| abstract |
A near-eye optical display system that may be utilized in augmented reality applications and devices includes a diffractive waveguide having diffractive optical elements (DOEs) configured for in-coupling, exit pupil expansion, and out-coupling. An electrically-modulated tunable liquid crystal (LC) lens is located between the diffractive grating and the eyes of the user. A polarizing filter is located on the other side of the diffractive grating so that light from the real world enters the system with a particular polarization state, for example, TM-polarized. The tunable LC lens is configured to impart variable focus on light that has an opposite polarization state, for example TE-polarized. The optical display system is arranged to be polarization-sensitive so that virtual images from an imager are out-coupled from the diffractive waveguide with TE-polarization. The tunable LC lens may thus impart variable focus to the virtual images due to the lens' sensitivity to TE-polarization. |