Tunable focal waveguide-based see-through display with negative liquid crystal lens

Area of Science:

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

Background:

• Traditional see-through displays often suffer from fixed focal planes, leading to visual discomfort and limited augmented reality (AR) experiences.
• Achieving a comfortable AR experience requires addressing vergence-accommodation conflict, often caused by displays with a single focal plane.

Purpose of the Study:

• To present a novel see-through display system utilizing a planar holographic waveguide with a dynamically tunable focal plane.
• To enhance user comfort in augmented reality applications by enabling a wider range of focal distances.

Main Methods:

• Integration of a negative liquid crystal lens at the outcoupling point of a holographic waveguide.
• Manipulation of image distance through the tunable focal length of the liquid crystal lens, ranging from negative infinity to -65 cm.
• Control of polarization states to manage the see-through capability for the real scene and the input image.

Main Results:

• Demonstration of a prototype system with a 10.5° field-of-view (FOV) for non-infinite images.
• The liquid crystal lens successfully manipulates image distance, providing a tunable focal plane.
• The system maintains see-through functionality for the real scene while displaying augmented information.

Conclusions:

• The presented tunable focal plane see-through display offers a more comfortable AR experience compared to single focal plane systems.
• The polarization-dependent nature of the liquid crystal lens is key to simultaneously enabling see-through and image display functions.
• This technology represents a significant advancement in creating more immersive and user-friendly augmented reality systems.