Expanding field-of-view of near-to-eye display by hybrid angular and wavelength multiplexing.

Field-of-view (FOV) and resolution are two critical performance metrics of a near-to-eye display (NED) and are primarily limited by the refractive index (RI) of the waveguide combiner and the number of available pixel counts of the micro display. A high RI material (n = 2.0) is required to transfer an image exceeding a 60 degree full FOV using traditional techniques. We decouple FOV from resolution by wavelength-multiplexing multiple high-resolution FOVs followed by de-multiplexing those FOVs by volume holographic gratings. This approach increases the entire effective FOV beyond the RI-limited FOV while maintaining resolution. Using our new approach we experimentally demonstrate the transfer of images across a 60 degree full FOV through a waveguide with a RI-limited FOV of 30 degrees, which is a common limit for n = 1.5 material. Additional polarization multiplexing enables transferring a 90 degree FOV image over the n = 1.5 waveguide combiner.