Fiber-optic Communications :: Fiber-optic essays

     In 1987, both Eli Yablonvitch and Sajeev tin got together to address research that both had previously discovered. Eli Yablonvitch was an electrical engineer at cost Communications Research in Red Bank, New Jersey. Yablonvitch was k without delayn for refine a laser that would become a mainstay of fiber-optic communications. Sajeev John is a Harvard graduate student who worked on a thesis excite by Philip Anderson of Princeton.      The two agreed that the name of their idea should be called a photonic band gap. Phontonic crystals have the regular lattice body structure of natural crystals. Their designing is to try and trap at large(p) without destroying it. The trick is to not kill the photons provided to tame them, by allowing combust out when you want. Microchips are made of semiconductors and a semiconductor is a band gap. A band gap makes is contingent to control the flow of electricity in a chip. In auberge to make light chips, you need the photonic equivalent of silicon a temporal that can trap light. You need a way of trapping the light so there are no escape channels, says John.      It was until 1997, when European investigators practise in trapping light in a random material. Diederik Wiersma and his colleagues utilize a powder of gallium arsenide. The laser could not penetrate a layer of powder even when the layer was less than a hundredth of an inch thick. It was indeed the very first time that anyone had trapped light, nevertheless as they knew, microchips cannot be made out of powder.      Yablonovitch was in his office on day in October 1986, I started drawing crisscrossing lines, and everywhere the lines crossed I put a heavier mark. Before I knew it I had drawn a checkerboard. And then I said, Well, I might as well do it in three dimensions. This later became known as Yablonovitchs constantan moment. He realized that what he had drawn was a c rystal structure that might trap light through interference. Interference happens when two light waves of the same wavelength meet.      The Bragg reflection is when light waves pass through one horizontal but is reflected back by the next plan. All waves that interfere constructively intensify the reflected light. Yablonovitch found that if you could design a crystal that Bragg-reflected light now which direction is was coming from, you would have built a trap.