Hybrid coupling diffractive optical element
A multi-functional diffractive optical element (DOE) for redirecting light into a waveguide and providing higher order aberration correction is described. The multi-functional DOE may be positioned on, connected to, adjacent to, or within a waveguide, and in some examples is positioned at, or near, the exit pupil of the projector lens. In an example, a head-mounted display (HMD) is configured to output artificial reality content, comprising a waveguide configured to receive input light and configured to output the received input light to an eyebox. The HMD further comprises a projector configured to input light into the waveguide, the projector comprising a display, a projection lens, and a multi-functional diffractive optical element (DOE) configured to redirect light from the projector into the waveguide and provide higher order aberration correction of the light from the display.
1. A head-mounted display (HMD) configured to output artificial reality content, comprising:
a waveguide configured to receive input light and configured to output the received input light to an eyebox;
a projector configured to input light into the waveguide, the projector comprising:
a display;
a projection lens; and
a multi-functional diffractive optical element (DOE) configured to redirect light from the projector into the waveguide,
wherein a length of the projector along its optical axis from a stop of the projection lens to the display is less than 4 mm,
wherein the stop is positioned opposite the projection lens from a focal plane of the projection lens, wherein the stop is positioned between the multi-functional DOE and the projection lens.
2. The HMD of claim 1 , wherein the multi-functional DOE includes a linear phase profile and a higher order aberration correcting phase profile.
3. The HMD of claim 2 , wherein the multi-functional DOE includes a rotationally symmetric higher order aberration correcting phase profile and a non-rotationally symmetric phase profile.
4. The HMD of claim 3 , wherein the multi-functional DOE is configured to compensate for the aberrations of the projection lens.
5. The HMD of claim 1 , wherein the multi-functional DOE is positioned to within 500 mm of a stop of the projection lens.
6. The HMD of claim 5 , wherein the multi-functional DOE is positioned adjacent to a major surface of the waveguide.
7. The HMD of claim 1 , wherein the multi-functional DOE is a transmissive DOE or a reflective DOE.
8. A projection lens comprising:
one or more lens elements having optical power and configured to collimate light emitted at or near a focal plane of the projection lens;
a multi-functional diffractive optical element (DOE) comprising:
a linear phase profile; and
a higher order aberration correcting phase profile, wherein the higher order aberration correcting phase profile is configured to provide higher order aberration correction of light incident on the multi-functional DOE; and
a lens stop positioned opposite the one or more lens elements from the focal plane and positioned between the multi-functional DOE and the one or more lens elements,
wherein a length of the projection lens along its optical axis from the lens stop of the projection lens to a display is less than 4 mm.
9. The projection lens of claim 8 , wherein the periodic phase profile is configured to redirect light incident on the multi-functional DOE into a waveguide.
10. The projection lens of claim 8 , wherein the higher order aberration correcting phase profile is configured to compensate for the aberrations of a projection lens that is configured to direct light to the multi-functional DOE.
11. The projection lens of claim 8 , wherein the higher order aberration correcting phase profile includes a rotationally symmetric higher order aberration correcting phase profile and a non-rotationally symmetric phase profile.
12. The projection lens of claim 8 , wherein the multi-functional DOE comprises a transmissive DOE.
13. The projection lens of claim 8 , wherein the multi-functional DOE comprises a reflective DOE.
14. The projection lens of claim 8 , wherein the multi-functional DOE comprises a metasurface or a metamaterial.
15. A method of projecting an image, the method comprising:
emitting light from an electronic display;
collimating the emitted light via a projection lens;
redirecting the collimated emitted light via a multi-functional DOE; and
compensating for the aberrations of the projection lens via the multi-functional DOE,
wherein a length of the projection lens along its optical axis from a stop of the projection lens to the electronic display is less than 4 mm,
wherein the stop is positioned opposite the projection lens from the electronic display, wherein the stop is positioned between the multi-functional DOE and the projection lens.
16. The method of claim 15 , wherein compensating for the aberrations of the projection lens includes inducing a rotationally symmetric phase delay profile and a non-rotationally symmetric phase delay profile to the wavefront of the collimated emitted light.
17. The method of claim 16 , wherein the redirecting the collimated emitted light comprises redirecting the collimated emitted light into a waveguide.
18. The method of claim 17 , further comprising:
positioning the multi-functional DOE at a major surface of the waveguide.
19. The method of claim 15 , further comprising:
positioning the multi-functional DOE within 500 mm from a stop of the projection lens.
20. The method of claim 15 , further comprising:
positioning the multi-functional DOE within 4 mm from the electronic display.
21. A projector lens comprising:
one or more lens elements having optical power and configured to collimate light emitted at or near a focal plane of the projector lens;
a multi-functional diffractive optical element (DOE) comprising:
a linear phase profile; and
a higher order aberration correcting phase profile configured to provide higher order aberration correction to light incident on the multi-functional DOE; and
a lens stop positioned opposite the one or more lens elements from the focal plane and positioned between the multi-functional DOE and the one or more lens elements.