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Photonics Lasers, fiber optics, and 40 000 jobs. There are expected to be 40 000 jobs in photonics in the next couple of years, but what is it? It's light. And you can do amazing things with it. From downloading a full length movie in a matter of minutes, to using photon lasers to manipulate individual atoms, photonics is tagged as being the next big thing in science. New research into holographic crystals might vastly increase the amount of information we can store in a small space. You wouldn't think that the latest photonics research would involve spiders! Information about study & careers in photonics. Background Notes A brief synopsis of each of the biotechnology items in our shows and links to our references. Yushan Yan, a researcher at the University of California, has discovered a way to turn spider silk into the worlds finest optical fibres. For such a high tech result, the method seems ridiculously simple. Yan glued a length of spider web between two bits of cardboard, then dipped it repeatedly in a solution of tetraethyl orthosilicate. Once the silk was well coated, it was fired at 420°C. At this temperature all of the spider silk burned away completely, while the tetraethyl orthosilicate was set into solid silica glass. The resulting hollow glass tube is actually narrower after firing, shrinking five-fold in the furnace. Given this shrinking, if the thinnest spider silk known was used, the silk of the spider stegodyphus pacificus, a native of the Middle East and South Asia, then it could produce an optical fibre just two nanometres wide. That is more than ten times smaller than that produced by conventional methods. These ultra-fine optical fibres could be used to replace the gold wires in silicon chips, providing more reliable information transmission. They could also replace electron microscopes, which damage the samples they are scanning. The major hold-up in this technology is being able to get large quantities of spider silk. We can't synthesise it yet, and farming it is also impractical. The closest we have come is to genetically modify goats to include the silk gene. The proteins needed to make the silk are then produced in their milk. This research has its own ethical issues that many feel haven't been properly addressed. Return to top. 3D Holographic Storage Crystals It is now possible to store information in a solid block of a special type of crystal. Each bit of information is stored by a single atom, so even a small piece of this crystal can store massive amounts of information. In all computers, information is stored as binary code, ones and zeros. These are basically little switches. If the switch is on, it's a one; if it's off, it's a zero. The crystal acts the same way. The crystal is mainly made up of relatively large atoms. Because these atoms are spheres, even though they are packed as close together as possible, there are still spaces between them. Smaller atoms actually sit in some of these spaces. If you shine an ultraviolet laser onto one of these small atoms, it gives it enough energy to squeeze through into a different space. Hitting it with a laser again will make it move back to its original spot. This means that you now have a switch, which can code ones and zeros, just like in regular computer memory. The only question that remains is how to read whatever it is you have recorded onto the crystal. The cool thing about these crystals is that each little grouping of atoms bends or refracts light differently, depending on whether it's a one or a zero. This means that if you shine light through one of these crystals you actually get a 3D hologram of the information stored on it as every small atom bends it differently. Light sensors within the computer can then read this hologram like it would a disc or CD. Although these crystals exist, their creator is keeping the process of making them secret, so it may be a while before we see them in common usage. References
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