Tutorials in Complex Photonic Media

Excerpt

An increasingly large number of high- and low-tech technologies and devices benefit from employing optics and photonics phenomena, the latter originally being termed photon-based electronics. Progress in the research fields of optics and photonics, which have both experienced continuously strong growth over the last few decades, critically depends on the understanding and utilization of the physical, chemical and structural properties of optical materials. The optical materials used in traditional optics technology were macroscopically homogeneous in that their scale of inhomogeneity was much less than the wavelength. In more recent years, multiple breakthroughs have involved inhomogeneous, composite, and multiphase materials, whose structures are either photoinduced or determined by synthesis or fabrication. Examples include holography, optics of scattering media, and metamaterials. These breakthroughs make photonic materials inherently complex. The broad range of physical phenomena underlying complex photonic media makes it difficult for scientists, engineers, and students entering the field to navigate through the range of topics and to understand clearly how they relate to each other.

The purpose of this book is to provide the necessary coverage and inspire the reader's curiosity about the fascinating subject of complex photonic media. All of the tutorial chapters are designed to start with the basics and gradually move toward discussion of more advanced topics. We thus envisage that students and scholars with diverse backgrounds and levels of expertise will find this text interesting and useful. The book can be used as a supplemental text in courses on nanotechnology or optical materials, or a variety of other courses. It can also be used as the main text in a more focused course aimed at fundamental properties of scattering media and metamaterials. The anticipated level of preparation is equivalent to advanced senior undergraduate level, beginning graduate level, or higher. The book covers the topics in the following (rather loose) categorization:

Negative index materials (NIMs). One of the most exciting developments in complex photonic media in recent years is the realization that the basic parameters describing the electromagnetics of simple, isotropic media can take simultaneously negative values. This leads to all kinds of interesting phenomena, from a revised understanding of Snell's law, to lenses that defeat the conventional diffraction resolution limit. In “Negative Refraction” (Chapter 1), Martin W. McCall and Graeme Dewar describe the basic theory and impetus for negative refraction research. In “Optical Hyperspace: Negative Refractive Index and Subwavelength Imaging” (Chapter 2), Leonid V. Alekseyev, Zubin Jacob, and Evgenii Narimanov explore nonmagnetic routes that exploit materials with hyperbolic dispersion relations.

Magneto-optics. The term magneto-optics is used when the direction and polarization state of light are controlled by the application of external magnetic fields, offering opportunities for optical storage and isolation in optical systems. In “Magneto-optics and the Kerr Effect with Ferromagnetic Materials” (Chapter 3), Allan D. Boardman and Neil King introduce the magneto-optics derived from air-ferroelectric interfaces and glass∕ferromagnetic film∕air multilayer systems. “Nonlinear Magneto-Optics” (Chapter 4) by Yutaka Kawabe gives emphasis to the relationship between the tensors describing the nonlinearity and the underlying crystal point group symmetry. In “Optical Magnetism in Plasmonic Metamaterials” (Chapter 5), Gennady Shvets and Yaroslav A. Urzhumov describe some of the difficult challenges that lie ahead for achieving magnetic activity at optical frequencies.

Chiral media and vortices. Light, being composed of unit spin photons, is inherently chiral. However, chirality in optical systems can also be engaged at structural and macroscopic electromagnetic levels. Structural chirality is covered by Ian Hodgkinson and Levi Bourke in “Chiral Photonic Media” (Chapter 6), which describes the multilayer matrix formalism for novel elliptically polarized filters. When optical beams interfere, phase singularities occur; in “Optical Vortices” (Chapter 7) Kevin O'Holleran, Mark R. Dennis, and Miles J. Padgett describe some of the remarkable topological knots and 3D twists that result.

Scattering in periodic and random media. Scattering of light is fundamental to complex photonic media. Structures that are periodic are generally referred to as photonic crystals. In “Photonic Crystals: From Fundamentals to Functional Photonic Materials” (Chapter 8), Durga P. Aryal, Kosmas L. Tsakmakidis, and Ortwin Hess describe how photonic bandstructure emerges in both 1- and 2D structures, and how optical switching is achievable in inverse-opal structures. When the material inhomogeneity is random, different methods must be employed. In “Wave Interference and Modes in Random Media” (Chapter 9), Azriel Z. Genack and Sheng Zhang describe photon transport in a medium in terms of the interference of multiply scattered partial waves as well as by considering the different spatial, spectral, and temporal characters of the electromagnetic modes.

