Photonics communication [communication application of nano technology]


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Photonics communication [communication application of nano technology]

  1. 1. Photonics Communication ---Routing information at the speed of light A PAPER PRESENTED UNDER THE TOPIC Photonics Communication [Communication Application ofNanoTechnology] By:K. Jayaraj Yadav, IIIB.Tech,ECE & Lavanya, III B.Tech, lavanya@gmail.comSIDDARTHA INSTITUTE OF SCIENCE AND TECHNOLOGY
  2. 2. NARAYANAVANAM ROAD,PUTTUR, CHITTOOR DISTRICT.Abstract: fast and electrons are heavy and slow and never the twain shall meet”. In this Photonics communication Mankind always sensed the milestones of science photons play the prominent role unlike in wonders. Designing of things and applications that The wave length of light is of a few hundred nanothe humans may not even dream of had become the meters, where as our nano sized particles is of a fewultimate aim of the scientists and researchers. Here, nano meters so that we can control the light usingwe present one of such creative and awesome nano sized particles which is a very interesting thingtechnology that emerged as a landmark in the field of in communication. In this communication method weCommunications. directly pass the message signal through light without converting into electrical or any other signals that is Nanotechnology deals with the study of we are replacing the lazy electrons with morenano sized particles. With the study of nano size prominent photons.particles, devices and composites, we will find waysto make stronger materials, detect diseases in the If we can implement nano technology in photonicsbloodstream, build extremely tiny machines, generate communication we can transmit information within alight and energy and purify water. The most fraction of a second for that matter with in no time.fascinating application of Nanotechnology is that we By just using Pico joules of energy, we can switchcan transmit information at thespeed of light more parts in a few hundred Pico seconds of time. So thisefficiently through Photonics communication using is both incredibly fast and also incredibly sparing inPhotons. terms of energy usage. In this unique paper, we aim to explain how In a single statement, our innovative paper dealsnanotechnology is going to play a key role in with the concept of Photonics Communication,Electronic Fields. which holds the key in the application of The main objective of this paper is to Nanotechnology in Communications. To beimplement Nano technology in optical clearer, our concept delivers similar experiencescommunication. Photonics communication speeds up to that of Hollywood Movies……. :Dtelecommunications by replacing Electronics with Contents:Nano optics. Even though we have severalcommunicating methods like Electronic Nanotechnologycommunication, the main reason why we have to gofor photonics is “Photons are light (mass less) and Manipulating Light with Crystals: 2
  3. 3. Getting hooked on Photonics can also built. Nanotechnology puts the power of creation in human hands. Controlling light: Photonic band gaps Einstein tells us nothing moves faster than Nano-Lasers light. In fact, it is so fast that as you approach the Applications speed of light, time it itself starts to slow down. (Now that’s fast.) So when you want your email or your fax Disadvantages to get to somebody as soon as possible, what you really want to say is “get it there at the speed of Conclusion light”. That is possible with our Photonics communication.NanoTechnology: Tele communications utilize some of the various forms of light (radio waves or micro waves, The industrial revolution, electricity, for example) to throw information from one spot oncomputers, Internet and now the next big thing is the earth to another. With the billions of informationNanotechnology. Technically Nanotechnology is flying over our heads every split second or passingdefined as an anticipated manufacturing technique by below us in an optical cable, the whole world seemswhich one can be given thorough and inexpensive to be full of our thoughts. So full, in fact, that it takescontrol over the structure of matter. These structures a monstrous network of electric devices, cables andare known as nanostructures. The term computers to keep it all sorted.Nanotechnology was first introduced by RichardFeynman in 1959 and K Eric Drexler popularized it And sorting takes time. Even with the bestin 1986 in the book „Engines of Creation‟. electronics today sorting digital signals is not instantaneous, and every device, cable, or computerIt is also defined as the ability by which we can slows down the flow, even as it‟s doing its appointedarrange atoms by given each its place and thus forms task of straightening all the signals out. The one thatthe structure in nanometer scale. Nanotechnology does all the work without taking any time at all is thedeals with matter at atomic levels. The term nano is perfect device. An all-optical router that could routederived from Greek word dwarf. Here it refers to one the information without converting it from light tobillionth of a meter or (10-9). electricity is said to be the perfect device. The perfectThe central thesis of Nanotechnology is that almost device can be constructed using Nano technology inall chemically stable structures that can be specified Photonics. 2
