A device includes a waveguide. The device also includes a plurality of grating sets coupled with the waveguide and configured to, during a plurality of time periods, couple a plurality of input image lights into the waveguide and couple the input image lights out of the waveguide as a plurality of output image lights. The plurality of input image lights have a substantially same input field of view (“FOV”) with a substantially same symmetry axis. A combined output FOV of the output image lights is larger than the input FOV.