A full‐color eyewear display using planar waveguides with reflection volume holograms

Abstract

A full‐color eyewear display with over 85% see‐through transmittance with a 16° horizontal field of view was developed. Very low color crosstalk, less than 0.008 Δu′v′ uniformity, and 120% NTSC color gamut were achieved. Waveguides with two in‐ and out‐coupling reflection volume hologram elements enabled a simple configuration that has an optical engine beside the user's temples. The reflection volume hologram elements used on the waveguides realized a small thickness of 1.4 mm for each waveguide, and an out‐coupling reflection volume hologram used as an optical combiner contributed a high see‐through transmittance of 85% due to its wavelength selectivity. However, there are technical challenges in achieving a reasonable screen size and quality color images with optics that utilize holographic waveguides because holograms have large chromatic dispersions compared to conventional optical elements such as lenses and mirrors. Approaches to overcome these issues are described.

11‐1: Invited Paper: Towards the Ultimate Mixed Reality Experience: HoloLens Display Architecture Choices

“…Various technology choices have been reported in literature to build up a waveguide combiner [3] integrating 1D or 2D EPE. Some rely on volume holography [4], based on holographic materials such as Photopolymers, Polymer Dispersed Liquid Crystals (H-PDLC), Di-Chromated Gelatins (DCG) or Silver Halides, other coupler architectures rely on reflective optics such as embedded partial mirrors or micro-prisms, and other rely on conventional binary or multilevel top down gratings couplers. We chose to use slanted sub-wavelength Surface Relief Gratings (SRGs) as high performance input and output couplers for various reasons we discuss below.…”

P‐103: Optimization of Field of View and Color Uniformity in a Holographic Waveguide Display

“…TIR condition in the waveguide: Where n is the refractive index of waveguide material, represents the total-reflection angle in the waveguide and θ B is the Bragg angle of grating which is determined by the incident wavelength and parameters of volume gratings. The relation between the Bragg angle and other parameters of a VHG can be achieved from the Bragg equation as [4]:…”

“…However, field of view (FOV) and color uniformity are the two most severe issues to constrain its application scenarios. As we know, the volume holographic grating has high selectivity of incidence angle, which limits the Field of View (FOV) [2], and high selectivity of wavelength, which causes color shift among different viewing angles [3,4]. For the final perceived image, the FOV characteristics determines the perceived size and the color shifts affect the color uniformity [6].…”

64.2: Objective LC Lens Array for a Near‐to‐Eye Display

“…For example, there are AR displays from Google (see Fig 1, [1]), Nokia [2], and Vuzix. The main idea of these products is based on a tiny projector incorporated into the glasses [3][4][5][6]. In parallel to development of the AR glasses, the possibilities of integration of a microdisplay into a contact lens are investigated [7][8][9].…”