Architectures and methods for outputting different wavelength light out of waveguides
View Patent ↗Architectures are provided for selectively outputting light for forming images, the light having different wavelengths and being outputted with low levels of crosstalk. In some embodiments, light is incoupled into a waveguide and deflected to propagate in different directions, depending on wavelength. The incoupled light then outcoupled by outcoupling optical elements that outcouple light based on the direction of propagation of the light. In some other embodiments, color filters are between a waveguide and outcoupling elements. The color filters limit the wavelengths of light that interact with and are outcoupled by the outcoupling elements. In yet other embodiments, a different waveguide is provided for each range of wavelengths to be outputted. Incoupling optical elements selectively incouple light of the appropriate range of wavelengths into a corresponding waveguide, from which the light is outcoupled.
1. An optical device comprising:
a first incoupling optical element configured to receive an incoming beam of light;
a first waveguide having a first major surface and a second major surface, wherein the first incoupling optical element is configured to incouple into the first waveguide light, from the incoming beam of light, having a first wavelength, such that the incoupled light having the first wavelength propagates through the first waveguide by multiple total internal reflections between the first and the second major surfaces;
a first optical filter on one of the first major surface or the second major surface, the first optical filter configured to absorb incoupled light having a wavelength different from the first wavelength;
a second waveguide having a first major surface and a second major surface;
a second incoupling optical element configured to incouple light, from the incoming beam of light, having a second wavelength different from the first wavelength into the second waveguide, such that the incoupled light having the second wavelength propagates through the second waveguide by multiple total internal reflections between the first and the second major surfaces of the second waveguide; and
a second optical filter configured to absorb light, from the incoming beam of light, having the first wavelength and transmit light having the second wavelength.
2. The optical device of claim 1 , wherein the first incoupling optical element is on one of the first major surface of the first waveguide or the second major surface of the first waveguide.
3. The optical device of claim 1 , wherein at least a portion of the first optical filter is laterally displaced from the first incoupling optical element along an axis parallel to one of the first major surface or the second major surface.
4. The optical device of claim 1 , wherein the first incoupling optical element is configured to transmit light, from the incoming beam of light, having a wavelength different from the first wavelength.
5. The optical device of claim 1 , wherein the second incoupling optical element is on one of the first major surface of the second waveguide or the second major surface of the second waveguide.
6. The optical device of claim 5 , wherein the second optical filter is between the first waveguide and the second waveguide.
7. The optical device of claim 5 , further comprising:
a third waveguide having a first major surface and a second major surface;
a third incoupling optical element configured to incouple light, from the incoming beam of light, having a third wavelength into the third waveguide, such that the incoupled light having the third wavelength propagates through the third waveguide by multiple total internal reflections between the first and the second major surfaces of the third waveguide; and
a third optical filter configured to absorb light, from the incoming beam of light, having the first wavelength and the second wavelength and transmit light having the third wavelength.
8. The optical device of claim 7 , wherein the third incoupling optical element is on one of the first major surface of the third waveguide or the second major surface of the third waveguide.
9. The optical device of claim 8 , wherein, as seen in a top-down view, the third incoupling optical element is laterally displaced from the first incoupling optical element and the second incoupling optical element.
10. The optical device of claim 8 , wherein the third optical filter is between the second waveguide and the third waveguide.
11. The optical device of claim 1 , wherein, as seen in a top-down view, the first incoupling optical element is laterally displaced from the second incoupling optical element.
12. The optical device of claim 1 , further comprising a first outcoupling optical element configured to outcouple the incoupled light having the first wavelength.
13. The optical device of claim 12 , wherein the first optical filter is in a path of propagation of light from the first incoupling optical element to the first outcoupling optical element.
14. The optical device of claim 13 , further comprising:
a first light distributing element configured to receive incoupled light having the first wavelength and distribute the incoupled light having the first wavelength to the first outcoupling optical element.
15. The optical device of claim 14 , wherein the first light distributing element is disposed over a portion of the first optical filter.
16. The optical device of claim 12 , wherein the first outcoupling optical element comprises one or more diffractive optical elements.
17. The optical device of claim 16 , wherein the one or more diffractive optical elements of the first outcoupling optical element comprises one or more of an analog surface relief grating (ASR), a binary surface relief structure (BSR), a hologram, and a switchable diffractive optical element.
18. The optical system of claim 17 , wherein the switchable diffractive optical element comprises a switchable Polymer Dispersed Liquid Crystal (PDLC) grating.
19. The optical device of claim 1 , wherein the first outcoupling optical element is disposed over a portion of the first optical filter.
20. An optical device comprising:
a first incoupling optical element configured to receive an incoming beam of light;
a first waveguide having a first major surface and a second major surface, wherein the first incoupling optical element is configured to incouple into the first waveguide light, from the incoming beam of light, having a first wavelength, such that the incoupled light having the first wavelength propagates through the first waveguide by multiple total internal reflections between the first and the second major surfaces;
a first optical filter on one of the first major surface or the second major surface, the first optical filter configured to absorb incoupled light having a wavelength different from the first wavelength; and
a first outcoupling optical element configured to outcouple the incoupled light having the first wavelength,
wherein the first outcoupling optical element comprises one or more diffractive optical elements, and
wherein the one or more diffractive optical elements of the first outcoupling optical element comprises one or more of an analog surface relief grating (ASR), a binary surface relief structure (BSR), a hologram, and a switchable diffractive optical element.
21. The optical system of claim 20 , wherein the switchable diffractive optical element comprises a switchable Polymer Dispersed Liquid Crystal (PDLC) grating.