Transparent illumination panel and method of manufacturing
A light diffuser panel for coupling to an optical element, includes a plurality of first type layers of a first type of material with a refractive index n 1 , and a plurality of second type layers of a second type of material with a different refractive index n 2 , wherein each of the first type layers and each of the second type layers are arranged to form a plurality of interface surfaces between alternating first type layers and second type layers, tilted at a plurality of angles with tilt axes that are parallel to a plane of the light diffuser panel, such that visible light from the optical element is transmitted through the light diffuser panel and the interface surfaces, and a portion of the visible light from the optical element is reflected out of the light diffuser panel at each of the interface surfaces.
1. A light diffuser panel for coupling to an optical element, comprising:
a plurality of first type layers comprising a first type of material with a refractive index n 1 ; and
a plurality of second type layers comprising a second type of material with a refractive index n 2 different from the refractive index n 1 ; and
a polarization rotator plate;
wherein each of the plurality of the first type layers and each of the plurality of the second type layers are arranged, such that each of the plurality of the first type layers is between two second type layers, to form a plurality of interface surfaces between alternating ones of the first type layers and the second type layers,
the plurality of the interface surfaces are tilted at a plurality of angles respectively with a plurality of tilt axes that are parallel to a plane of the light diffuser panel,
wherein visible light from the optical element is transmitted through the light diffuser panel and each of the plurality of the interface surfaces, and portions of the visible light from the optical element are reflected out of the light diffuser panel at each of the plurality of the interface surfaces and
wherein the polarization rotator plate is configured to rotate light polarization of the visible light that has transmitted through at least one of the plurality of the interface surfaces.
2. The light diffuser panel according to claim 1 , wherein θ is one of the plurality of angles at one of the interface surfaces,
a relative reflectance of S-polarized light at the one of the interface surfaces is R s ,
a relative reflectance of P-polarized light at the one of the interface surfaces is R p , and
R s and R p are respectively
R
s
=
[
n
1
*
cos
θ
-
n
2
*
1
-
(
n
1
n
2
sin
θ
)
2
n
1
*
cos
θ
+
n
2
*
1
-
(
n
1
n
2
sin
θ
)
2
]
2
R
p
=
[
n
1
*
1
-
(
n
1
n
2
sin
θ
)
2
-
n
2
*
cos
θ
n
1
*
1
-
(
n
1
n
2
sin
θ
)
2
+
n
2
*
cos
θ
]
2
.
3. The light diffuser panel according to claim 1 , wherein each of the plurality of the first type layers and each of the plurality of the second type layers have a thickness that is greater than a largest wavelength of the visible light.
4. The light diffuser panel according to claim 1 , wherein each of the plurality of the angles is 45°.
5. The light diffuser panel according to claim 1 , wherein a total reflectance of each of the plurality of the interface surfaces is less than 2%.
6. The light diffuser panel according to claim 1 , wherein the first type layers comprise a polycarbonate material, and the second type layers comprise an acrylic material.
7. The light diffuser panel according to claim 1 , wherein at least one edge portion of the light diffuser panel comprises one of the plurality of the second type layers and is configured to receive the visible light from the optical element.
8. The light diffuser panel according to claim 1 , wherein the optical element comprises at least one of a light emitting diode (LED), a laser diode, a fluorescent light source, an optical waveguide, an optical reflector, an optical refractor, and a polarizer.
9. The light diffuser panel according to claim 1 , wherein the portions of the visible light from the optical element are reflected out of one side of the light diffuser panel.
10. A light diffuser panel for coupling to an optical element,
comprising:
a plurality of first type layers comprising a first type of material with a refractive index n 1 ; and
a plurality of second type layers comprising a second type of material with a refractive index n 2 different from the refractive index n 1 ;
wherein each of the plurality of the first type layers and each of the plurality of the second type layers are arranged, such that each of the plurality of the first type layers is between two second type layers, to form a plurality of interface surfaces between alternating ones of the first type layers and the second type layers,
the plurality of the interface surfaces are tilted at a plurality of angles respectively with a plurality of tilt axes that are parallel to a plane of the light diffuser panel,
wherein visible light from the optical element is transmitted through the light diffuser panel and each of the plurality of the interface surfaces, and portions of the visible light from the optical element are reflected out of the light diffuser panel at each of the plurality of the interface surfaces;
wherein the plurality of the first type layers are arranged at a plurality of predetermined positions with a plurality of predetermined interval distances between central planes of adjacent first type layers,
each of the plurality of the predetermined interval distances is T times an adjacent predetermined interval distance that is closer to the optical element,
each of the plurality of the predetermined interval distances is 1/T times an adjacent predetermined interval distance that is further from the optical element, where
T is a relative transmittance of each of the plurality of the interface surfaces,
T is equal to 1−R, and
R is a relative reflectance of each of the plurality of the interface surfaces.
11. The light diffuser panel according to claim 10 , wherein each of the plurality of the first type layers and each of the plurality of the second type layers have a thickness that is greater than a largest wavelength of the visible light.