Beam steering for virtual/augmented reality displays with a cycloidal diffractive waveplate

Area of Science:

• Optics and Photonics
• Display Technology
• Human-Computer Interaction

Background:

• Virtual reality (VR) and augmented reality (AR) systems require precise eye tracking for enhanced user experience.
• Existing eye-tracking technologies face challenges with efficiency, response time, and integration into compact display systems.

Purpose of the Study:

• To propose and demonstrate a novel switchable beam steering device for eye tracking in VR/AR systems.
• To achieve high diffraction efficiency and overcome color dispersion issues for full-color displays.

Main Methods:

• Development of a cycloidal diffractive waveplate (CDW) with high diffraction efficiency (>95%).
• Integration of a broadband polarization switch using a liquid crystal cell and achromatic quarter-wave film.
• Cascading multiple CDWs to achieve multiple diffraction angles and employing strategies to suppress color dispersion.

Main Results:

• The CDW achieved over 95% diffraction efficiency for circularly polarized light.
• A broadband polarization switch was successfully developed to convert linearly polarized light.
• Multiple diffraction angles were achieved by cascading CDWs, with proposed solutions for color dispersion in full-color displays.

Conclusions:

• The proposed switchable beam steering device offers high diffraction efficiency, fast response, low power consumption, and cost-effectiveness.
• This technology shows significant promise for advancing eye-tracking capabilities in emerging VR and AR display systems.