Color gamut characteristics of diffractive-light guides of near-eye augmented reality glasses

Ching-Cherng Sun; Wen-Kai Lin; Tsung-Hsun Yang; Zih-Fan Chen; Chi Sun; Wei-Chia Su; Shao-Kui Zhou; Yeh-Wei Yu; Tsung-Xian Lee; Chih-Yuan Cheng; Shiuan Huei Lin

doi:10.1016/j.isci.2024.110023

Color gamut characteristics of diffractive-light guides of near-eye augmented reality glasses

iScience. 2024 May 18;27(6):110023. doi: 10.1016/j.isci.2024.110023. eCollection 2024 Jun 21.

Authors

Affiliations

¹ Department of Optics and Photonics, National Central University, Chung-Li 320317, Taiwan.
² Department of Electrophysics, National Yang Ming Chiao Tung University, HsinChu 30010, Taiwan.
³ Graduate Institute of Photonics, National Changhua University of Education, Changhua 50074, Taiwan.
⁴ Graduate Institute of Color and Illumination Technology, National Taiwan University of Science and Technology, Taipei 10607, Taiwan.

Abstract

We delve into the distinctive color gamut characteristics resulting from color dispersion of surface relief grating (SRG) and wavelength degeneracy of volume holographic optical element (VHOE) in a diffractive light guide. While a laser-like spectrum achieves an impressive 194% sRGB color gamut for both cases, it proves unsuitable for VHOE light guides due to limitations in breaking the field of view (FOV) of the display. Conversely, a broad-band light source, such as LEDs, offers continuous FOV but reduces the common color gamut to 50% sRGB. We then present a newly designed VHOE light guide capable of achieving the common color gamut of 130% sRGB using two multiplexed holograms of each color, closely matching the 133% sRGB achieved by an SRG light guide. This article presents the first theoretical methodology to elucidate color performance of diffractive light guides utilizing VHOEs with holographic multiplexing, affirming their suitability for crafting high-quality near-eye display.

Keywords: Computer science; Engineering; Optics.