Holographic Optical Elements for Augmented Reality: Principles, Present Status, and Future Perspectives

Abstract

Holographic optical elements (HOEs) exhibit several unique properties in arbitrary wavefront recording and extraction. Versatile recording mechanisms and material availabilities further expand their design flexibilities. Augmented reality (AR) displays are emerging and transforming daily life. Applications of HOEs in AR have harvested numerous fruitful evolutionary and revolutionary progresses. Herein, the basic operation principles of HOEs are elucidated, recent advances in AR systems are reviewed, and their future perspectives are discussed.

Aberration‐free pupil steering Maxwellian display with wide‐view broadband polarization converters

“…Our proposed system uses a polarization‐dependent lens coupler fabricated through cholesteric liquid crystal (CLC) polarization holography 18,19 . Like traditional CLC, the CLC lens coupler only responds to one circular polarization and transmits the other.…”

“…Our proposed system uses a polarization-dependent lens coupler fabricated through cholesteric liquid crystal (CLC) polarization holography. 18,19 Like traditional CLC, the CLC lens coupler only responds to one circular polarization and transmits the other. The patterning method of CLC is photoalignment polarization holography that uses two beams with left-handed circular polarization (LCP) and right-handed circular polarization (RCP) to form the spatially varying linear polarization patterns.…”

Novel polarization‐dependent combiner for wide field‐of‐view glass‐like near‐eye displays

“…Figure 2 shows a typical configuration of free space AR system with diffractive combiner. 6 The system usually has a pupil-forming design. The image is first projected to the space by a relay optics, and then the diffractive combiner delivers the intermediate image to the viewer's eye.…”

“…Usually, the diffractive type free space combiner is realized by holographic optical elements with imaging capability. 6 Based on different system designs, the computer-generated image is presented to the designed depth or infinity at an off-axis incident angle. The FOV of the system is dependent on the viewing angle of the combiner lens and system design.…”

Enlarging the Eyebox of Maxwellian Displays with a Customized Liquid Crystal Dammann Grating

“…To tackle VAC, plethora of methods have been proposed, including but not limited to multi-focal plane displays [4][5][6], varifocal plane displays [7,8], integral imaging-based displays [9,10], holographic displays [11][12][13], and Maxwellian view displays [14][15][16][17][18]. Among them, Maxwellian view is a special display to bypass this VAC issue by providing a very large depth of focus.…”