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Holography: Science fiction to reality

For decades, the application of holograms has been seen in Sci-fi movies and TV series. In Star Trek and Star Wars, it is common to see 3-dimensional transparent images of someone. One popular instance was the 3-dimensional image of Princess Leia pleading for help from Obi-Wan Kenobi. In most of the movies, 3-dimensional images (holograms) are used for interaction with someone who is not physically present. This technique is not only possible in science fiction, it can be implemented in real life. And it is most possible that we will be able to interact with 3D images of someone sitting far away in the near future. This is possible because of holography.

This fascinating technology is becoming very popular nowadays. It is based on the principle of the ‘optical interference phenomenon’. Optical interference is defined as the interaction of two coherent or correlated light sources with the same frequency. This can happen when two light sources coming from the same origin interact (laser). So, to record a 3D hologram of any object, interference of laser source and light from the object are recorded on a holographic screen. Then, after recording, the image can be reconstructed from the hologram by using a laser source. Laser sources generate the image at the same position in which it was placed during recording. And because of interference, we also get 3D information of an object.

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At present time, we are using holography technology without knowing that it is based on the same technology that is shown in fiction movies. One of the common applications are 3D holograms on books. On those holograms, a 3D image of an object can be seen by tilting the book. Historically, the first optical hologram was developed in 1962 by Yuri Denisyuk in the Soviet Union. It happened only after the development of the laser light source, which is the basic requirement for the development of a hologram. Firstly, this development became popular among artists. The first holographic art exhibition was held at Cranbrook Academy of Art in Michigan in 1968. After that, a number of art studios and schools were established, each with a particular approach to holography. Along with this, scientists had started research on this technique regarding applications in real life. They found it in storage systems, sensors, biosensors and security systems. As a storage system, holography technology can be implemented for storing terabits of data in a 120mm disc, which was developed around 2004 but has not been commercialized yet. As a sensor, it has been implemented for various applications like gas sensors and biosensors for diagnostic use. Regarding security systems, holography films are used in currency notes, as security holograms are hard to forge. They can only be replicated from the master hologram that requires expensive and specialized equipment.

The future of holography is going to be an interesting aspect of daily life. The research and development of this technique are not confined to any specialized field. Now, big companies like Microsoft are trying to implement this technology in their products. MSFT and Tech30 are interesting projects that Microsoft is investing in. Using this technique, holograms can be pulled, tapped and flicked away by just looking at it through special glasses called HoloLens. HoloLens is itself a computer. It understands where your eyes are pointed at, recognizes your gesture and voice and it can map your surroundings. It is not just a project: some scientists from the University of Tokyo’s Department of Complexity science and Engineering have already developed a machine called Haptoclone that can perfectly replicate an object and display a clone of it in second place, which can then be seen with the naked eye and touched with the bare hand. Plus, if you interact with the object, for example by touching the 3D image, the system effects the hologram by the force exerted by you and displays the effect made by that force.

Text: Mukesh Yadav