A Brief History Of Holograms

A hologram is created by capturing the light reflected from an object and reconstructing it so the subject appears to move relative to the position of the viewer of the hologram. This is what makes a hologram appear 3-dimensional but in fact it is not, it is a 2-dimensional representation just as an ordinary photograph.

In 1947, Hungarian physicist, Gabor Denes (known as Dennis Gabor in English) was playing in his lab with the results of pioneering technological advances dealing with the development of the electron microscope. Dennis Gabor was awarded the Nobel Prize for Physics for his discovery but he had to wait until 1971 to receive the recognition he deserved.

The discovery was made in England at the commercial lab of British Thomas-Houston who filed a patent back in 1947, however the holographic light/optical technique did not attain any commercial significance until the development of the laser in 1960. With the invention of the laser, 3-dimensional objects were then able to be made and the technique was first discovered in 1962 by two sets of teams — one in Soviet Russia led by Yuri Denisyuk and in the US, led by Juris Upatnieks.

The initial holograms required illumination using the polarized light provided by a laser which severely restricted the use of the hologram. With the development of «Rainbow Transmission» holograms, ordinary white-light sources could be used to create the 3-dimensional replication and this opened the door to using holograms in everyday life. The holograms you see on credit cards and as security tags on product packaging are of this type. The rainbow transmission technique uses a surface print on a plastic film which is then backed by an aluminum mirror-coating to provide the backlight source of illumination — this is what creates the 3-dimensional image appear.

A refinement of the rainbow transmission hologram is the «reflection» or «Denisyuk» hologram. Here a multi-color image is reproduced and a white-light source from the same side of the viewer is only needed — this removes the need for the backlight coating which increases the cost of producing the hologram.

While static 3-dimensional images can be reproduced on a 2-dimensional medium, the science fiction concept of a 3-dimensional image being projected into a space is not yet with us. The ability to replicate a 3-dimensional image into a space holds a lot of attraction for television and film but while plenty of effort has been going into creating a 3-dimensional viewing experience, the reality is that this holographic development is still science fiction and not science fact. The 2008 holographic projection of CNN reporter Jessica Yellin during the Presidential elections last year may have given the impression of a hologram projection into space but in fact there was a merging of a video feed from the reporter which was then combined with the video feed created in the studio. In other words, it was a cheat, but still gave a good indication of the possibility of 3-d holographic movies and television may be able to bring to the movie theater or your living room within the next few years.