Hologram. It is a photograph made with laser light and printed on a sensitive plate or film that has the peculiarity of producing objects in relief. The image seems suspended in space. And if you move the hologram, you see the image from a different perspective, just like when you move in front of a real object. They are so convincing that it seems that they can be taken by hand.
Summary
[ hide ]
- 1 Principle of operation
- 2 Elements that compose it
- 3 Applications
- 4 Source
Operating principle
Things are seen because they “reflect” light to the eyes, which detect it. The realism of the hologram is due to the fact that it constitutes an exact record of the light waves reflected by the object. When the image is reconstructed, it reflects light exactly like the original object, giving the hologram a very compelling sense of reality. The light from the hologram that the eyes perceive is the same as that which they would perceive before the real object.
Component elements
Holography is a photographic process in which lenses and mirrors are used to direct and focus a beam of laser light. Laser light is used because of its properties: spatial and temporal coherence (light that travels in an orderly fashion), and extremely monochromatic.
The image of the object is recorded on a plate covered with a light-sensitive chemical emulsion; It is exposed to both direct laser light (reference beam) and light reflected from the object (light containing information on the “shape of the object”).
At the points of the emulsion where the two beams coincide, chemical changes take place that register the image of the object. Normal photography also registers the image through chemical alterations , but in this case only the light is kept with the information of the photographed object, this being captured in a single plane.
Applications
Holography is now in a phase similar to that of photography around 1900. It would not be uncommon for you to be able to take holographic snapshots, read holographic magazines, and watch relief images on television in the next decade . At the moment you can already see holograms in galleries and exhibitions and compare them in the form of posters, or jewelry and even see them printed in books and magazines.
A limitation of holography is that the image is always life-size; therefore, it is impossible to reproduce by this procedure objects larger than the largest of the plates (about one square meter).
A hologram can be a very striking announcement; Using a special process, holograms can be printed on silver plastic. They are used to make book and record covers and even to wrap candy. Printed holograms are not as sharp as originals.
