MIT’s Object-Based Media Group achieves 15 fps of holographic video capture

With the advent of 3D technology and the revolution which it has brought with it, it leaves no doubt in the mind about it being the next big thing. But at present, this technology is still at its nascent stage, requiring you to use bulky glasses which give you headaches and also reduce the brightness of the picture. So, what comes next? 3D without glasses!

What many of you might not have realized is that we witness 3D technology everywhere around us. The small holograms on books or postcards, are in essence tiny 3D pictures. Taking this concept further, engineers at the European research firm Imec have come up with tiny holograms created by small semiconductors. These holographic displays use the concept of constructive and destructive interference to produce a 3D picture.

Holographic displays

The basis of creating the holograms is semi-conductor technology. A silicon oxide layer is grown on a wafer of silicon. Tiny pixels are etched onto the wafer using a microscopic etching tool creating a checker box type of pattern. The portions which are etched away are about 150 nano-meters lower than the neighboring pixels, crating a stepped pattern. The wafer is then coated with a finish of aluminium to increase its reflection.

How it works

When light passes through an aperture which is smaller than the wavelength of the light, interference of the light source takes place. If the interference is constructive in nature, different shades of color is produced, while a destructive interference will create black light. This is how the entire spectrum of color is perceived.

To get the interference needed, the pixels on the wafer have to be smaller in size than the wavelength of light. The engineers from Imec have been able to create pixels as small as 0.5 to 0.5 microns wide. It was no easy task, as this was a tenth of the size of the pixels previously created by the firm. When light falls at an angle on the edges of the pixels, throughout the length of the wafer, a 3D picture is created.

Making moving holograms

Until now, the holograms created have been stationary, but Imec has hinted that moving holograms are just a couple of years away. At present, the height between two pixels is constant. To generate a moving picture, the pixels will have to be able to move in the vertical direction. This would then change the way the interference is executed in space, giving a moving 3D picture. Though it may sound very simplistic, it is far from so. This is because the movement of the pixels will be in the nano-meter range.

A major advantage of these micro electromagnetic systems is that it envisaged to be long lasting, and resistant to wear. This is because as long as thirty percent of the pixels are working, a 3D picture will be generated. This has nothing to do with the technology used, it is the optical theory behind the holograms. So, the day is not far off, when 3D holographic TVs will enter your living room!

Via: IEEE Spectrum