Display system having a plurality of light pipes for a plurality of light emitters

1. A method for forming an optical device, the method comprising:

forming a light pipe with one or more sidewalls, at least one of which includes a roughened sidewall surface, wherein the light pipe comprises a first end having a light input surface and a second end having a light output surface, wherein the light input surface is opposite the light output surface to define a length along the one or more sidewalls between the light input surface and the light output surface, wherein the roughened sidewall surface extends from the first end to the second end and is nonparallel to each of the light input surface and the light output surface, wherein the length between the light input surface and the light output surface is greater than a width orthogonal to the length between the one or more sidewalls; and

coupling the light pipe with the roughened sidewall surface to a light emitter; and

coupling an assembly comprising the light pipe with the roughened sidewall surface and the light emitter to a spatial light modulator,

wherein the light input surface is configured to receive light from the light emitter and wherein the light output surface is configured to output light through the light output surface to the spatial light modulator.

2. The method of claim 1 , wherein forming the light pipe with the roughened sidewall surface comprises subjecting a sidewall of the light pipe to an abrasive treatment.

3. The method of claim 2 , wherein the abrasive treatment is a mechanical polishing process.

4. The method of claim 1 , wherein forming the light pipe with the roughened sidewall surface comprises forming the light pipe in a mold comprising a roughened interior surface.

5. The method of claim 1 , wherein coupling the light pipe to the light emitter comprises coupling the light input surface of the light pipe to a plurality of light emitters.

6. The method of claim 5 , wherein the light pipe is one of a plurality of light pipes forming the assembly, further comprising an other light pipe coupled to only a single light emitter.

7. The method of claim 6 , wherein the single light emitter and the plurality of light emitters emit light of different colors.

8. The method of claim 6 , wherein the light pipe and other light pipe have different heights, and wherein the light pipe and the other light pipe each define a respective sub pupil at the different heights configured to provide light at different depth planes.

9. The method of claim 1 , further comprising coupling the assembly comprising the light pipe and the light emitter to a polarizing beam splitter, wherein the spatial light modulator and the assembly are disposed facing different surfaces of the polarizing beam splitter.

10. The method of claim 1 , wherein the light pipe is one of a plurality of light pipes forming the assembly and wherein the light emitter is one of plurality of light emitters such that each light pipe is oriented to localize outputted light on a different location on the spatial light modulator than other light pipes and different component color images are formed at the different locations.

11. The method of claim 10 , wherein each of the plurality of light pipes is oriented to output light on an associated location on the spatial light modulator, wherein the associated locations for each of the light pipes is separated from the associated locations for others of the light pipes.

12. The method of claim 10 , wherein the light output surface of each of the light pipes has a larger area than the light input surface of the respective light pipe such that one or more of the light pipes is an elongated structure with multi-faceted, tapered roughened sidewall surfaces from the respective light output surface to the respective light input surface, and wherein a ratio of the length to the width is approximately 4:3.

13. The method of claim 1 , wherein the light pipe comprises a light redirecting feature at a light input end of the light pipe, and wherein the light redirecting feature comprises one or more of a diffuser, a grating, and a prism.

14. The method of claim 1 , wherein the assembly, the light pipe, and the spatial light modulator form a projection system, further comprising:

coupling a waveguide to the projection system, the waveguide comprising a light incoupling optical element configured to receive light from the spatial light modulator.

15. The method of claim 14 , wherein the waveguide is one of a plurality of waveguides forming a waveguide stack, each of the waveguides comprising a light incoupling optical element, wherein coupling the waveguide to the projection system comprises coupling the plurality of waveguides to the projection system, and wherein the light incoupling optical element of one or more first waveguides is spatially offset from the light incoupling optical element of two or more other waveguides, as seen in a plan view viewed in a direction of propagation of the light into the waveguide stack.

16. The method of claim 15 , wherein the light incoupling optical elements of at least two of the two or more other waveguides at least partially overlap, as seen in the plan view.

17. The method of claim 15 , wherein each waveguide of the stack of waveguides comprises a light outcoupling optical element configured to output incoupled light with different amounts of divergence than one or more other waveguides of the stack of waveguides.

18. The method of claim 10 , wherein the spatial light modulator is a single spatial light modulator that is coupled to each of the light pipes of the assembly.

19. The method of claim 1 , wherein the method further comprises positioning the assembly and the spatial light modulator relative to a beam splitter such that the light from light emitter is passed through the light pipe, reflected by the beam splitter to the spatial light modulator to reflect and modulate the light, which is then propagated through the beam splitter to an eyepiece of a wearable AR display.

20. The method of claim 1 , wherein the light pipe has a cross-sectional shape that is at least one of rectangular, square, hexagonal, or circular, and wherein the cross-sectional shape changes at least once along the length.