in the alignment film by irradiating a surface opposite to a surface where the alignment film is formed with the polarized light in the exposure step.
2. The method of manufacturing an optical element according to claim 1 ,
wherein in the exposure step, the alignment film is exposed to two or more polarized beams that are caused to interfere with each other.
3. The method of manufacturing an optical element according to claim 2 ,
wherein the two or more polarized beams are laser light.
4. The method of manufacturing an optical element according to claim 2 ,
wherein at least two beams among the two or more polarized beams have the same wavelength.
5. The method of manufacturing an optical element according to claim 2 ,
wherein at least two beams among the two or more polarized beams have the same light intensity.
6. The method of manufacturing an optical element according to claim 2 ,
wherein at least two beams among the two or more polarized beams are different polarized light components.
7. The method of manufacturing an optical element according to claim 2 ,
wherein the two or more polarized beams include polarized light components perpendicular to each other.
8. The method of manufacturing an optical element according to claim 2 ,
wherein the two or more polarized beams include left circularly polarized light and right circularly polarized light.
9. The method of manufacturing an optical element according to claim 2 ,
wherein in the exposure step, a polarization state of coherent light obtained by causing the two or more polarized beams to interfere with each other has a period pattern.
10. The method of manufacturing an optical element according to claim 9 ,
wherein the alignment film exhibits anisotropy through a photochemical reaction based on the period pattern of the polarization state of the coherent light obtained by causing the two or more polarized beams to interfere with each other.
11. The method of manufacturing an optical element according to claim 10 ,
wherein the optically-anisotropic layer has a liquid crystal alignment pattern based on the anisotropic period pattern of the alignment film.
12. The method of manufacturing an optical element according to claim 1 ,
wherein in the exposure step, light is caused to be incident into a polarization diffractive optical element such that the light is converted into polarized light, and the alignment film is exposed to the polarized light.
13. The method of manufacturing an optical element according to claim 12 ,
wherein the polarization diffractive optical element has a phase difference of λe/2 with respect to a wavelength λe of the light to which the polarization diffractive optical element exposes the alignment film.
14. The method of manufacturing an optical element according to claim 12 ,
wherein the light incident into the polarization diffractive optical element is linearly polarized light.
15. The method of manufacturing an optical element according to claim 1 ,
wherein in the exposure step, the different in-plane positions of the alignment film are exposed by freely changing a polarization direction of a focused polarized beam.
16. The method of manufacturing an optical element according to claim 15 ,
wherein the focused polarized beam is linearly polarized light.
17. The method of manufacturing an optical element according to claim 1 ,
wherein the light to which the alignment film is exposed is laser light.
18. The method of manufacturing an optical element according to claim 1 ,
wherein the alignment film exposed in the exposure step aligns the liquid crystal compound such that the liquid crystal compound has an alignment pattern in which a direction of an optical axis derived from the liquid crystal compound corresponds to a polarization direction of the light to which the alignment film is exposed.
19. The method of manufacturing an optical element according to claim 1 ,
wherein the alignment film exposed in the exposure step aligns the liquid crystal compound such that the liquid crystal compound has an alignment pattern in which a direction of an optical axis derived from the liquid crystal compound continuously changes while rotating in at least one in-plane direction.
20. The method of manufacturing an optical element according to claim 1 ,
wherein a wavelength of at least a part of a light absorption band of the alignment film is 200 nm to 500 nm.
21. The method of manufacturing an optical element according to claim 1 , comprising:
a peeling step of peeling the support after the optically-anisotropic layer forming step.
22. The method of manufacturing an optical element according to claim 1 ,
wherein the support includes a reflection suppressing portion that is provided on a surface opposite to a surface where the alignment film is formed and suppresses reflection of light in a wavelength range of at least a part of a light absorption band where a photochemical reaction occurs in the alignment film, and
the method comprises a peeling step of peeling the support and the reflection suppressing portion together after the optically-anisotropic layer forming step.