Optical properties and the realization possibilities of nanostructured metamaterials (Crete, 2009) Print

 

This edition of the Metamaterials School was devoted to the optical properties and the realization possibilities of nanostructured metamaterials, targeting operation in the near IR and optical regime. The recent and foreseen developments in terms of fabrication, optical characterization, and novel optical phenomena related with nanostructured metamaterials were reviewed and analyzed by experts of the field. See details here.

Recorded lectures (video and slides) of the school can be also found here.

  

Abstracts of lectures and some related files.

 (To open some of the videos properly it is necessary to install a special video codec from this website: http://download.techsmith.com/tscc/tscc.exe (it is a small and very easy to install file)).

  

Part 1:  Current research and recent developments on optical metamaterials

 

•Â Â Â  Photonic metamaterials: Progress and challenges - V. Shalaev 

 Part 1 - AVI file (voice is lost in the last part of this file),   Part 1 - pdf file, Part 2 - AVI file,   Part 2 - pdf file .
We review recent progress in developing metamaterials for the optical part of the spectrum as well as the new emerging field of transformation optics. A new paradigm of engineering space for light with transformation optics and its applications for cloaking and "super-imaging" will be also discussed.
This introductory overview lecture was targeted to a wide audience of specialists in nanoscience and material science, especially for those studying nanostructured materials with engineered electromagnetic properties and their applications to cloaking.

Part 2: Nanofabrication
 

  •Â Â Â  Introductory overview of various fabrication technologies – A. Boltasseva

AVI file,  pdf file

Different approaches for optical metamaterial fabrication will be discussed. The advantages, drawbacks and challenges of different fabrication techniques including electron-beam lithography (EBL), focused-ion beam (FIB) milling, interference lithography (IL) and nanoimprint lithography (NIL) and direct laser writing will be outlined. Since the possibility of creating a truly three-dimensional (3D) metamaterial is critical for real-life applications and the future of this research area, the recent developments on large-scale, multiple-functional-layer metamaterials will be discussed, and alternative methods for 3D fabrication of complex structures will be mentioned. Throughout the lecture, main breakthroughs in fabrication of optical metamaterials will be described, as well as challenges facing future manufacturing of optical metamaterials.
This introductory overview lecture was targeted to a wide audience of specialists in nanoscience and material science, especially for those studying advanced nanofabrication techniques.

•Â Â Â  Self-organization approach to metamaterials – D. Pawlak

AVI file, pdf file

Until now, metamaterials are mostly made as periodic structures by sophisticated techniques, resulting in different restrictions. One possible way to move beyond this approach, would be using the self-organization mechanism and chemical methods. Self-organization is already established in the formation of photonic crystals (opals). This bottom-up approach could be a good alternative to mainstream metamaterial manufacturing techniques, and furthermore could result in a cheaper way of materials manufacturing, different functionalities of the materials and for realizing different new applications. The examples of various self-organization approaches towards metamaterials will be discussed, and some potential techniques will be described.

•Â Â Â  Advanced nanoimprint lithography for 3D photonic structures - Clivia Sotomayor

AVI file, pdf file
This lecture was targeted to specialists in nanoscience and material science, especially for those studying advanced nanofabrication techniques.


Part 3: Terahertz metamaterials:

 • Fabrication, characterization and applications - Willie Padilla


AVI file, pdf file

This lecture was targeted to specialists in nanoscience and material science, especially for those studying advanced nanofabrication techniques and characterization of nanostructrured materials in the terahertz frequency range.


Part 4: Effective medium descriptions of metamaterials

•Â Â Â  Definitions, limitations, chirality and bi-anisotropy – S. Tretyakov

AVI file does not exist, pdf file, hand-written notes 1, hand-written notes 2


In this introductory lecture we will discuss the definitions and physical meaning of effective materials parameters, such as permittivity and permeability. Also, effective parameters of chiral and more general bi-anisotropic media will be introduced and discussed. We will explain the notions of frequency and spatial dispersion and explain how media with enough weak spatial dispersion can be modelled by effective medium parameters, including artificial magnetism and chirality. The validity region for effective medium description as well as fundamental limitations on the values of the effective parameters will be considered.
This introductory overview lecture was targeted to a wide audience of specialists in nanoscience and material science, especially for students in electromagnetics of complex materials, who study electromagnetic properties of micro- and nanostructured materials with engineered electromagnetic properties.

