PLASMONICSPLASMONICS – The newer technology that enables faster world 1 K.KRISHNA MOHAN (08M61A0486) Department of ECE Mail: firstname.lastname@example.orgABSTRACT: plasmons are associated with Get ready to surface charge oscillations. Theirwitness even faster computing and frequency is almost equal to that oftelecom. Plasmonics a new light; optical frequencies are abouttechnology promises to bring this 105 times greater than therevolution by putting together the frequency of today‟s electronicbest of electronics and plasmonics. microprocessors. So light can beCurrently communication systems used to excite them on the surfaceare based on either electronics or of a material in a localized regime.photonics. However, with the questfor transporting huge amounts of The energy required to receive anddata at a high speed along with send a surface Plasmon pulse canminiaturization, both these be less than for electric charging oftechnologies are facing limitations. a metallic wire. This could allowDue to their mismatched capacities plasmons to travel along nanoscaleand sizes, it is very difficult to wires carrying information from onecobble them to get a high bit rate part of a microprocessor to anotherwith miniaturization. with a high bit rate. Plasmonic So researchers are interconnects would be a great boonpioneering a new technology called for chip designers, who have been„plasmonics.‟ Due to its frequency able to develop ever smaller andbeing approximately equal to that of faster transistors but have had alight and ability to interface with harder time building minutesimilar-size electronic components, electronic circuits that can moveplasmonics can act as a bridge data quickly across the chip.between photonics and electronics Limitations of present modes:for communication. Presently, electronics plays anKEY WORDS: important role in communication. InPlasmonics,plasmons,plasmonsters, laboratories though, photonics hasinvisibility cloak, Metametals, started replacing electronics where aPlasmontherapy,electronics,photoni high data transfer rate is required.cs,plasmonicinterconnects. Electronics deals with the flow ofWhat is plasmonics? charge (electrons). When theThe term „plasmonics‟ is derived frequency of an electronic pulsefrom plasmons quanta associated increases, the electronic devicewith collective excitation of becomes hot and wires become veryfelectrons in metals. Surface loose. Hence by the principle of “the
PLASMONICShigher the frequency, the higher the Hence plasmonics is frequentlydata transfer rate,” a huge amount associated with nanotechnology. 2of data cannot be transferred On the Investigators have found that byother hand, when the size of an creatively designing the metalelectronic wire reduces, its dielectric interface, they canresistance (inversely proportional to generate surface plasmons with thethe cross-sectional area of the wire) same frequency as theincreases but the capacitance electromagnetic wave but with muchremains almost the same. This leads smaller wavelength. Thisto time delay effects. phenomenon could allow plasmons In photonics, optical to travel along nanoscale wiresfibres are used. These transmit called „interconnects‟ in order tolight along their axis by the process carry information from one part ofof total internal reflection. The fibre the microprocessor to another.consists of a core surrounded by acladding layer, both of which aremade of dielectric materials. Toconfine the optical signal in thecore, the refractive index of the coremust be greater than of thecladding. The lateral confinementsize of the optical cable isapproximately half the wavelength ofthe light used. Hence the size oftheoptical cable is of the order of Fig.Operating speeds and sizes ofhundreds of nanometers larger than plasmonics and other devicestoday‟s electronic devices.Communication with plasmonics: APPLICATIONS : This technology has vastPlasmonic structures can exert huge applications in various fields ofcontrol over electromagnetic waves science and technology.at the nanoscale. As a result, energycarried by plasmons allows for light PLASMONSTERS – A FASTERlocalisation in ultra-small volumes CHIP:far beyond the diffraction limit of The development of chip-scalelight. To generate surface plasmons, electronics and photonics has led toit is necessary to excite the metal- remarkable data processing anddielectric interface in which the transport capabilities that permeatedielectric constant of the metal is a almost every facet of our lives.function of frequency and negative. Plasmonics is an exciting new device At the nanoscale, the technology that has recentlyelectromagnetic (EM) field of the EM emerged. It exploits the uniquewave displays the electron cloud due optical properties of metallicto its well coupling, which is not nanostructures to enable routingpossible in the case of bulk matter.
PLASMONICSand manipulation of light at the nanoshells into a promising tool fornanoscale. A tremendous synergy cancer treatment. Scientists injected 3can be attained by integrating plasmonic nanoshells into theplasmonic, electronic, and bloodstream of mice with cancerousconventional dielectric photonic tumors and found that the particlesdevices on the same chip and taking were nontoxic. What is more, theadvantage of the strengths of each nanoshells tended to embedtechnology themselves in the rodents cancerous tissues rather than thePlasmonic therapy- cure for healthy ones because more bloodcancer : was circulated to the fast-growing Fig.Nanoshell tumors. Invisibility cloak:The potential uses of plasmonicdevices go far beyond computing,however. Scientists have developedstructures called nanoshells thatconsist of a thin layer of goldtypically about 10 nanometers thick Whilst previous studies have eitherdeposited around the entire surface been theoretical or limited to theof a silica particle about 100 cloaking of 2D objects, thenanometers across. Exposure to University of Texas team has beenelectromagnetic waves generates able to demonstrate how ordinaryelectron oscillations in the gold objects of any size and shape can beshell; because of the coupling cloaked in their naturalinteraction between the fields on the environment in all directions. Theshells inner and outer surfaces, researchers used a method knownvarying the size of the particle and as plasmonic cloaking to hide anthe thickness of the gold layer 18cm cylindrical tube fromchanges the wavelength at which microwaves. They did this using athe particle resonantly absorbs different kind of material known asenergy. In this way, investigators plasmonic Meta materials –can design the nanoshells to composites of metal and non-selectively absorb wavelengths as conductive synthetics made ofshort as a few hundred nanometers nanometer-sized structures. "When(the blue end of the visible light strikes an object, it reboundsspectrum) or as long as nearly 10 off its surface towards anothermicrons (the near infra red). direction, just like throwing a tennis ball against a wall”. The reason weThis phenomenon has turned see objects is because light rays
PLASMONICSbounce off materials towards our In order to realise advanced activeeyes, and our eyes are able to circuits , there is a need for active 4process the information. modulator and components operating at Ultra-high bandwidth and low power utilisation.QUANTUM DOT PLASMONICS: Conclusion: These are the semiconductor Plasmonics is a fascinating andnano crystals. It couples strongly currently vastly expanding area ofboth photonics and electronic research, and hopefully readingproperty; these are used for making through this text has provided thesuperfast computers that can interested reader not only with antransfer data up to 10GBPS.used in overview, but also with a solidoptical applications such imaging, foundation for own explorations.solar photo voltaic and artificial Clearly, the diversity of emergingphoto synthesis. and potential applications of sub- wavelength optics with metalsFuture directions: together with successful proof-of- To develop new optical concept studies suggest that components and systems interest in the field will be soaring that are of same size as for many years to come. today smallest integrated chips. References: Plasmon sources, 1. Akmov, a.m.mukhegee. detectors, switches and 2. Albrecht, McCann J.A wires as well as splitters Creighton can be developed. 3. From the book “The Molecular switches. emerging future of Nano All frequencies of the technology” visible light must be 4. www.nanoplasmonics.com covered. 5. www.physisorg.comChallenges remaining :The dream of making all-Plasmonicdevices requires further research .