Volume hologram waveguide with coupled photopolymers
Techniques for optical waveguides with multiple layers in a stack arrangement are described herein. In an example, an optical waveguide system includes a waveguide substrate, a first holographic optical element, a second holographic optical element, and an optical de-coupling layer. The first holographic optical element includes a first photopolymer layer and excluding a first polymer substrate and the second holographic optical element includes a second photopolymer layer. The first photopolymer layer is attached to the waveguide substrate and to either the second holographic optical element or the optical de-coupling layer.
1 . An apparatus comprising:
a light source configured to emit light;
a housing;
an optical waveguide system encapsulated in the housing and configured to receive the light, the optical waveguide system comprising:
a waveguide substrate having a first surface and a second surface opposite the first surface;
a first optical de-coupling layer coupled to the first surface of the waveguide substrate and characterized by a first refractive index of less than or equal to 1.25;
an anti-scratch layer disposed on the first optical de-coupling layer;
a first holographic optical element comprising a first photopolymer layer and excluding a first polymer substrate; and
a second a holographic optical element comprising a second photopolymer layer; and
a second optical de-coupling layer characterized by a second refractive index of less than or equal to 1.25,
wherein the first photopolymer layer is in direct contact with the second surface of the waveguide substrate, and
wherein the second photopolymer layer is in direct contact with and disposed between the first photopolymer layer and the first optical de-coupling layer.
2 . The apparatus of claim 1 , wherein the waveguide substrate is a first waveguide substrate, and wherein the optical waveguide system further comprises:
a second waveguide substrate, wherein the first holographic optical element and the second holographic optical element are disposed between the first waveguide substrate and the second waveguide substrate.
3 . The apparatus of claim 2 , wherein the optical waveguide system further comprises:
a third optical de-coupling layer characterized by a third refractive index of less than or equal to 1.25; and
a third holographic optical element comprising a third polymer substrate, wherein:
the third holographic optical element is in direct contact with and disposed between the second waveguide substrate and the third optical de-coupling layer, and
the third optical de-coupling layer is in direct contact and disposed between the second holographic optical element and the third holographic optical element.
4 . The apparatus of claim 2 , wherein the first waveguide substrate is a plastic waveguide substrate, and wherein the second waveguide substrate is a glass waveguide substrate.
5 . An optical waveguide system comprising:
a waveguide substrate;
a first holographic optical element comprising a first photopolymer layer and excluding a first polymer substrate;
a second holographic optical element comprising a second photopolymer layer; and
an optical de-coupling layer coupled to the waveguide substrate and characterized by a first refractive index of less than or equal to 1.25,
wherein the first photopolymer layer is in direct contact with and disposed between the waveguide substrate and the second holographic optical element, and
wherein the second photopolymer layer is disposed between the first photopolymer layer and the optical de-coupling layer.
6 . The optical waveguide system of claim 5 , further comprising:
a third holographic optical element comprising a third photopolymer layer, wherein the second photopolymer layer is in direct contact with and disposed between the first photopolymer layer and the third photopolymer layer.
7 . The optical waveguide system of claim 6 , wherein the waveguide substrate is a first waveguide substrate, and wherein the optical waveguide system further comprises:
a second waveguide substrate; and
a liquid optically clear adhesive (LOCA) layer disposed on the second waveguide substrate, wherein the third photopolymer layer is in direct contact with and disposed between the second photopolymer layer and the LOCA layer.
8 . The optical waveguide system of claim 5 , wherein the second photopolymer layer is in direct contact with the first photopolymer layer and optical de-coupling layer.
9 . The optical waveguide system of claim 8 , wherein the waveguide substrate is a first waveguide substrate, and wherein the optical waveguide system further comprises:
a second waveguide substrate; and
a third photopolymer layer that is in direct contact with and disposed between the second photopolymer layer and the optical de-coupling layer.
10 . The optical waveguide system of claim 5 , wherein the waveguide substrate is a first waveguide substrate, and wherein the optical waveguide system further comprises:
a second waveguide substrate,
wherein the first holographic optical element and the second holographic optical element are disposed between the first waveguide substrate and the second waveguide substrate, and wherein at least one of the first waveguide substrate or the second waveguide substrate is a plastic waveguide substrate.
11 . The optical waveguide system of claim 5 , further comprising:
an anti-scratch layer disposed on the optical de-coupling layer.
12 . The optical waveguide system of claim 5 , wherein the first photopolymer layer is configured to receive and optically couple first light and second light to the waveguide substrate, wherein the first light is characterized by a first wavelength within a first wavelength range, and wherein the second light is characterized by a second wavelength within a non-overlapping second wavelength range.
13 . A system comprising:
a light source configured to emit light; and
an optical waveguide system configured to receive the light, the optical waveguide system comprising:
a waveguide substrate;
a first holographic optical element comprising a first photopolymer layer and excluding a first polymer substrate;
a second holographic optical element comprising a second photopolymer layer; and
an optical de-coupling layer coupled to the waveguide substrate and characterized by a first refractive index of less than or equal to 1.25,
wherein the first photopolymer layer is in direct contact with and disposed between the waveguide substrate and the second holographic optical element, and
wherein the second photopolymer layer is disposed between the first photopolymer layer and the optical de-coupling layer.
14 . The system of claim 13 , wherein the optical waveguide system further comprises:
a third holographic optical element that includes a third photopolymer layer and that excludes a third polymer substrate, wherein the second photopolymer layer is disposed between the first photopolymer layer and the third photopolymer layer.
15 . The system of claim 14 , wherein the waveguide substrate is a first waveguide substrate, and wherein the optical waveguide system further comprises:
a second waveguide substrate, wherein the third photopolymer layer is disposed between the second photopolymer layer and the second waveguide substrate.
16 . The system of claim 13 , wherein the optical waveguide system further comprises:
a third holographic optical element, wherein the second holographic optical element is disposed between the first holographic optical element and the third holographic optical element, and wherein each one of the first holographic optical element, the second holographic optical element, and the third holographic optical element is configured to operate in a different wavelength range.
17 . The system of claim 16 , wherein the waveguide substrate is a first waveguide substrate, and wherein the optical waveguide system further comprises:
a second waveguide substrate,
wherein the first holographic optical element, the second holographic optical element, and the third holographic optical element are disposed between the first waveguide substrate and the second waveguide substrate.
18 . The system of claim 13 , wherein the optical waveguide system further comprises:
a third holographic optical element; and
an additional optical de-coupling layer that is disposed between the second holographic optical element and the third holographic optical element.
19 . The system of claim 18 , wherein the waveguide substrate is a first waveguide substrate, wherein the optical waveguide system further comprises:
a second waveguide substrate,
wherein the third holographic optical element is in direct contact with and disposed between the additional optical de-coupling layer and the second waveguide substrate.
20 . The system of claim 19 , wherein the third holographic optical element comprises a third photopolymer layer and excludes a third polymer substrate, and wherein the third photopolymer layer is in direct contact with and disposed between the additional optical de-coupling layer and the second waveguide substrate.