Optical system with waveguide redirecting reflector
A display system may include a waveguide, an input coupler, a cross-coupler, and an output coupler for displaying images to a user. A reflector may be disposed on the waveguide. The input coupler may couple light into the waveguide and towards the reflector. The reflector may reflect the light towards the cross-coupler. The cross-coupler may expand and redirect the light. The output coupler may direct the light towards an eye box. The reflector may allow the input coupler to be mounted at a peripheral portion of the waveguide that overlaps a display projector without portions of the field of view of the image light being cut off but the geometry of the waveguide and without causing the display system to be unnecessarily bulky or uncomfortable to wear.
1 . A display comprising:
a waveguide, wherein the waveguide comprises:
a first substrate having a first lateral surface and a second lateral surface opposite the first lateral surface; and
a second substrate mounted to the first lateral surface of the first substrate, wherein the second substrate overlaps some but not all of the first lateral surface of the first substrate;
a first optical coupler configured to couple light into the waveguide;
a second optical coupler on the waveguide, wherein the second optical coupler is disposed on the first substrate;
a third optical coupler on the waveguide; and
a reflector on the waveguide, wherein the reflector is disposed on the second substrate and the reflector has a lateral surface tilted at a non-orthogonal angle with respect to the first lateral surface, and wherein
the reflector is configured to redirect, towards the second optical coupler, the light coupled into the waveguide by the first optical coupler,
the second optical coupler is configured to redirect, towards the third optical coupler, the light reflected by the reflector, and
the third optical coupler is configured to couple the light out of the waveguide.
2 . The display of claim 1 , wherein the second optical coupler is configured to expand a pupil of the light.
3 . A display comprising:
a waveguide, wherein the waveguide comprises:
a first substrate having a first lateral surface and a second lateral surface opposite the first lateral surface; and
a second substrate mounted to the first lateral surface of the first substrate, wherein the second substrate overlaps some but not all of the first lateral surface of the first substrate;
a first optical coupler configured to couple light into the waveguide;
a second optical coupler on the waveguide, wherein the second optical coupler is disposed on the first substrate;
a third optical coupler on the waveguide; and
a reflector on the waveguide, wherein the reflector is disposed on the second substrate and comprises a set of parallel partially reflective layers, and wherein
the reflector is configured to redirect, towards the second optical coupler, the light coupled into the waveguide by the first optical coupler,
the second optical coupler is configured to redirect, towards the third optical coupler, the light reflected by the reflector, and
the third optical coupler is configured to couple the light out of the waveguide.
4 . A display comprising:
a waveguide, wherein the waveguide comprises:
a first substrate having a first lateral surface and a second lateral surface opposite the first lateral surface; and
a second substrate mounted to the first lateral surface of the first substrate, wherein the second substrate overlaps some but not all of the first lateral surface of the first substrate;
a first optical coupler configured to couple light into the waveguide;
a second optical coupler on the waveguide, wherein the second optical coupler is disposed on the first substrate;
a third optical coupler on the waveguide; and
a reflector on the waveguide, wherein the reflector is disposed on the second substrate and comprises an edge facet of the second substrate, and wherein
the reflector is configured to redirect, towards the second optical coupler, the light coupled into the waveguide by the first optical coupler,
the second optical coupler is configured to redirect, towards the third optical coupler, the light reflected by the reflector, and
the third optical coupler is configured to couple the light out of the waveguide.
5 . A display comprising:
a waveguide, wherein the waveguide comprises a substrate having a first lateral surface and a second lateral surface opposite the first lateral surface;
an input coupler configured to couple light into the waveguide and comprising:
a reflective input coupling prism mounted to the first lateral surface of the substrate, and
a dispersion compensation wedge mounted to the second lateral surface and at least partially overlapping the input coupling prism;
a reflector on the substrate and configured to reflect the light coupled into the waveguide by the input coupler;
a cross-coupler configured to redirect the light reflected by the reflector; and
an output coupler configured to couple, out of the waveguide, the light redirected by the cross-coupler.
6 . The display of claim 5 , wherein the cross-coupler comprises a surface relief grating, a volume hologram, or a mirror.
7 . The display of claim 5 , wherein the output coupler comprises a surface relief grating, a volume hologram, or a mirror.
8 . A display comprising:
a substrate having a first lateral surface, a second lateral surface, and an edge facet extending from the first lateral surface to the second lateral surface;
a first optical coupler configured to couple light into the substrate and towards the edge facet, wherein the first optical coupler comprises a prism with a surface facing the first lateral surface and a reflective surface, and wherein the reflective surface is configured to reflect the light into the substrate through the surface facing the first lateral surface;
a second optical coupler on the substrate, the edge facet being configured to reflect the light towards the second optical coupler and the second optical coupler being configured to redirect the light; and
a third optical coupler configured to receive the light from the second optical coupler and configured to redirect the light.
9 . The display of claim 8 , further comprising:
an additional substrate layered onto the second lateral surface of the substrate, the third optical coupler being disposed on the additional substrate and being configured to couple the light out of the additional substrate, wherein the second optical coupler comprises a louvered mirror, and the third optical coupler comprises volume holograms.
10 . The display of claim 8 , wherein the first optical coupler further comprises a wedge configured to compensate for dispersion of the light, mounted to the second lateral surface, and at least partially overlapping the prism.
11 . The display of claim 10 , wherein the wedge at least partially overlaps the prism.