  4. 4. and the science of manipulating such pieces of light is known as photonics. Getting hooked on Photonics: A photon is the smallest unit of light andManipulating Light with Crystals: doesnt really have a shape or size and mass. They are the building blocks of light and they travel normally As our technology still seeks to increase the in big groups. The information super highwayspeed at which information travels, the scale gets requires orderly photons for informationglobal and we find the information super highway. transmission. So, orderly photons have to be madeAlthough the information super highway has often before they can be used as signal carriers. The trick isbeen used as just another name for the internet, it also photons cant really carry anything (as they aredescribes the vast network of optical and electrical weightless) so they are not the messenger, they arecables now used to carry information. Nano also the message. By varying the number of photonstechnology is set to take the next step and improve we can form a code of high and low pulses. When wethe highway again. work at the nano scale, we rarely encounter large This over complicated, axed-out scene could mobs of photons instead; we have to deal with a fewuse some simplifying. Crystals designed on the nano photons at a time. If our nano-crystal accidentallyscale could replace electrical routers by directing the stops just one of the photons, we have immediatelylight itself instead of first converting it into electrical lost most of our information. Stopping light issignals. The fiber-optic cables we use to carry ridiculously easy. Photons love to be absorbed by justinformation are potentially capable of transferring about anything. And those things that don‟t absorbdata at 10 to 40 Gbps. But most electrical routing light usually reflect it. Thus the photon messengeroccurs at less than 1% of that rate if we transfer to an must face getting either sucked up or bounced.all-optical router we could route most data packets in Controlling where photons are absorbed and whereless than 1 trillionth of a second, pushing routing they are deflected is the business of photonics and thespeed till it can handle the full capacity of the fiber- concern of all nano-scale optical devices. Most of theoptic cable network. time, we want those photons deflected as a means of moving information along a path, bouncing photons Before we can look at the details of how to their final destination. In order to do that we createsuch an all-optical router would work, we need to and check the IDs for the photons.look at the nano- scale pieces of light that our crystalswill be dealing with. These pieces are called photons Wavelengths: Creating nano-size IDs 3
  5. 5. The photons can be considered as a wave electrical device with a quicker optical one the samebecause they are vibrating and they can be considered old design can be used to generate ideas for the newas particle depending on the situation. Photons have one. To get semi transparent structures, we have todetectable vibrations. In fact the length of the space it add just enough of the right impurities to our nanotakes for them to go through one cycle of vibration crystals. These semi transparent structures can bedetermines the wavelength of a distinct bunch of used to filter the photons. Since different photonsphotons. Moist of the light we dealt with as a wave have different wave lengths, by varying the geometrylength of few hundred nano meters. And it turns out of the nano crystal, we can change which energies getthat any nano-crystal router is going to have used the stopped by the opaque part of the crystal and thatwave lengths of photons as a way to identify them. pass through the transparent portion.The nanoscopic crystal identifies different To understand controlling of light much better,wavelengths of light by responding to how they imagine a large bowl with the marbles spinningtravel. In fact different wavelengths of light travel at around inside. Here the marbles are our photons anddifferent angles when they are passing through a the bowl is the crystal.medium. Optical communication is a pretty exclusivenight club. Usually we allow only 1500 nano meterwavelength into the party because it‟s thetelecommunications standard wave length. So if The fastest moving photons spin around nearcrystal-based router s specifically designed to the the top, the slowest photons spin near the bottom and1500 nano meter wave length, it can be integrated most of the photons spin somewhere between. Now ifinto the internet. Its important to note that different we put some putty in a circle around the middle ofmaterials and crystal designs can be specifically the bowl, the marbles that want to spin around at thattailored for a specific wavelength and only this level either get stuck in the putty or bounce to higherspecific wavelength excluding all others. That is if or lower parts of the bowl-and the marbles already inthe photons don‟t have the 1500nm ID, they cannot the high or low sections cant cross the putty that iscome into our communication system. the putty functions as a band gap. It separatesControlling light: Photonic band gaps photons into groups that have different levels of energy as shown in the above figure. Photons and electrons don‟t have a lot incommon but similar technology is needed to Now we introduce the concept of photonicmanipulate each of them. When we replace a slow band gaps. The photons that have a particular wave 4
  6. 6. length have to travel within the photonic band gap We are insulating light of a specificrestricted from the surrounding material. We can wavelength to be guided through our nano crystal.create these band gaps in one of the two ways The above figure shows a top view of a photonic crystal. When the light approaches the turn in the  By exploiting geometric abnormalities in the crystal, it bends to follow the path. The apparent crystal bending and spreading of waves can be used to  Using impurities in the crystal control the light. By exploiting the geometric abnormalitiesin the crystal, we can create distinct energy levels inthe band gap so that some photons may travel Nano Lasers:through them. Some photonic crystals are grown thesame computer chips are made. We can create a Along with routers, modern communicationhoney comb pattern in the crystal by etching opaque systems also need repeaters for the purpose ofcircles into each 2-D layer, spacing them at regular amplifying the fading light signals. To do that weintervals. As we build