METHOD AND SYSTEM FOR PUPIL SEPARATION IN A DIFFRACTIVE EYEPIECE WAVEGUIDE DISPLAY
A pupil separation system includes a first optical element disposed at a first position along an axis and including a first input surface, a first beamsplitter optically coupled to the first input surface, and a first output surface optically coupled to the first beamsplitter. The pupil separation system also includes a second optical element disposed at a second position along the axis and including a second input surface, a second beamsplitter optically coupled to the second input surface, and a second output surface optically coupled to the second beamsplitter. The pupil separation system further includes a third optical element disposed at a third position along the axis and including a third input surface, a reflective surface optically coupled to the third input surface, and a third output surface optically coupled to the reflective surface.
1 . A pupil separation system comprising:
a first optical element disposed at a first position along an axis, wherein the first optical element comprises:
a first input surface;
a first beamsplitter optically coupled to the first input surface; and
a first output surface optically coupled to the first beamsplitter;
a second optical element disposed at a second position along the axis, wherein the second optical element comprises:
a second input surface;
a second beamsplitter optically coupled to the second input surface; and
a second output surface optically coupled to the second beamsplitter;
a third optical element disposed at a third position along the axis, wherein the third optical element comprises:
a third input surface;
a reflective surface optically coupled to the third input surface; and
a third output surface optically coupled to the reflective surface.
2 . The pupil separation system of claim 1 wherein the first position, the second position, and the third position are disposed in order along the axis.
3 . The pupil separation system of claim 1 wherein the first beamsplitter comprises a dichroic beamsplitter operable to transmit light in a red wavelength range and reflect light in a blue wavelength range and a green wavelength range.
4 . The pupil separation system of claim 3 wherein the dichroic beamsplitter comprises a green dichroic mirror and a blue dichroic mirror.
5 . The pupil separation system of claim 3 wherein the dichroic beamsplitter comprises a high-pass filter.
6 . The pupil separation system of claim 1 wherein the second beamsplitter comprises a dichroic beamsplitter operable to transmit light in a green wavelength range and reflect light in a blue wavelength range.
7 . The pupil separation system of claim 6 wherein the dichroic beamsplitter comprises a blue dichroic mirror.
8 . The pupil separation system of claim 1 wherein the third optical element comprises a right angle prism operable to reflect light in a green wavelength range.
9 . The pupil separation system of claim 8 wherein the reflective surface comprises a metallized coating.
10 . The pupil separation system of claim 1 further comprising a red color filter operable to transmit a red wavelength range disposed adjacent the first output surface.
11 . The pupil separation system of claim 1 further comprising a blue color filter operable to transmit a blue wavelength range disposed adjacent the second output surface.
12 . The pupil separation system of claim 1 further comprising a green color filter operable to transmit a green wavelength range disposed adjacent the third output surface.
13 . The pupil separation system of claim 1 wherein the first output surface, the second output surface, and the third output surface are coplanar.
14 . The pupil separation system of claim 1 wherein the first input surface is perpendicular to the second input surface and the third input surface.
15 . The pupil separation system of claim 1 wherein the first beamsplitter is parallel to the second beamsplitter.
16 . The pupil separation system of claim 15 wherein the reflective surface is parallel to the second beamsplitter.
17 . The pupil separation system of claim 1 wherein:
the first beamsplitter is oriented at 45° to the first input surface;
the second beamsplitter is oriented at −45° to the second input surface; and
the reflective surface is oriented at −45° to the third input surface.
18 . The pupil separation system of claim 1 wherein the pupil separation system is characterized by an index of refraction greater than or equal to 2.0.
19 . The pupil separation system of claim 1 further comprising:
a scanning mirror operable to rotate around an axis; and
an eyepiece waveguide including:
a first waveguide layer including a first incoupling grating (ICG) operable to receive light transmitted through the first output surface;
a second waveguide layer including a second ICG operable to receive light transmitted through the second output surface, wherein the second ICG is spatially offset from the first ICG; and
a third waveguide layer including a third ICG operable to receive light transmitted through the third output surface, wherein the third ICG is spatially offset from the first ICG and the second ICG.
20 . The pupil separation system of claim 19 wherein:
the first ICG is located at a first distance from the first output surface;
the second ICG is located at a second distance from the second output surface, wherein the second distance is less than the first distance; and
the third ICG is located at a third distance from the third output surface, wherein the third distance is less than the second distance.