The Hologram> How holograms are made

Holograms are made using a LASER which produces a special kind of light in one pure colour. This light has the ability to transfer information about an object’s surface characteristics and location in 3D space, to a light sensitive plate. When a hologram is recorded, the complex information in the laser light reflected from the object, known as the object beam wave front, combines with a ‘plain’ wave front, or reference beam, forming microscopic fringes on the holographic plate. These are unique to every point on the plate, since each point sees the object from a slightly different position. The hologram when viewed, faithfully replays these wave fronts creating an image of the object complete with all of the surface details and their positions in 3D space.

In order to achieve this you need various optical components including mirrors, lenses and a special heavy optical table usually made of an outer layer of steel with a honeycomb structure inside to make it very rigid and stable. The optical arrangement is customised for each image shot, and this can take hours or days to accurately assemble. Once this is done a very limited number of holograms can be made of the same image. Every single component in the set up including the object needs to be incredibly still. Traffic, heat from a radiator and people talking can cause enough movement to destroy the minute fringes that make up a hologram. Even molecular cell movement will ruin the fringe structure. So a very quiet environment is essential.

Applications of Holograms >