8/20/12

Holography - Introduction



An encouraging development in optics are a technique known as holography. The name was derived from two Greek root meaning "a perfect record" and this phrase is very appropriate. Holography not only record images of objects that exist in the form of 3-dimensional but the picture was too colorful and it fits perfectly with the original object. Basically with holography are a form of photography, that produces a permanent record from objects on photographic plates. However, the results are different in one respect from the usual photography.

To understand the intricacies of holography, it is necessary to think of the light as a series of waves that move through space at a speed of about 300,000 miles per second. Ordinary white light is formed on a variety of different frequencies; frequencies that correspond to different colors. Different frequency waves are not in phase (should we say, in steps) and they tend to interfere with each other at random.

How It's conducted?

In the holographic interference arising between wave controlled and utilized in such a way with the goal of recording the image of a permanent rather than the target object. In the equipment most commonly used in recent years, which recording the light objects equipped with a laser beam. Laser light are monochromatic is, made ​​of light waves that fall within a very narrow frequency range and moving in harmony with each other. The resulting light beam is said to be in a coherent manner. It is used in holography is not to abolish but to control interference.

A photographic plates, which usually consists of a glass slide coated with photographic emulsion, is used. The laser beam is not through the lens before the photographic plate and split into two parts. Unity beam is directed at the object whose image is to be recorded first and then reflected from the object to the photographic plates. The second beam, called the reference beam, focused directly on the plate.

Because of the light reflected from objects to unity plates, the beam is out of step with the reference beam. Changes in the intensity also occur. When the two beams meet in the photographic emulsion plates, they interfere with each other. Interference effect was recorded in the silver particles in the emulsion as a pattern placement and density range. This recording is called hologram associated with the photo negative in regular photography, but does not present a recognizable image.



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