Download or read book Engineering Optical Antenna for Efficient Local Field Enhancement written by Tae Joon Seok and published by . This book was released on 2012 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical antennas have been widely used for variety of applications such as sensitive photodetection, efficient light emission, high-resolution imaging, heat-assisted magnetic recording, and surface-enhanced Raman spectroscopy (SERS) because they can capture and focus propagating electromagnetic energy into sub-diffraction-limited areas and vice versa. However, widespread application of optical antennas has been limited due to lack of appropriate methods for uniform and large area fabrication of antennas, as well as difficulty in achieving an efficient design with small mode volume (gap spacing
Download or read book Optical Antennas written by Mario Agio and published by Cambridge University Press. This book was released on 2013-01-03 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: This consistent and systematic review of recent advances in optical antenna theory and practice brings together leading experts in the fields of electrical engineering, nano-optics and nano-photonics, physical chemistry and nanofabrication. Fundamental concepts and functionalities relevant to optical antennas are explained, together with key principles for optical antenna modelling, design and characterisation. Recognising the tremendous potential of this technology, practical applications are also outlined. Presenting a clear translation of the concepts of radio antenna design, near-field optics and field-enhanced spectroscopy into optical antennas, this interdisciplinary book is an indispensable resource for researchers and graduate students in engineering, optics and photonics, physics and chemistry.
Download or read book Field Enhancement and Far field Radiation Using Parabolic Gold Optical Antenna written by Anupama Bhat and published by . This book was released on 2012 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical antennas are metal nano structures that convert strongly localized energy into radiation and vice versa with a high throughput. Metals are not perfect conductors at optical frequencies and their optical properties are strongly affected by the existence of Surface Plasmon Polariton (SSP) resonances. These modes are highly confined and can be controlled at the nano scale by shape and size of metals. Although the principles of nano-optical antennas have been derived from conventional antennas, but the quantitative evaluation of antennas cannot be simply scaled down for nano antennas owing to the unusual behavior of metals at optical frequencies. Since the behavior of such nano antennas is dominated by surface Plasmon resonances, a numerical solution/simulation based on Maxwell's equation is necessary to study the effects of size of nano antenna, dielectric and illumination conditions on the field. The focus of this thesis is to analyze the scattered field of gold parabolic nano-disc. The research is based on the theory of conventional parabolic dish as an efficient structure for transmission and reception of energy. The field profile of the nano-disc provides insight into the behavior of the disc with respect to directivity, gain and field enhancement. This leads to the plasmonic applications in lasing cavities, photo voltaic cells, microscopy and spectroscopy. The simulation is carried out in COMSOL MULTIPHYSICS as it incorporates the Finite Element method (FEM) to solve the equations with the boundary condition.
Download or read book Plasmonic Optical Antennas for Enhanced Light Detection and Emission written by Edward Simon Barnard and published by Stanford University. This book was released on 2011 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: Antennas are used across a wide range of frequencies in the electromagnetic spectrum to concentrate wave energy into electronic circuits. The principles that govern the operation of conventional radio-frequency antennas can be extended to much higher frequencies and be applied to produce nano-metallic (i.e. plasmonic) antennas that act as "receivers" and "transmitters" for visible light. These traits make them excellent candidates for light trapping in solar cells, light concentration in sub-wavelength photodetectors, or even localized heating for cancer therapies. The unique optical properties of metals at visible frequencies make it difficult to apply traditional antenna design rules. Using full-field electromagnetic simulations and analytical antenna models, we developed new design rules for producing optical antennas with a desired set of optical properties. We then applied these design rules to create antennas that resonantly enhance absorption on thin silicon detectors as well as enhance emission of cathodoluminescence (CL). Through spatial and spectral mapping of both photocurrent and CL we clearly show the fundamental and higher-order resonant modes of these antennas. With CL we are also able to map the spatial distribution of these resonant modes with nanometer resolution. In addition to these specific demonstrated applications, the results of this work enable optical engineers to more easily design a myriad of plasmonic devices that employ optical antenna structures, including nanoscale photodetectors, light sources, sensors, and modulators.
