Hologram
WHAT IS A HOLOGRAM?
A Hologram is a 3 dimensional representation of an object which can be seen without the use of intermediate optics such as goggles, glasses etc..The term "Hologram" can refer to both the encoding of the light field as an interference pattern and also the resulting image. The technique by which holograms are made is called Holography. Holography is a technique by which a light field is recorded and projected through a laser. It is based on the principle of interference and is generally made by creating an interference pattern with the use of light waves. A holographic image is visually indistinguishable from the actual object. A Hologram can produce details of the recorded object at the microscopic level.
HISTORY
In the late 1940s, physicist Dennis Gabor working in the field of X-ray microscopy with other scientists discovered Holography. The discovery was an unexpected result of research into improving electron microscopes at the British Thomson-Houston company. The company filed a patent in December 1947 (patent GB685286). The technique invented is still used in electron microscopy where it is known as electron holography. But the optical holography took place after the invention of laser in 1960. Dennis was then awarded a Nobel prize in physics in the year 1971.
HOW HOLOGRAMS ARE MADE?
Holography is a technique that enables a light field to be recorded and later reconstructed when the original light field is no longer present. This process is carried out when the hologram is recorded using a source of laser light which is very pure and orderly in its composition. A laser light is different from a normal light (Ex: the flash light of your phone). Imagine a School where the children are leaving for home, they rush everywhere in all directions which is how a normal light is, it disperses in all directions. Now imagine a soldier march or a parade where they all move in the same direction and all at a time uniformly which is how laser works. Laser light is more preferable than a normal light source for recording a hologram.
In one common arrangement (as shown in the figure) the laser beam is split into two,one is known as object beam which falls on the photographic plate passing through the object and other is known as reference beam which interferes the object beam after passing through object and creating an interference pattern. Thus the interference pattern is recorded on the photographic plate. It takes a few microseconds for the absorption, in some cases it takes less than that. This depends on the power of the laser source. If the arrangement is disturbed during exposure then the holographic image can be blurred and the hologram is spoiled.
This type of holograms are quite old and can be seen everywhere in today's world. Modern Holograms are very popular among the fields of science. Two-Dimensional representations are now converted to Three-Dimensional as you
would have watched in science fiction movies. They are mostly used in advanced laboratories where the 3 dimensional representation acts as good source of extracting information when the object is not present or is difficult to examine. Today holograms are very inexpensive and holography kits have entered the mainstream consumer market. These kits enabled teachers, students, hobbyists, researchers to make several kinds of holograms without specialized or expensive equipment. Holograms are made with modified material that interacts with molecules generating a change in moment or any other disturbance and hence acting as Sensors or Biosensors and also for the security purpose.
Holography has become an important field in experimentation and application since its beginning and has reached heights such as the Augmented Reality (AR) and Virtual Reality (VR) which are the latest additions in the technology. At last I just want to say that the Holography plays a prominent role in today's technology and the humanity will be shortly experiencing a whole new Era of Super Realistic Technologies.
Comment your Views and Suggestions:)
A Hologram is a 3 dimensional representation of an object which can be seen without the use of intermediate optics such as goggles, glasses etc..The term "Hologram" can refer to both the encoding of the light field as an interference pattern and also the resulting image. The technique by which holograms are made is called Holography. Holography is a technique by which a light field is recorded and projected through a laser. It is based on the principle of interference and is generally made by creating an interference pattern with the use of light waves. A holographic image is visually indistinguishable from the actual object. A Hologram can produce details of the recorded object at the microscopic level.HISTORY
In the late 1940s, physicist Dennis Gabor working in the field of X-ray microscopy with other scientists discovered Holography. The discovery was an unexpected result of research into improving electron microscopes at the British Thomson-Houston company. The company filed a patent in December 1947 (patent GB685286). The technique invented is still used in electron microscopy where it is known as electron holography. But the optical holography took place after the invention of laser in 1960. Dennis was then awarded a Nobel prize in physics in the year 1971.
HOW HOLOGRAMS ARE MADE?
Holography is a technique that enables a light field to be recorded and later reconstructed when the original light field is no longer present. This process is carried out when the hologram is recorded using a source of laser light which is very pure and orderly in its composition. A laser light is different from a normal light (Ex: the flash light of your phone). Imagine a School where the children are leaving for home, they rush everywhere in all directions which is how a normal light is, it disperses in all directions. Now imagine a soldier march or a parade where they all move in the same direction and all at a time uniformly which is how laser works. Laser light is more preferable than a normal light source for recording a hologram.
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| "Figure shows how a hologram is produced" |
This type of holograms are quite old and can be seen everywhere in today's world. Modern Holograms are very popular among the fields of science. Two-Dimensional representations are now converted to Three-Dimensional as you
 |
| "A Still from the movie "Iron Man-2" |
Holography has become an important field in experimentation and application since its beginning and has reached heights such as the Augmented Reality (AR) and Virtual Reality (VR) which are the latest additions in the technology. At last I just want to say that the Holography plays a prominent role in today's technology and the humanity will be shortly experiencing a whole new Era of Super Realistic Technologies.
Comment your Views and Suggestions:)
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