How to make a hologram

Alexandre Escarguel, Senior Lecturer, Laboratory of Physics of Ionic and Molecular Interactions (PIIM)

Classes are open from the fifth grade onwards

When two coherent laser light beams meet, an interference pattern is created, which is the basis of all holographic techniques.
3D photography, as surprising as it may seem, is as old as "flat" photography (photography as it is widespread today, in two dimensions). The principle of 3D photography is simple: it consists in reproducing the conditions of binocular vision. Indeed, it is because we have two eyes (and a brain!) that we see in relief. The right eye and the left eye do not see exactly the same thing, one sees a little more to the right, the other a little more to the left. The brain then processes the information it receives from both eyes and, from the differences, it can "calculate" the relief. For photography, it will be necessary to reproduce the conditions at the time of shooting and at the time of viewing.

What is a hologram?

Since the invention of photography and film, imaging techniques had not evolved much: images were two-dimensional. They only allowed to observe the reproduction of an object from one angle. However, since the invention of holography and the advent of lasers, it has been possible to take "3D photographs": the appearance of the "holographed" object changes according to the angle from which it is viewed. Some uses of holograms:

  • Authentication of objects: holograms on credit cards, CDROM...
  • Industrial applications: micrometric deformations of objects
  • Computer science: Holographic memories
  • Artistic holography....

During this workshop, the facilitator will create a hologram using a laser in front of the students while simply explaining the basic concepts necessary for their understanding.

Register for the workshop

3-dimensional photography