US 12,147,038 B2
Optical systems with interleaved light redirectors
Se Baek Oh, Millbrae, CA (US); Bradley C. Steele, San Diego, CA (US); Byron R. Cocilovo, San Jose, CA (US); Francesco Aieta, San Francisco, CA (US); and Graham B. Myhre, San Jose, CA (US)
Assigned to Apple Inc., Cupertino, CA (US)
Filed by Apple Inc., Cupertino, CA (US)
Filed on Aug. 13, 2019, as Appl. No. 16/539,818.
Claims priority of provisional application 62/735,560, filed on Sep. 24, 2018.
Prior Publication US 2020/0096771 A1, Mar. 26, 2020
Int. Cl. G02B 27/01 (2006.01); G02B 5/08 (2006.01); G02B 5/18 (2006.01); G02B 5/32 (2006.01); G02B 27/09 (2006.01)
CPC G02B 27/0172 (2013.01) [G02B 5/08 (2013.01); G02B 5/1814 (2013.01); G02B 5/32 (2013.01); G02B 27/0944 (2013.01); G02B 2027/0178 (2013.01); G02B 2027/0187 (2013.01)] 17 Claims
OG exemplary drawing
 
1. An electronic device comprising:
a projector; and
an optical system configured to receive light from the projector and configured to redirect the light in a first direction, wherein the optical system includes an input coupler, an output coupler, and a waveguide that propagates the light along a second direction, the output coupler comprising:
a grating medium having a first surface and a second surface opposite the first surface,
a first light-redirecting element configured to redirect the light in a third direction and in the first direction, the first light-redirecting element extending from the first surface to the second surface of the grating medium and comprising a first set of diffractive gratings having a first set of grating vectors extending from a first k-space region to a second k-space region and having second set of grating vectors extending parallel to the first set of grating vectors and from a third k-space region to a fourth k-space region, and
a second light-redirecting element that overlaps the first light-redirecting element and that is configured to redirect the light in a fourth direction opposite the third direction and in the first direction, wherein the waveguide has a first exterior surface and a second exterior surface opposite the first exterior surface, the first and second light-redirecting elements are superimposed in a same volume of the grating medium that is located within an interior of the waveguide between the first exterior surface and the second exterior surface, the output coupler is configured to couple the light out of the waveguide through the first surface of the grating medium, the second light-redirecting element extends from the first surface to the second surface of the grating medium, and the second set of light-redirecting elements comprises a second set of diffractive gratings having a third set of grating vectors extending from the first k-space region to the third k-space region and having a fourth set of grating vectors extending parallel to the third set of grating vectors and from the second k-space region to the fourth k-space region.