Patent attributes
VHOEs with expanded acceptance angle ranges are described as well as various systems and methods for fabricating VHOEs with expanded acceptance angle ranges. The VHOE with expanded acceptance angle range may include two or more individual Bragg gratings. The two or more individual Bragg gratings have the same diffraction geometry but with shifted Bragg conditions. Having the same diffraction geometry means when light is incident on the VHOE including two or more individual Bragg gratings, the diffracted light from each of the Bragg gratings is co-linear or overlapping with the diffracted light from the other Bragg gratings. The Bragg condition for each of the Bragg gratings are shifted with respect to each neighboring Bragg grating by an amount up to the acceptance angle range of each individual Bragg grating.
