Holographic display

A holographic display is a display that reconstructs the light wavefront of a scene through diffraction, producing a three-dimensional image with continuous depth that a viewer can focus their eyes on as they would on a real object. Unlike a stereoscopic display, which shows each eye a flat image to create the illusion of depth, a true holographic display recreates the physical wavefront itself, so the image carries correct per-pixel focus cues.

The term is used loosely in marketing. Several products sold as "holographic" are not holographic displays in the optical sense: they are autostereoscopic or multiscopic displays that present a set of flat two-dimensional views, or augmented reality headsets whose optics contain holographic components but whose imagery is ordinary head-tracked stereoscopic rendering. Genuine holographic image formation is an active research topic in virtual reality (VR) and AR optics, where it is studied as a way to build thin near-eye displays that resolve the vergence-accommodation conflict.

How it works

A holographic display works by controlling the phase, and sometimes the amplitude, of light across a surface so that the diffracted light forms the same wavefront a real object would emit. In an optical hologram this pattern is fixed in a recorded medium; in a holographic display the pattern is dynamic and is produced by a spatial light modulator (SLM), a pixelated device that imposes a programmable phase shift on coherent light from a laser. The pattern itself is a computer-generated hologram (CGH), calculated for each frame from a 3D scene.

Because the display reconstructs a wavefront rather than a fixed image at a fixed plane, different parts of the picture can be placed at different optical distances. The eye accommodates (changes focus) to bring a given depth into sharpness, exactly as with a physical scene. This per-pixel focal control is the property that distinguishes a holographic display from a conventional VR or AR display, where all content sits on a single virtual image plane regardless of its simulated depth.

Holographic systems are often described by the kind of parallax they reproduce. A full-parallax hologram delivers correct views as the eye moves both horizontally and vertically, which is the most demanding to compute. Horizontal-parallax-only systems drop vertical parallax to cut the computational load, which suits the side-by-side arrangement of human eyes.

Distinction from stereoscopic and light-field displays

A stereoscopic display, the basis of nearly all consumer VR headsets, sends a separate flat image to each eye. The brain fuses the pair into a sense of depth, but every pixel is physically at the focal distance of the screen or its eyepiece optics. When the eyes converge on a near virtual object while still focusing at the fixed screen distance, the mismatch produces the vergence-accommodation conflict, a documented cause of eye strain and discomfort. A true holographic display avoids this conflict because the reconstructed wavefront carries the real focus information.

Light-field displays occupy a middle position. A light-field (or integral) display reproduces many discrete rays in different directions, approximating the focus cues of a scene without diffraction. Desktop products from Looking Glass Factory are super-stereoscopic lenticular light-field displays that show dozens of horizontal views and are marketed as "holographic," but they form images by directing rays through a lens array rather than by wavefront reconstruction. By contrast, a holographic display recreates the wavefront directly, which in principle yields continuous rather than quantized depth.

"Holographic" branding in AR headsets

Augmented reality headsets are frequently called holographic even though the three-dimensional objects they show are head-tracked stereoscopic images, the same approach used by VR headsets. The word "holographic" in these products usually refers to the optics, not the picture. Diffractive waveguide combiners route light from a microdisplay to the eye using diffraction gratings, and some are made as holographic optical elements (HOEs), thin recorded holograms that behave like mirrors or lenses.

Microsoft branded its mixed reality platform Windows Holographic and called the imagery shown by the HoloLens "holograms," but the HoloLens used diffractive waveguide combiners and stereoscopic rendering rather than wavefront-reconstruction holography. Microsoft ended production of the HoloLens 2 in October 2024 and confirmed in February 2025 that it had exited HoloLens hardware development, with no consumer successor planned; the device is to receive critical security updates until the end of 2027, and the related military IVAS program moved to Anduril Industries. Other waveguide HMDs, including Magic Leap and devices from DigiLens, use the same family of diffractive or holographic combiner optics with stereoscopic content.

Holographic near-eye displays for VR and AR

The aim of using genuine holography in a headset is to combine a thin form factor with correct focus cues. In 2017, Andrew Maimone, Andreas Georgiou, and Joel S. Kollin of Microsoft Research presented "Holographic near-eye displays for virtual and augmented reality" at SIGGRAPH, demonstrating phase-only holographic projection with per-pixel focus control. Their benchtop AR prototype reached an 80-degree horizontal field of view in a thin form, and the method could correct a viewer's own optical aberrations, such as astigmatism, in software by pre-distorting the emitted wavefront.

A 2020 review in Optica by Chenliang Chang, Kiseung Bang, Gordon Wetzstein, Byoungho Lee, and Liang Gao surveyed the field and set out the central obstacles: the limited space-bandwidth product of current SLMs, which bounds image resolution and the size of the viewing region (eyebox); the etendue trade-off between field of view and eyebox; speckle and image-quality limits; and the heavy computation needed to generate holograms in real time.

More recent work targets eyeglass-scale hardware. In 2022, an NVIDIA and Stanford team published "Holographic Glasses for Virtual Reality" at SIGGRAPH, pairing a pupil-replicating waveguide, a geometric-phase lens, and a phase-only SLM in a display only a few millimeters thick. In 2024, a Stanford group led by Gordon Wetzstein reported full-color 3D holographic AR in Nature, using an inverse-designed metasurface waveguide (grating period 384 nm, height 220 nm) about 3 mm thick together with a phase-only SLM and a learned image-formation model calibrated from camera feedback.

As of 2026 these holographic near-eye displays remain laboratory prototypes; no shipping consumer VR or AR product uses wavefront-reconstruction holography for its image, and waveguide plus stereoscopic rendering is still the production approach.

Other holographic display research

Holographic displays are also pursued outside head-mounted use, as glasses-free three-dimensional screens. The MIT Media Lab has worked on electroholography and dynamic holographic video since the late 1980s, including a system shown in 2013 that used a Kinect sensor for capture and laser diodes for output. Such efforts face the same SLM resolution and computation limits as near-eye work, which is why large, real-time, full-parallax holographic displays are not yet common products.

Companies

A few companies have worked on holographic optics relevant to AR. Akonia Holographics, a Colorado firm spun out of holographic-data-storage research, developed holographic waveguide optics for smart glasses and was acquired by Apple in 2018. DigiLens makes switchable holographic waveguides based on liquid-crystal materials. These products use holographic optical elements as combiners and should not be confused with displays that reconstruct an image wavefront.