Patent ID: 11947314
Assignee: A9.COM, INC.
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 11:
12. An apparatus comprising:
a volume holographic optical element (VHOE) with expanded angular range, the VHOE comprising:
a. a first Bragg grating having a first diffraction geometry and a first Bragg condition; and
b. a second Bragg grating having a second diffraction geometry and a second Bragg condition;
wherein the first diffraction geometry is substantially identical to the second diffraction geometry, and wherein the second Bragg condition is shifted with respect to the first Bragg condition by an offset angle,
wherein the first Bragg grating is configured to diffract, at a first diffraction angle, a light beam that is incident to the VHOE at an incident angle,
wherein the second Bragg grating is configured to diffract, at a second diffraction angle, the light beam that is incident at the incident angle, and
wherein the second diffraction angle is substantially the same as the first diffraction angle; and

a waveguide combiner configured to combine first light from real imagery with second light from a light engine,
wherein the VHOE is coupled with the waveguide combiner.