up the layers with the circles have to construct Nano lasers. The photonic bandalways in same places, the circles become large. The gaps also called optical cavities play a crucial role inplaces where the rods are absent are empty spaces. constructing Nano lasers.The chemical properties of these rods shape thephotonic band gap. Light won‟t travel through therods. Now, by removing enough rods we can makenano-size spaces to allow the light. The geometricconfiguration is shown in figure. When light enters an optical cavity the photonic band gap keeps the light bounce back and forth in the cavity- gaining energy, tightening into a coherent beam. To get the laser effect a gain medium has to be placed in an optical cavity. When photons enter into such a medium they get amplified and they provide complete information. To make a Nano laser, a photonic crystal is used to create a cavity thats almost as small as the 5
  7. 7. wave length of the photons. This cramped space upon another hole, ending up once again in the otherforces the photons to travel in nearly parallel lines, half of the bowl. These holes allow a few trespassersuntil the intensity of the light reaches the theoretical across the border. Photons never cross directly butlimits. We have to provide a small electric current to they can go to the intermittent level and then tom theburst out of the laser. other side. So these levels are said to be the little wrinkles or folds that led photons cross over. Most of Thus by using Nano laser we can amplify the time, these levels are hard-wired into the crystalour information signals. such as additional photons. By regulating thoseOptical Switching: Nano defects to the photons, we can make an optical switch that can turn on and off by shining a light at it.rescue! So we are able to construct an optical Being able to form different paths for switch.photons, we must be able switch between those parts.That is we have to “flip the switch” in order for a Making the switch: Photons on a nano-nano optical routing device to work. So we have to highwaysee the photonic band gaps in another way. We willlook at the bowl of marbles once again. The putty Researchers at Cornell University havethat separates the top and bottom halves can be already developed some of the nano technologydivided into number of different sub energy levels for needed to create an all-optical switch. Now, we willour convenience. Next we make small holes in the go deep in the manufacturing of optical switch. Theputty layer that allow our photons to move freely photonic equivalent is called a “ring –router” and isbetween the two halves. All of this is brilliantly pictured as below.illustrated in the following figure. Now, if there were two lines of putty spaceda bit apart from each other and holes in each of thoselines, a photon can pass into the space created by thetwo lines of putty and then roll around until it came 6
  8. 8. The ring router has intermittent levels in its light.photonic band gap and we can manipulate the levelsby introducing the photons of the properwavelengths. When the right beam of photons comesalong, the router changes its task instead of allowinglight to zip around in it and go through it; it absorbsthe new wave length or passes it of in anotherdirection. The following figure shows how such aswitch might work. Magic with Mirrors: Mirrors are a handy, easy way to direct light around and they control the information super highway. Reflecting large portions of light beam is pretty easy. When we change the direction that mirror faces, we change the direction that the information flows. While it doesn‟t get the details sorted out, it does move a lot more data around than the photonic crystals could by themselves. Notice that there are two beams we have to Combining these two techniques to provide a more keep track of- well-rounded and versatile router. We will probably have to settle for one of the many other ways to  The signal beam (the one that move mirror-to beam-steer. The following figure either gets blocked or passed shows a fairly tiny mechanical solution: 256 mirrors through the router). on a few square cm of Silicon.  A switch beam (The one that turns the ring router on and off). So we have our nano routers which are extremely quick and they route nano size portions of 7
  9. 9. Micro machines are using electrostatic force to regulate the angle of mirrors. Applications: • Lighting • Information processing • Metrology • For communications between spacecraft, including elements of a satellite constellation • For inter- and intra -chip communication. • Laser material processing Using electrical pulses to move the mirrorsprovides even final control and allows faster beam- • Two solar-powered satellites communicatingsteering. optically in space via lasers Light steering: Nanotechnology at thewheel: Disadvantages: Aiming a mirror at the nano scale requires  Waveguides and fibers are harder to useprecise control of tiny electro mechanical devices. than wire.Pushing or pulling on a mirror adjust the angle atwhich light bounces off, even small changes in  The components are more expensive.angle can lead to big differences in the final  Spurious reflections are much moredestination of beam of light. To tightly regulate the troublesome.angle of a mirror on the nano scale, we have tospread out super tiny electro mechanical devicesaround its space. So for the implementation of thisNanotechnology is essential. Researchers at Boston 8
  10. 10. Conclusion No matter which type of mirror-position indevice we would like to use, the final step is inincluding it with the nano-router is fairly simple i.e.,we use the mirror to direct the information in theform of light thus speeding up ourtelecommunication. At the end, the nano-router‟suse of mirrors will probably be limited to bulktransmission of data, photonic crystals are faster forsmaller chunks of information.References:  Nanotechnology  Nothing But the Vast Internet………….   9