Chinese Journal of Liquid Crystals and Displays, Volume. 39, Issue 5, 646(2024)

Polarized light multiplexing liquid crystal grating waveguide for AR near-eye display systems

Zijian LIN1, Lisheng YAO3, Huajian JIN1, Jianbin QIU1, Yun YE1,2, Sheng XU1,2, Qun YAN1,2, Tailiang GUO1,2, Wanlong ZHANG3、*, and Enguo CHEN1,2、**
Author Affiliations
  • 1National & Local United Engineering Laboratory of Flat Panel Display Technology,College of Physics and Information Engineering,Fuzhou University,Fuzhou 350108,China
  • 2Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China(Mindu Innovation Laboratory),Fuzhou 350108,China
  • 3Nanophotonics Research Centre,Institute of Microscale Optoelectronics,Shenzhen University,Shenzhen 518060,China
  • show less

    The thin optical waveguide combiner is responsible for pupil expansion of augmented reality (AR) displays. The exit pupil guides the display information into human eyes by inducing multiple diffractions from the coupling region with extension. However, this multiple diffraction may lead to the gradual weakening of exit pupil brightness along the spatial distribution of the light path, resulting in uneven brightness. In particular, when the coupling elements are fabricated by liquid crystal polarization volume grating (LCPVG), which is only sensitive to a kind of circularly polarized light according to the Bragg grating property, the orthogonal circularly polarized light will be directly transmitted, wasting the rest of display information. To address this issue, this paper proposes an optical waveguide AR display system based on LCPVG, which provides the left-handed and right-handed circular polarization light multiplexing, achieving large pupil area with good uniformity. The LCPVG is designed in the k-space to achieve the maximum field of view with the diffraction wavelength of 532 nm, combining the micro-display unit which consists of a micro-LED (μLED) display with a set of matching projection lenses, providing the exit pupil size of 45 mm×25 mm. The experimental results show that the diagonal field of view of the waveguide system reaches the expected 32.86° with the substrate refractive index of 1.51. Compared with the scheme that only responds to a single circular polarized light, the uniformity measured by the nine-point method is increased by 48.8%, the overall uniformity is increased by 34.1%, and the optical efficiency of the waveguide combiner is also improved by 1.2 times. This work provides valuable guidance and reference for the design of polarization volume grating waveguides for AR display systems.

    Keywords
    Tools

    Get Citation

    Copy Citation Text

    Zijian LIN, Lisheng YAO, Huajian JIN, Jianbin QIU, Yun YE, Sheng XU, Qun YAN, Tailiang GUO, Wanlong ZHANG, Enguo CHEN. Polarized light multiplexing liquid crystal grating waveguide for AR near-eye display systems[J]. Chinese Journal of Liquid Crystals and Displays, 2024, 39(5): 646

    Download Citation

    EndNote(RIS)BibTexPlain Text
    Save article for my favorites
    Paper Information

    Category: Research Articles

    Received: Jan. 25, 2024

    Accepted: --

    Published Online: Jul. 8, 2024

    The Author Email: Wanlong ZHANG (zwl@szu.edu.cn), Enguo CHEN (ceg@fzu.edu.cn)

    DOI:10.37188/CJLCD.2024-0036

    Topics