Eyepiece for head-mounted display and method for making the same
A method, includes providing a wafer including a first surface grating extending over a first area of a surface of the wafer and a second surface grating extending over a second area of the surface of the wafer; de-functionalizing a portion of the surface grating in at least one of the first surface grating area and the second surface grating area; and singulating an eyepiece from the wafer, the eyepiece including a portion of the first surface grating area and a portion of the second surface grating area. The first surface grating in the eyepiece corresponds to an input coupling grating for a head-mounted display and the second surface grating corresponds to a pupil expander grating for the head-mounted display.
1. An article, comprising:
a planar waveguide comprising a first surface, the first surface comprising:
a first plurality of surface gratings;
a second plurality of surface gratings; and
a smooth portion between the first plurality of surface gratings and the second plurality of surface gratings,
the smooth portion comprising a first planar region at a first surface height and a second planar region at a second surface height above the first surface height, the first plurality of surface gratings and the second plurality of surface gratings extending above the first surface height, and the second planar region being adjacent either the first plurality of surface gratings or second plurality of surface gratings,
the second planar region extending over a de-functionalized portion of each of the first plurality of surface gratings or each of the second plurality of surface gratings and the second planar region is at the same height or higher than the first plurality of surface gratings or second plurality of surface gratings, wherein the surface grating of the de-functionalized portion remains but ceases to function as a grating.
2. The article of claim 1 , further comprising a reflective layer supported by each surface grating of the first plurality of surface gratings.
3. The article of claim 2 , wherein the reflective layer is a metal.
4. The article of claim 2 , wherein the first plurality of surface gratings and the reflective layer supported by each surface grating of the first plurality of surface gratings are configured to couple incident light into the planar waveguide.
5. The article of claim 1 , wherein the second plurality of surface gratings is configured to direct light guided by the planar waveguide out of the planar waveguide.
6. The article of claim 1 , wherein the second planar region extends 100 nm or less above the adjacent plurality of surface gratings.
7. The article of claim 1 , wherein the planar waveguide is a polymer waveguide.
8. The article of claim 1 , wherein the second planar region extends laterally over the de-functionalized portion by a distance which is greater than a pitch of the adjacent plurality of surface gratings.
9. The article of claim 1 , wherein the second planar region has a minimum lateral dimension of more than 30 mm for each surface grating of the plurality of second surface gratings.
10. The article of claim 1 , wherein each of the plurality of second surface gratings has a maximum lateral dimension of 30 mm or less.
11. The article of claim 10 , wherein at least one of the second plurality of surface gratings has a maximum lateral dimension that is different than the maximum lateral dimension of the other surface gratings of the second plurality of surface gratings.
12. The article of claim 1 , wherein each surface grating of the first plurality of surface gratings has a maximum lateral dimension of 5 mm or less.
13. The article of claim 12 , wherein at least one of the first plurality of surface gratings has a maximum lateral dimension that is different than the maximum lateral dimension the other surface gratings of the first plurality of surface gratings.
14. The article of claim 1 , wherein the de-functionalized portion extends over each surface grating of the first plurality of surface gratings or each surface grating of the second plurality of surface gratings by a distance which is greater than a pitch of the plurality of first surface gratings or a pitch of the plurality of second surface gratings.
15. The article of claim 14 , wherein the de-functionalized portion ceases to function as a grating.
16. The article of claim 1 , wherein the second planar region is a UV-curable resin or a thermally-curable resin.
17. The article of claim 1 , wherein the second planar region is the same material as the planar waveguide.