How Hologram can be made ?

The basic principle of holography is the lasers technology. The technical logic to use the lasers instead of regular white light in holograms is the difference in their physical property.

Laser light are coherent in nature. As when these waves are interfering, they can create constructive interference or destructive interference, depending on their relative phase.

Two waves are said to be coherent if they have a constant relative phase. In laser beam all light waves are of have the same wavelength so they will bend in the same way and will vibrate at exactly the same time.

As if we pass the white light through prism rainbow colors appear because different colors of light have different wavelength so will bend differently. But if laser light is passed through prism the entire beam bends together.

Holograms are produced by using a powerful beam of laser light. A special lens splits this beam into the exactly same two beams. One beam is referred as object beam and another is called reference beam. Object beam is directed at the object, whose hologram has to be created, and its image is being captured.

Light waves reflected from the object form a specific pattern which is recorded on special holographic plate. Meanwhile, the reference beam is directed at the same holographic plate with the help of a mirror. The interference property of light waves creates the merging of two waves on the surface of the holographic plate portrait with the three-dimensional image. The final outcome is that the entire light field reflected by the object is being captured.

Illumination of the object is very crucial to get the sharp images. As the laser beam projected on the object single beam get split into two beams. Reference beam is directed by mirrors and spread by lenses to illuminate the object.

The laser lights the object, then reflected and hits the holographic film or plate positioned in front of the object. The second part of laser beam, called the reference beam, is directed by mirrors and lenses to illuminate the film. When the two splitted laser beams meet at the film, they constructively interfere (like collision which enlarges or amplifies size of beams) and record the hologram.

 In holography, this wave intensification exposes the holographic film. After exposure, the holographic film is developed in the similar procedure of black and white photography. After this process film is left for getting dry. Now, the hologram is ready for viewing. This series of steps brings a "Master" hologram which is viewed by laser beams only.

 This laser beam master hologram can be re-created into white light viewable holograms by two step process. First, the laser-viewable Master hologram is created. Then, a subsequent hologram is created from the projected pseudo image of the Master hologram. This hologram can be viewed in white light.

The fascinating thing in holography is that holograms record the image of the object onto the whole piece of film. If we cut the film in half still whole picture can be viewed. Making of 3-dimensional holograms involve lots many steps but the basic principle behind them is the laser based technique.

The basic things required to make holograms are a large stable table with a laser light, mirrors, lenses and other optics. The special table is composed of a large mass resting on a vibration isolation system to reduce any movement. Any small moment can destroy the whole hologram because hologram works on recording the light waves.

Holography has given a vast creative opportunity & potential for new visual realities. It shows the new line of artwork for its artists to produce masterpiece that would be impossible through any other medium. In today’s era holographers are utilizing advanced laser techniques with diverse art forms that results in an entirely new level of artistic expression.