What is a Hologram?

A project log for Holographic Wavefront Cylindrical Display

A 360-degree cylindrical display driven by Holographic Wavefront Projection Principles

andrew-kadisAndrew Kadis 06/14/2021 at 07:530 Comments

There is a large degree of confusion with what is and what is not a Hologram. The term has come to mean a wide-gammut of ghost-like images floating in the air in popular-culture (such asPrincess Leia's 'Holographic' message).

However, the author might be suprised to learn that Holography is actually an extremely well-understood, mature field. Holography is the process of recording, generating and displaying wavefronts (or lightfields). Moreover, Holography is not a recent development, Dennis Gabor was awarded the Nobel Prize for Holography in 1971, and its appliclications are widespread, as seen from the ubiquiotous holographic film on the back of credit cards and passports.

Holography offers the Ultimate Display technology. For a perfect Hologram, the difference between a synthetic and real object is indistinguishable. This can be seen in the animation below, where the entire complex wavefront of several holograms can be captured in a single hologram of the scene.

In this project, we are utilising CGH (computer-generated holography), a process where a holographic wavefront is generated directly from synthetic data. This allows us to produce a wavefront which is suitably distorted to allow our display image to be projected through the perspec waveguide and onto the surface of our transparent display.