Design and analysis of glasses-free three-dimensional display based on multi-level diffractive lenses

Area of Science:

• Optics and Photonics
• Display Technology
• 3D Imaging

Background:

• Glasses-free 3D display technology faces challenges due to theoretical limitations and a lack of systematic research in multi-level diffractive lenses (MDLs).
• Existing MDL designs often struggle with chromatic aberrations and limited focal length capabilities, hindering their practical application.

Purpose of the Study:

• To propose a novel design method for multi-level diffractive lenses (MDLs) enabling operation at multiple wavelengths and focal lengths.
• To address the limitations of current glasses-free 3D display technologies by enhancing MDL performance.

Main Methods:

• The direct binary search (DBS) algorithm was employed to optimize the microstructure height of MDL units for multi-wavelength and multi-focus performance.
• Scalar diffraction simulations were used to design and evaluate a three-wavelength, five-focus MDL.
• Off-axis focusing was achieved by cropping MDLs and integrating them into a view modulator for 3D display applications.

Main Results:

• A designed three-wavelength, five-focus MDL demonstrated the ability to correct chromatic aberrations while maintaining multi-focus functionality.
• Simulations confirmed that the view modulator achieved 87.6% brightness uniformity and below 10% crosstalk.
• Analysis revealed a trade-off between the field of view (FOV) and view modulator size in MDL-based designs.

Conclusions:

• The proposed MDL design method offers a viable solution for advanced glasses-free 3D displays.
• MDL-based displays exhibit significant advantages in brightness uniformity and low crosstalk.
• Further research is needed to overcome FOV limitations in current MDL-based 3D display systems.