Polarization-dependent metasurfaces for 2D/3D switchable displays
Intellectual Property Status: Patent(s) Pending
The Capasso group at Harvard propose to use metasurfaces with tailored polarization dependent responses to realize a 2D/3D switchable display. This innovation enables lightweight, high resolution 2D/3D switchable displays which can be used in 1) smartphone display panels, 2) augmented reality glasses, 3) head mounted virtual reality displays.
Compared with the previous designs based on liquid crystal lenses (LC lenses), this approach has several advantages:
- Metasurfaces offer precise control over the phase profile simultaneously at two polarizations, reducing aberrations and crosstalk. This improves the overall image quality.
- Metasurfaces can be adapted to arbitrary sizes, as small as 5 mm or as large as hundreds of micrometers. This enables potential high resolution 3D displays.
- Metasurfaces can be designed for an arbitrary pair of orthogonal polarizations, in particular, circular polarizations. Therefore, they are compatible with back-reflection removal components, and other polarization control components.
- Metasurfaces are ultrathin, and lightweight.
The concept is readily applicable, although the actual implementation requires further engineering of both the metasurfaces and the underlying light emitting elements. Currently, the group has demonstrated metasurface-based 2D/3D switchable displays with a between-view angular separation of 10° , using titanium dioxide nanopillars in air. The major challenge that need to be addressed in the future is the directionality of the light emitting elements.