Download or read book Optical Antennas written by Mario Agio and published by Cambridge University Press. This book was released on 2013-01-03 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: This consistent and systematic review of recent advances in optical antenna theory and practice brings together leading experts in the fields of electrical engineering, nano-optics and nano-photonics, physical chemistry and nanofabrication. Fundamental concepts and functionalities relevant to optical antennas are explained, together with key principles for optical antenna modelling, design and characterisation. Recognising the tremendous potential of this technology, practical applications are also outlined. Presenting a clear translation of the concepts of radio antenna design, near-field optics and field-enhanced spectroscopy into optical antennas, this interdisciplinary book is an indispensable resource for researchers and graduate students in engineering, optics and photonics, physics and chemistry.
Download or read book Optical Antennas written by Mario Agio and published by . This book was released on 2012 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt: A consistent and systematic review of recent advances in optical antenna theory and practice, written by leading experts.
Download or read book Optical Antennas written by Aluc Andrea Agio Mario and published by . This book was released on 2013 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt: This consistent and systematic review of recent advances in optical antenna theory and practice brings together leading experts in the fields of electrical engineering, nano-optics and nano-photonics, physical chemistry and nanofabrication. Fundamental concepts and functionalities relevant to optical antennas are explained, together with key principles for optical antenna modelling, design and characterisation. Recognising the tremendous potential of this technology, practical applications are also outlined. Presenting a clear translation of the concepts of radio antenna design, near-field optics and field-enhanced spectroscopy into optical antennas, this interdisciplinary book is an indispensable resource for researchers and graduate students in engineering, optics and photonics, physics and chemistry.
Download or read book Surface Plasmon Nanophotonics written by Mark L. Brongersma and published by Springer. This book was released on 2007-09-18 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses a new class of photonic devices, known as surface plasmon nanophotonic structures. The book highlights several exciting new discoveries, while providing a clear discussion of the underlying physics, the nanofabrication issues, and the materials considerations involved in designing plasmonic devices with new functionality. Chapters written by the leaders in the field of plasmonics provide a solid background to each topic.
Download or read book Tip Enhancement written by and published by Elsevier. This book was released on 2011-09-22 with total page 339 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses the recent advances in the area of near-field Raman scattering, mainly focusing on tip-enhanced and surface-enhanced Raman scattering. Some of the key features covered here are the optical structuring and manipulations, single molecule sensitivity, analysis of single-walled carbon nanotubes, and analytic applications in chemistry, biology and material sciences. This book also discusses the plasmonic materials for better enhancement, and optical antennas. Further, near-field microscopy based on second harmonic generation is also discussed. Chapters have been written by some of the leading scientists in this field, who present some of their recent work in this field.·Near-field Raman scattering·Tip-enhanced Raman spectroscopy·Surface-enhanced Raman spectroscopy·Nano-photonics·Nanoanalysis of Physical, chemical and biological materials beyond the diffraction limits·Single molecule detection
Download or read book Surface Plasmons on Smooth and Rough Surfaces and on Gratings written by Heinz Raether and published by Springer. This book was released on 2006-04-11 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book reviews the properties of surface plasmons that depict electromagnetic surface waves or surface plasma polaritons. Their propagation on smooth and corrugated surfaces (with rough or grating profiles) is considered. In the latter case, the corrugations can cause strong coupling of the surface plasmons with photons leading to resonances with a strong enhancement of the electromagnetic field in the surface. Coupling and field enhancement are the most prominent phenomena on corrugated surfaces and lead to numerous important applications. Attention has been focused on the explanation of the physics. To keep the text readable, sophisticated calculations have been avoided, and instead various applications dealing with enhanced light emission, nonlinear optics, SERS, and other cases of interest are discussed.
