Compact display with extended pixel resolution

1 . An apparatus comprising:

a dichroic wedge;

a spatial light modulator optically coupled to the dichroic wedge; and

a display optically coupled to the spatial light modulator, the display comprising:

a waveguide having a first surface and a second surface that is different from the first surface, the first surface disposed to receive modulated light from the spatial light modulator;

a first diffractive optical element on the first surface of the waveguide, the first diffractive optical element having a first diffraction characteristic and configured to receive first modulated light from the spatial light modulator;

a second diffractive optical element on the first surface of the waveguide, the second diffractive optical element having a second diffraction characteristic different than the first diffraction characteristic and configured to receive second modulated light from the spatial modulator; and

a third diffractive optical element on the second surface of the waveguide.

2 . The apparatus of claim 1 , wherein the first diffractive optical element comprises a surface relief diffractive optical element.

3 . The apparatus of claim 1 , wherein the first diffractive optical element comprises a volume hologram.

4 . The apparatus of claim 1 , wherein the display further comprises a fourth diffractive optical element on the first surface of the waveguide.

5 . The apparatus of claim 1 , wherein the second diffractive optical element is adjacent the first diffractive optical element.

6 . The apparatus of claim 1 , wherein the dichroic wedge comprises a first dichroic mirror and a second dichroic mirror, the second dichroic mirror at an angle with respect to the first dichroic mirror.

7 . The apparatus of claim 1 , further comprising a prism optically coupled between the dichroic wedge and the spatial light modulator.

8 . The apparatus of claim 1 , further comprising a fly's eye array optically coupled between the dichroic wedge and the spatial light modulator.

9 . The apparatus of claim 1 , further comprising an actuated plate optically coupled between the spatial light modulator and the display.

10 . The apparatus of claim 1 , wherein the first diffractive optical element has an optical power.

11 . The apparatus of claim 1 , further comprising:

a first light source optically coupled to the dichroic wedge, the first light source configured to produce first light having a first color; and

a second light source optically coupled to the dichroic wedge, the second light source laterally spaced from the first light source, the second light source configured to produce second light having the first color.

12 . The apparatus of claim 11 , further comprising:

a third light source optically coupled to the dichroic wedge, the third light source configured to produce third light having a second color different than the first color; and

a fourth light source optically coupled to the dichroic wedge, the fourth light source configured to produce fourth light having the second color, the fourth light source laterally spaced from the second light source.

13 . The apparatus of claim 1 , wherein the spatial light modulator is configured to:

receive first light at a first angle;

modulate the first light to produce modulated first light;

receive second light at a second angle; and

modulate the second light to produce second modulated light.

14 . The apparatus of claim 13 , wherein the first diffractive optical element is configured to receive the first modulated light and to shift the first modulated light to produce a first image, and the second diffractive optical element is configured to receive the second modulated light and to shift the second modulated light to produce a second image, wherein the second image is shifted with respect to the first image.

15 . The apparatus of claim 14 , wherein the second image is shifted with respect to the first image half a pixel in a vertical direction and half a pixel in a horizontal direction.

16 . An apparatus comprising:

a dichroic wedge;

a spatial light modulator optically coupled to the dichroic wedge; and

a display optically coupled to the spatial light modulator, the display comprising:

a waveguide;

a first diffractive optical element on the waveguide, the first diffractive optical element having a first diffraction characteristic and configured to receive first modulated light from the spatial light modulator;

a second diffractive optical element on the waveguide, the second diffractive optical element adjacent the first diffractive optical element, the second diffractive optical element having a second diffraction characteristic different than the first diffraction characteristic and configured to receive second modulated light from the spatial light modulator, the second diffractive optical element disposed on a same surface of the waveguide as the first diffractive optical element; and

a third diffractive optical element on a different surface of the waveguide than the surface on which the first and second diffractive optical elements are disposed.

17 . The apparatus of claim 16 , wherein the first diffractive optical element has a first diffraction angle, the second diffractive optical element has a second diffraction angle, and the second diffraction angle is different than the first diffractive angle.

18 . The apparatus of claim 16 , wherein the spatial light modulator is configured to:

receive first light at a first angle;

modulate the first light to produce the first modulated light;

receive second light at a second angle; and

modulate the second light to produce the second modulated light.

19 . An apparatus comprising:

a dichroic wedge;

a spatial light modulator optically coupled to the dichroic wedge, the spatial light modulator configured to:

receive first light at a first angle;

modulate the first light to produce first modulated light;

receive second light at a second angle, the second angle different than the first angle; and

modulate the second light to produce second modulated light; and

a display optically coupled to the spatial light modulator, the display comprising:

a waveguide having a first surface and a second surface that is different from the first surface;

a first diffractive optical element on the first surface of the waveguide, the first diffractive optical element configured to receive the first modulated light;

a second diffractive optical element on the first surface of the waveguide, the second diffractive optical element configured to receive the second modulated light; and

a third diffractive optical element on the second surface of the waveguide;

wherein the waveguide is configured to combine the first modulated light and the second modulated light.

20 . The apparatus of claim 19 , wherein the first diffractive optical element has a first diffraction angle, the second diffractive optical element has a second diffraction angle, and the second diffraction angle is different than the first diffractive angle.