Hybrid polymer waveguide and methods for making the same
In some embodiments, a head-mounted augmented reality display system comprises one or more hybrid waveguides configured to display images by directing modulated light containing image information into the eyes of a viewer. Each hybrid waveguide is formed of two or more layers of different materials. The thicker of the layers is a highly optically transparent “core” layer, and the thinner layer comprises a pattern of protrusions and indentations to form, e.g., a diffractive optical element. The pattern may be formed by imprinting. The hybrid waveguide may include additional layers, e.g., forming a plurality of alternating core layers and thinner patterned layers. Multiple waveguides may be stacked to form an integrated eyepiece, with each waveguide configured to receive and output light of a different component color.
1. An augmented reality display system comprising:
a waveguide comprising:
an optically transmissive core layer having a major surface opposite an other major surface; and
an optically transmissive auxiliary layer on the major surface, the auxiliary layer comprising:
incoupling diffractive optical elements configured to direct, into the waveguide, at least a portion of light that is incident on the incoupling diffractive optical elements such that the directed light propagates in the waveguide; and
outcoupling diffractive optical elements configured to extract, out of the waveguide, incoupled light that is propagating in the waveguide,
wherein the auxiliary layer is thinner than the core layer and is formed of a material different from material forming the core layer,
wherein the material forming the core layer has a refractive index greater than 1.65, and
wherein at least one of the incoupling diffractive optical elements or the outcoupling diffractive optical elements include nanophotonic structures comprising lines of material and intervening indentations that are arranged between the lines of material and that extend completely through the auxiliary layer and partially into the core layer.
2. The augmented reality display system of claim 1 , wherein the core layer and the auxiliary layer are each formed of a polymer or a resin.
3. The augmented reality display system of claim 1 , wherein material forming the auxiliary layer has a refractive index differing by about 0.05 or more from the refractive index of material forming the core layer.
4. The augmented reality display system of claim 1 , wherein the core layer has a thickness of 100-5000 μm, and the auxiliary layer has a thickness of between 0.01-5 μm.
5. The augmented reality display system of claim 1 , further comprising an additional auxiliary layer thinner than the core layer and immediately adjacent the other major surface.
6. The augmented reality display system of claim 5 , wherein the additional auxiliary layer comprises additional outcoupling diffractive optical elements configured to extract incoupled modulated light out of the waveguide.
7. The augmented reality display system of claim 1 , further comprising an additional core layer disposed on an opposite side of the auxiliary layer from the core layer.
8. The augmented reality display system of claim 1 , further comprising a plurality of core layers alternating with auxiliary layers thinner than the core layers, the auxiliary layers formed of material different from the core layers.
9. The augmented reality display system of claim 8 , wherein the core layers are formed of a same material.
10. The augmented reality display system of claim 9 , wherein the auxiliary layers are formed of a same material.
11. The augmented reality display system of claim 8 , wherein one or more of the auxiliary layers comprise optical gratings different from one or more other auxiliary layers.
12. The augmented reality display system of claim 1 , further comprising a spatial light modulator configured to output modulated light comprising image information, wherein the spatial light modulator is arranged to output the modulated light to be incident on the incoupling diffractive optical elements to be directed into the waveguide.
13. The augmented reality display system of claim 1 , wherein the one or more nanophotonic structures include other intervening indentations that extend partially into the auxiliary layer and that do not extend into the core layer.
14. The augmented reality display system of claim 1 , wherein the material forming the core layer has a refractive index greater than 1.7.
15. The augmented reality display system of claim 1 , wherein the material forming the core layer has a refractive index greater than 1.8.
16. The augmented reality display system of claim 1 , wherein the incoupling diffractive optical elements include a first set of nanophotonic structures comprising the lines of material and the intervening indentations that are arranged between the lines of material and that extend completely through the auxiliary layer and partially into the core layer, and wherein the outcoupling diffractive optical elements include a second set of nanophotonic structures comprising lines of material and intervening indentations that are arranged between the lines of material and that extend partially into the auxiliary layer and that do not extend into the core layer.
17. The augmented reality display system of claim 1 , wherein the outcoupling diffractive optical elements include a first set of nanophotonic structures comprising the lines of material and the intervening indentations that are arranged between the lines of material and that extend completely through the auxiliary layer and partially into the core layer, and wherein the incoupling diffractive optical elements include a second set of nanophotonic structures comprising lines of material and intervening indentations that are arranged between the lines of material and that extend partially into the auxiliary layer and that do not extend into the core layer.
18. The augmented reality display system of claim 1 , wherein the waveguide further comprises an additional optically transmissive auxiliary layer on the other major surface, the additional auxiliary layer comprising one or more additional diffractive optical elements that include one or more of:
additional incoupling diffractive optical elements configured to direct, into the waveguide, at least a portion of light that is incident on the additional incoupling diffractive optical elements such that the directed light propagates in the waveguide; or
additional outcoupling diffractive optical elements configured to extract, out of the waveguide, incoupled light that is propagating in the waveguide.
19. The augmented reality display system of claim 1 , wherein the waveguide further comprises an additional core layer on an opposite side of the auxiliary layer from the core layer.