Download or read book Plasmonic Optics written by Yongqian Li and published by . This book was released on 2017-02 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spontaneous Emission Rate Enhancement Using Optical Antennas written by Nikhil Kumar and published by . This book was released on 2013 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spontaneous Emission Rate Enhancement Using Optical Antennas by Nikhil Kumar Doctor of Philosophy in Engineering - Electrical Engineering and Computer Sciences University of California, Berkeley Professor Eli Yablonovitch, Chair The miniaturization of electronics has relentlessly followed Moore's law for the past several decades, allowing greater computational power and interconnectivity than ever before. However, limitations on power consumption on chip have put practical limits on speed. This dissertation describes the role that optical antennas can play in reducing power consumption and increasing efficiency and speed for on-chip optical interconnects. High speed optical communication has been dependent on the laser for its narrow linewidth and high modulation bandwidth. It has long outperformed the LED for both practical reasons and very suitable physical characteristics. Lasers however have some downsides when considering short distance communications which may not require narrow linewidths. Typically, they require high powers, take up more space and the rate is inherently limited by gain saturation. Light Emitting Diodes (LEDs) on the other hand are limited by spontaneous emission, a rate that is dependent upon its electromagnetic environment. The use of metallic optical nano-antennas can significantly increase a light emitters coupling to its environment and potentially achieve a rate orders of magnitude faster than stimulated emission. Coupling a light emitter into an efficient nano-optical antenna serves three purposes - 1) a much faster modulation speed can be achieved due to a faster rate of spontaneous emission, 2) the footprint of such a device would be shrunk to the nano-scale, ultimately necessary for large scale integration and 3) the overall efficiency of the emitter can be increased. While the main motivation behind this work is for short distance communications, optical antennas can serve in a host of applications including photodetectors, solar cells, nano-imaging, bio-sensing and data storage. In this thesis we derive the theory behind optical antennas and experimentally show an enhanced spontaneous emission rate.
Download or read book Optical Antenna Enhanced Spontaneous Emission in Semiconductors written by Kevin James Messer and published by . This book was released on 2016 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical antennas can be used to dramatically increase the rate that semiconductors spontaneously emit photons. While traditional LEDs are limited in bandwidth due to the "slow" rate of spontaneous emission, antenna-enhanced LEDs have the potential to be a fast, efficient, nanoscale light emitter. Traditionally, lasers have dominated LEDs as the emitter in optical interconnects due to a 200x speed advantage of stimulated emission over spontaneous emission. This paradigm may be reversed by coupling LEDs to optical antennas. In fact, antenna enhanced spontaneous emission can be faster than the fastest stimulated emission. Spontaneous emission originates from dipole fluctuations within the emitting material. The size of these fluctuations is much less than the wavelength of light emission, which leads to slow spontaneous emission. Coupling the material to an optical antenna corrects the size mismatch and improves the rate of radiation. An optical antenna circuit model is developed to predict the degree to which spontaneous emission can be enhanced. The circuit model presented in this dissertation shows that enhancement over 1000x is possible while still maintaining greater than 50% efficiency. The circuit model provides insight how to design optical antennas for coupling to dipole sources, for maximum enhancement, and for high efficiency. A method for incorporating the anomalous skin effect, often overlooked in metal optics, is provided. While FDTD/FEM simulations cannot include this effect due to its nonlocal nature, its impact can be examined through the use of the optical antenna circuit model. Analysis of the tradeoff between achieving large spontaneous emission enhancement and maintaining high efficiency leads to an ideal antenna feedgap size of 10nm. Experimental demonstration of spontaneous emission enhancement from InP coupled to an arch-dipole antenna is presented. Photoluminescence measurements show light emission from antenna-coupled InP over bare InP ridges was enhanced by 120x. The results correspond to a 14x enhancement of spontaneous emission once absorption enhancement is taken into account. To improve on the previous results, 2D materials from the family of transition metal dichalcogenides are used as the active material. In monolayer form, these materials are direct band gap semiconductors with very low rates of surface recombination. The cavity-backed slot antenna is used to couple to the monolayer semiconductor. The resonant properties of the cavity-backed slot antenna are measured through dark-field scattering and used to match the antenna resonance to the wavelength of light emission. A WSe2 monolayer is etched into ribbons and coupled to the hotspot of a silver cavity-backed slot antenna resulting in an observed spontaneous emission enhancement of 318x. Finally, an unetched MoS2 monolayer is coupled to an array of gold cavity-backed slot antennas in order to demonstrate both high enhancement and high quantum efficiency. Spatially resolved photoluminescence measurements show efficient emission only in the location of optical antennas. Areas of the MoS2 monolayer coupled to antennas show 7% quantum efficiency corresponding to a >250x increase in efficiency over bare MoS2 monolayers. These results demonstrate the exciting potential for antenna-enhanced LEDs to be both fast and efficient light emitters.
