True holographic displays reconstruct light fields to produce volumetric 3D imagery visible from all angles without glasses. Unlike autostereoscopic displays (which use lenticular lenses or parallax barriers), holograms manipulate wavefronts of light via:
- Phase Modulation: Liquid crystal SLMs (Spatial Light Modulators) or acousto-optic deflectors bend light to mimic interference patterns.
- Computer-Generated Holography (CGH): Algorithms simulate diffraction to render 3D objects (computationally intensive).
- Limitations: Small viewing angles, low brightness, and high compute requirements restrict commercial use—though laser-based and AI-accelerated holography are emerging.
Applications: Medical imaging, heads-up displays (HUDs), and futuristic AR/VR. (Note: Most “holographic” products today are actually autostereoscopic or Pepper’s Ghost illusions.)
