تحليل و طراحي يك موجبرپلاسمون پلاريتون سطحي هايبريد براي محدود كردن بيشتر موج و طول انتشار بلندتر

چكيده انگليسي :

Analysis and Design of a Hybrid Surface Plasmon Polariton Waveguide with Higher Confinement and Longer Propagation Length Seyyed As ad Amirhosseini s a amirhoseyni@ec iut ac ir Date of Submission 2012 9 18 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Reza safian r safian@cc iut ac irAbstractPhotonic circuits can transmit data signals in a much higher speed than conventionalelectronic circuits However miniaturization of photonic circuits and devices is hinderedby the existence of light diffraction limit A promising solution to this problem is byexploiting plasmonic systems for guiding and manipulating signals at optical frequencies Plasmonic devices are generally composed of noble metals and dielectrics whoseinterfaces can confine surface plasmon polaritons a hybrid wave that is free of diffractionlimit Plasmonic waveguides and devices are serious contenders for achieving next generation photonic integrated circuits with a density comparable to the electroniccounterpart Until now variuos kinds of plasmonic waveguides with the ability to achieve highlydensity optical circuits were proposed However only hybrid plasmonic waveguide because ofhaving long propagation length and high mode confinement received much attention betweenresearchers This thesis proposed a new class of hybrid plasmonic waveguide that will beinvestigate throw theoritical and simulation steps We present a novel hybrid plasmonicwaveguide which consists of metal cap placed on the SOI rib with a hole in Silicon layer underthe metal which has a semi circle interface at its bottom With this idea we incorporate both ideaof using circular geometry to have very tight confinement and long propagation length and SOI ribplatform to ensure compatibility to CMOS technology simultaneously By introducing this newlow index region the present hybrid plasmonic waveguide provides a very high power density inthe region of low index hole due to the field enhancement resulting from the effects of electric field discontinuity and surface plasmonic The simulation results show a very small effective modearea in the proposed structure It will be shown that this novel structure also has very small decoupled separation for two parallel identical waveguides which is helpful in realizing high density photonic integrated circuits As it will be revealed our proposed hybrid plasmonicwaveguide can confine light in the range of 0 006 and have long propagation length in the range ofmilimeter simultaneously It has been shown that covering the metal strip with two thin layers oflower index material can be a way to reduce the loss and increasing the propagation lengthsignificantly However the tradeoff is that it also increases the mode size Therefore to solve thisproblem to some extent a hybrid waveguiding mechanism was proposed recently In thesestructures the mechanism consists of a high index contrast dielectric waveguide placed close to aplasmonic structure In this regard one of the important structures that attracted a lot of attention isthe hybrid waveguide consisting of a high index medium separated from a metal surface by a lowindex spacer It has been shown that this waveguide can have a good confinement and propagationdistance at the same time Other kinds of hybrid plasmonic waveguide for TM polarization can becreated by placing a metal cap or metal plate on top of a SOI silicon on insulator rib waveguidewith SiO2 on the surface or by incorporating air nano trench at the interface of metal and Siliconlayer Keywords Surface plasmon polaritons Figures of merit SOI substrate coupling length

امير حسيني، اسعد

تحليل و طراحي يك موجبرپلاسمون پلاريتون سطحي هايبريد براي محدود كردن بيشتر موج و طول انتشار بلندتر

زير لايه SOI , عدد شايستگي , ضريب كوپلاژ