Holograms are visual reproductions of 2-dimensional images which appear as if they are in 3-dimensional space. They generally work by reconstructing waves of light from a scene or object into an intangible, semi-transparent illusion of light. The origin of holography has greatly revolutionised different realms of the modern world, including entertainment, data storage, security features and electron imaging.
There are 2 primary kinds of holograms – transmission and reflection. The former make use of dual laser sources, object and reference beams and mirrors for printing hologram on the film and may be viewed by the same laser utilised for creating the image. On the other hand, the latter store information of a 3-dimensional image in a dense photographic emulsion placed between 2 glass plates. It requires to be viewed with bright spotlight.
In holographic projectors, laser or white light is shone through or onto holograms, which work with a single color because the pattern of interference comes from one particular wavelength of light. Therefore, holographic projectors use coloured lasers for which illuminate corresponding patterns of interference for their colours. A simple projector having light shining through flat interference pattern will create an image having 3-dimensional qualities. For achieving true 3D, the projector can make use of a spinning mirror for reflecting image to the observer. Due to generation of image by refraction through interference pattern, there is hardly any loss of light, along with efficient operation.
For projecting a hologram in the right manner, it must be pointed in the right direction. This has to be done in such a way that the audience can view the hologram properly. Suitable light construction methods and exact angles will have to be preserved as well. Currently, it is absolutely impractical for anybody to create holograms that can be viewed from all angles as well as in all kinds of light condition. Although constructing a commercial use projector is quite a complicated task, one can definitely build reflection and transmission projectors out of laser beam and bright spotlight respectively.
Nowadays, there are several products available in the market of UK which can be used effectively to create holograms. For example, companies dealing with large format printing supplies are often seen supplying holographic rear projection film. The efficiency and low carbon-footprint of holographic projectors have even made them suitable for gradual applications in smartphones, tablets and other mobile devices. This is because they can be small if required and produce very less heat. As such, their potential to be included in mobile devices, where space and power are limited, is significantly great.