Optical laminate
An optical laminate includes a wavelength selective reflective element which is provided with a reflection layer selectively reflecting light in a specific reflection wavelength region, and an absolute phase adjustment layer which is provided on at least one surface side of the wavelength selective reflective element and has optical isotropy, and the absolute phase adjustment layer has an in-plane distribution of at least one of a refractive index or a film thickness, and thus has an in-plane distribution of an optical path length in a film thickness direction.
1. An optical laminate comprising:
a wavelength selective reflective element which is provided with a reflection layer selectively reflecting light in a specific reflection wavelength region; and
an absolute phase adjustment layer which is provided on at least one surface side of the wavelength selective reflective element and has optical isotropy,
wherein the absolute phase adjustment layer has a uniform film thickness, and has an in-plane distribution of a refractive index, and thus has an in-plane distribution of an optical path length in a film thickness direction, and
wherein the optical laminate reflects light in the specific reflection wavelength region by the wavelength selective reflective element, of light incident from the absolute phase adjustment layer side, as reflected light having a wavefront different from a wavefront of the incident light.
2. The optical laminate according to claim 1 ,
wherein the reflection layer of the wavelength selective reflective element is formed of a cholesteric liquid crystal layer.
3. The optical laminate according to claim 1 ,
wherein the reflection layer of the wavelength selective reflective element is formed of a dielectric multilayer film in which at least two layers having different refractive indices are alternately laminated in multiple layers.
4. The optical laminate according to claim 1 ,
wherein the in-plane distribution of the optical path length has a pattern in which the optical path length is changed stepwise.
5. The optical laminate according to claim 1 ,
wherein the in-plane distribution of the optical path length has a pattern in which the optical path length is gradually increased with an increase in distance from one point.
6. The optical laminate according to claim 1 ,
wherein the in-plane distribution of the optical path length has a pattern in which the optical path length is gradually reduced with an increase in distance from one point.
7. The optical laminate according to claim 4 , wherein the pattern is periodically repeated.
8. The optical laminate according to claim 5 , wherein the pattern is periodically repeated.
9. The optical laminate according to claim 6 , wherein the pattern is periodically repeated.
10. An optical laminate comprising:
a wavelength selective reflective element which is provided with a reflection layer selectively reflecting light in a specific reflection wavelength region; and
an absolute phase adjustment layer which is provided on at least one surface side of the wavelength selective reflective element and has optical isotropy,
wherein the wavelength selective reflective element is flat,
wherein the absolute phase adjustment layer has an in-plane distribution of at least one of a refractive index or a film thickness, and thus has an in-plane distribution of an optical path length in a film thickness direction, and
wherein the optical laminate reflects light in the specific reflection wavelength region by the wavelength selective reflective element, of light incident from the absolute phase adjustment layer side, as reflected light having a wavefront different from a wavefront of the incident light.