Reflection Hologram Physics

Reflection holograms are highly valued for their ability to be illuminated using standard incandescent white-light sources. In a reflection optical setup, the reconstructing light source is positioned on the same side of the recording plate as the observer, reflecting off the medium to synthesize the volumetric image.

This behavior is achieved using thick-emulsion film layers. By directing the reference and object beams from opposite sides of the plate, the beams interfere to form standing-wave systems parallel to the film. This structures fine horizontal layers of micro-fringes within its thickness.

When struck by broad-spectrum white light, these layered structures act as a highly selective optical Bragg filter. They reflect only a specific wavelength (typically a bright emerald-green or gold-orange) while allowing other colors to pass through unreflected. This delivers self-filtering holographic images that can be viewed anywhere.