Download or read book Cylindrical Antennas and Arrays written by Ronold W. P. King and published by Cambridge University Press. This book was released on 2002-10-10 with total page 650 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explains how to design, analyse and test cylindrical antenna arrays from a practical engineering standpoint. Written by three of the leading engineers in the field, this book is destined to become established as the basic reference in the field for many years to come.
Download or read book Optical Vector Near field Imaging for the Design of Impedance Matched Optical Antennas and Devices written by Robert L. Olmon and published by . This book was released on 2012 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: Antennas control and confine electromagnetic energy, transforming free-space propagating modes to localized regions. This is not only true for the traditional classical radio antenna, but also for structures that interact resonantly at frequencies throughout the visible regime, that are on the micro- and nanometer size scales. The investigation of these optical antennas has increased dramatically in recent years. They promise to bring the transformative capabilities of radio antennas to the nanoscale in fields such as plasmonics, photonics, spectroscopy, and microscopy. However, designing optical antennas with desired properties is not straightforward due to different material properties and geometric considerations in the optical regime compared to the RF. New antenna characterization tools and techniques must be developed for the optical frequency range. Here, the optical analogue of the vector network analyzer, based on a scattering-type scanning near-field optical microscope, is described and demonstrated for the investigation of the electric and magnetic properties of optical antennas through their electromagnetic vector near-field. Specifically, bringing this microwave frequency tool to the optical regime enables the study of antenna resonant length scaling, optical frequency electromagnetic parameters including current density and impedance, optical antenna coupling to waveguides and nanoloads, local electric field enhancement, and electromagnetic duality of complementary optical antenna geometries.
Download or read book Circular Dichroism and Linear Dichroism written by Alison Rodger and published by Oxford University Press, USA. This book was released on 1997 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an introduction to all those who wish to use the complementary spectroscopic techniques of optical activity (circular dichroism, CD) and optical anisotropy (linear dichroism, LD) for the study of the structure of molecules and interactions between molecules in solution. It emphasizes these techniques and how to use them for both low and high molecular weight molecules. The book begins by describing the principles behind CD and LD and how these techniques can be used in the laboratory without using advanced maths or quantum mechanics. The next chapters describe how both techniques may be applied to the study of biological macromolecules and give a detailed description of how they may be used on small molecules to investigate molecular and electronic structure. The final part contains theoretical derivations of all the equations required for the applications described previously. Specific molecular examples are used to illustrate concepts and to show the reader how to use the techniques in chemical and biological systems. Circular Dichroism and Linear Dichroism is an easy guide to what a prospective user of CD needs to know and explains how LD is not merely an exotic technique only to be practiced by experienced spectroscopists, but may be routinely and usefully employed as an aid to molecular structure determination.
Download or read book Optical Antennas written by Matthias Dominik Wissert and published by KIT Scientific Publishing. This book was released on 2014-09-03 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: The linear and nonlinear resonance behaviour of optical antennas (metallic nanostructures showing resonance behaviour at optical frequencies) made of gold and aluminum using electron-beam lithography is investigated. Specifically, it is of interest how the emission behaviour is changed by the coupling of two antenna arms via a small gap. Experimental techniques applied include dark-field spectroscopy and two-photon luminescence.
