It sometimes seems that every week, we read of a new advance in technology that will allow the further packing of several times more information on magnetic or optical storage media. Yet despite this, the newer high-capacity optical formats like HD-DVD and Blu-Ray have not yet been enthusiastically received by consumers; a significant factor of which must be the cost of 'upgrading' due to the manufacturer's recoup of huge developmental costs in the early stages of production.
So what if someone told you that they could modify an off-the-shelf laser diode component to enable it to focus a beam down to one twentieth the size of that currently achievable using conventional optical lenses, and theoretically get 3.6 terabytes onto a DVD-size disc? Such a development feat has been reported in an article in Technology Review, which highlights the very elegant idea of using thin metallic coatings on the light-emitting edge of a conventional laser. At the correct scale, this simple modification produces a miniature electronic storm at the laser's surface that further focuses the beam down to as little as 30 nanometres. Termed an 'optical antenna', (to make the point that this avoids the theoretical diffraction limit of glass/plastic lenses), this modification could facilitate the very rapid development of cheap and reliable optical storage in the near future.
Rather than just being a pie-in-the-sky prediction, there is plenty of history to back up the potential of this methodology. Such electromagnetic workarounds to the physical glass lens diffraction limits have produced major advances in structural biology; for example, the electron microscope. There are also potential consequences for the photolithography industry, enabling the production of vastly cheaper machines to etch the minute electronic junctions of integrated circuitry, and makes possible the development of very high resolution optical laser microscopes. Read the full article here...