Photonic media with gain and lasing phenomena. Photonic media with gain and lasing phenomena represents the generic class of active photonic media. “Chaotic Behavior of Random Lasers” (Chapter 10) by Diederik Wiersma, Sushil Mujumdar, Stefano Cavalieri, Renato Torre, Gian-Luca Oppo, and Stefano Lepri examines the irreproducibility of experimental emission spectra and the change of statistics at near threshold. “Lasing in Random Media” (Chapter 11) by Hui Cao provides a detailed review of the concepts and advances in the field of random lasers. “Feedback in Random Lasers” (Chapter 12) by Mikhail A. Noginov emphasizes the significance of the strength of scattering andࢧor feedback in determining the properties of random lasers. In “Optical Metamaterials with Zero Loss and Plasmonic Nanolasers” (Chapter 13), Andrey Sarychev discusses how nano-horseshoe inclusion in an active host medium results in a plasmonic nanolaser.

Fundamentals. In “Resonance Energy Transfer: Theoretical Foundations and Developing Applications” (Chapter 14), David L. Andrews explores how the intricate interplay between quantum mechanical and electromagnetic medium properties leads to schemes for energy transfer and all-optical switching. In “Optics of Nanostructured Materials from First Principle Theories” (Chapter 15) Vladimir I. Gavrilenko provides a tutorial on the microscopic modelling of optical response functions using density functional theory and related approaches.

Organic photonic materials. Materials whose nonlinear coefficients often exceed their inorganic counterparts both in magnitude and response rate are examined in “Organic Photonic Materials” (Chapter 16) by Larry R. Dalton, Philip A. Sullivan, Denise H. Bale, Scott R. Hammond, Benjamin C. Olbricht, Harrison Rommel, Bruce Eichinger, and Bruce H. Robinson. These authors explore organic optical material design in terms of critical structure∕function relationships. “Charge Transport and Optical Effects in Disordered Organic Semiconductors” (Chapter 17) by Harry H. L. Kwok, You-Lin Wu, and Tai-Ping Sun highlights how, as with regular semiconductors, charge transport can be modified by doping in organic materials, which possess enhanced carrier mobilities.

Holographic media. “Holography and Its Applications” (Chapter 18) by H. John Caulfield and Chandra S. Vikram discusses holograms used as parts of complex light-controlled or light-defined systems that manipulate the direction, spectrum, polarization, or speed of pulse propagation of light in a medium.

Slow and fast light. Slow and fast light is an intriguing topic demystified by Joseph E. Vornehm, Jr. and Robert W. Boyd in the final chapter “Slow and Fast Light” (Chapter 19). The authors show how manipulation of the material dispersion can lead to very slow, halted, or even backward propagating optical pulses.

The conception of Tutorials in Complex Photonic Media lies in an effort to consolidate the conference series, Complex Mediums: Light and Complexity, a subconference of the annual SPIE Optics and Photonics meeting held over the years 2003–2006. Incentive for this book was also largely compelled by Introduction to Complex Mediums for Optics and Electromagnetics, edited by Werner S. Weiglhofer and Akhlesh Lakhtakia, SPIE Press (2003), which is a consolidation of the Complex Mediums conferences from 1999 to 2002. We have taken special emphasis in this book to avoid the somewhat disjointed presentation that often accompanies books based on conferences. To this end, all of the chapters underwent round-robin reviews by several editors and coauthors who were frequently not directly involved in the research area. Much “back and forth” has hopefully ironed out the specialist's tendency to dive headlong into details that can only be appreciated once sufficient underpinning motivational material has been presented. Another issue is notation. Eventually, we decided that keeping a consistent notation throughout the book would be self-defeating, as anyone entering a new area must, to a certain extent, be flexible to individual authors' preferences. Nevertheless, we went to some lengths to ensure that the notation within each chapter is consistent.

The four editors who undertook this project have had a unique opportunity to work with some of the leading specialists in the field. Of course, there have been frustrations, but in the end, we hope that that this book presents a broad and balanced summary that will lead many others to take up the exciting challenges of working in complex photonic media. In the introduction to the predecessor volume noted above, Akhlesh Lakhtakia wrote ‘I shall be delighted if a companion volume were published after another two or three editions of this conference.’ Well, here it is.

Mikhail A. Noginov

Graeme Dewar

Martin W. McCall

Nikolay I. Zheludev

September 2009