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The holographic technique was originally developed by Dennis Gabor for which he won the Nobel Prize in 1971. The method he innovated proved instrumental in improving the functioning capacity of electron microscopes and still very much in use in electron microscopy. As far as commercial exploitation of the technique was concerned, (for use in optical holography), it had to wait till the invention of the laser technology in the 1960. The advent of laser technology enabled the making of optical holograms that recorded and stored 3D images. With the passage of time the manufacturing process became more and more refined. Nowadays, holographic labels and stickers are made in different formats-transmission holograms (holograms using rainbow transmission technology are the latest refinement), reflection holograms, and Specular holograms. Originally, the holographic method incorporated the use of high frequency lasers that were expensive but presently diode lasers are used for making almost the entire range of holograms. The Holographic Technology: The holographic technique makes possible the recording of a light field that is produced as the result of reflection of light rays from different objects. Thereafter the light field is recreated in the absence of the original light source or sources. The holographic technology is to some extent akin to the system of sound recording where the sound field produced by resonating objects (musical instruments for instance) is programmed in a manner for reproduction later on. A hologram is made when a light flash light up a scene and the imprint on the recording medium is captured. Additionally, some part of the light beams called the reference beam must be directed upon the recording surface or medium. Lasers invariably serve as the light source for recording holograms and they must be of prescribed wavelengths. Much like the photographic procedure, holographic images have to be recorded in a dark room within a specific timeframe (exposure time). The exposure time is monitored using an electronic timer that automatically beams the laser rays for a prefixed time period and then shuts it off. A somewhat improved arrangement for recording and capturing a holographic pattern comprises directing the laser beam on the recording surface via a number of intervening mediums that alters the beam in various ways. A beam splitter is the usually the integral intervening element used to bisect the principal beam into two similar beams going in two different directions. An interference pattern results when two distinct laser rays falling on the recording medium intersect with each other. This pattern, which is embossed on the medium is the raw or unrefined version of the hologram design that’ll be ultimately printed on the sticker or label. Of the materials that serve as the recording element, a highly concentrated silver halide film is extensively used for capturing images with a very high resolution. Vikas Bhatnager is a professional packaging expert. Dealing with anti-counterfeit measures, he has been contributing posts on holography for Lasersec India that have been manufacturing different types of hologram stickers and labels (2D/3D stickers, aluminium foil stickers, roll-ons, holographic paper labels and so on) since a decade now.
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