•Â Â Â  Effective medium modelling of plasmonic metamaterials - G. Shvets

AVI file, pdf file
Plasmonic metamaterials present an unprecedented opportunity for engineering their electromagnetic properties and developing novel devices. For example, one can develop negative index materials, NIMs) at optical frequencies possessing both negative effective dielectric permittivity and magnetic permeability at optical frequencies. I will describe how the effective parameters of such plasmonic etamaterials can be extracted. We will start with examining electrostatic resonances of periodic plasmonic lattices and then move on to developing a perturbation theory accounting for the finite optical frequency. I will also draw comparisons between magnetic responses of simple microwave and plasmonic elements (such as split rings etc.) and illustrate why the optical magnetism is difficult to achieve. Finally, I will describe the effects of spatial dispersion in metallic metamaterials using simple examples such as wire meshes.
This lecture was targeted to a specialists in nanoscience and material science, especially for those studying electromagnetic properties of micro- and nanostructured materials with engineered optical properties. The main goal of the lecture is to discuss approaches to effective material parameter modelling of complex nanostructured materials.

•Â Â Â  Dynamic analytical modelling of metamaterials - C. Simovski

AVI file does not exist, pdf file
The generalization of local material parameters conventionally introduced for quasi-static lattices to the dynamic case of the wave propagation in the lattice (when the ratio lattice period/wavelength of the fundamental Bloch harmonic attains 0.1-0.4) is discussed. Material parameters for lattices of small resonant scatterers are extracted from dispersion characteristics of a lattice treated as a set of grids of electric and magnetic dipoles. The comparison with other possible sets of material parameters of such lattices is presented. The extraction of local material parameters of a lattice from plane-wave scattering coefficients of a layer containing several unit cells across it is discussed. The comparison with the known Nicolson-Ross-Weir method of electromagnetic characterization of continuous layers is done taking into account the Drude transition effect. This lecture was targeted to specialists in nanoscience and material science, especially for those studying electromagnetic properties of micro- and nanostructured materials with engineered electromagnetic properties.

•Â Â Â  Optics of active metamaterials - A. Sarychev

AVI file, pdf file
Light is in a sense “one-handed” when interacting with atoms of conventional materials. This is because out of the two field components of light, electric and magnetic, only the electric “hand” efficiently probes the atoms of a material, whereas the magnetic component remains relatively unused because the interaction of atoms with the magnetic field component of light is normally weak. Metamaterials, i.e. artificial materials with rationally designed properties, can enable the coupling of both of the field components of light to meta-atoms, enabling entirely new optical properties and exciting applications with such “two-handed” light. For example, specifically shaped metal nanoantennas can exhibit strong magnetic properties in the optical spectral range due to excitation of the magnetic plasmon resonance. A case in which a metamaterial comprising such meta-atoms can demonstrate both left handiness and negative permeability in the optical range is discussed. We show that high losses predicted for optical left-handed materials can be compensated in the gain medium. Gain allows achieving local generation in magnetically active metamaterials. The possibility for the metamaterial to exhibit optical ferromagnetism is discussed. We propose a plasmonic nanolaser, where the metal nanoantenna operates in a fashion similar to a resonator. The size of the proposed plasmonic laser is much smaller than the light wavelength. Therefore, it can serve as a very compact source of coherent electromagnetic radiation and can be incorporated in future plasmonic devices. We consider various collective phenomena like superradiance in an array of nanolasers when phases of all nanolasers are synchronized and they radiate as one superlarge atom.
This lecture was targeted to specialists in nanoscience and material science, especially for those studying electromagnetic properties of active nanostructured materials with engineered optical properties.

Part 5: Measurements of optical properties of metamaterials

•Â Â Â  Experimental characterization techniques for nanostructured metamaterials – H. Giessen


This lecture was targeted to specialists in nanoscience and material science, especially for those studying electromagnetic properties of nanostructured materials with engineered optical properties and developing approaches to their electromagnetic characterization.

•Â Â Â  Measurements of optical properties of nanostructured metamaterials – N. Feth 

Part 1- AVI file, Part 1 - pdf file, Part 2 - pdf file (for Part 2, video does not exist).
We review recent experimental work on photonic metamaterials that offer unique possibilities regarding magnetism at elevated frequencies, negative refractive indices and optical nonlinearities. Here, we focus on the characterization techniques of metamaterials as well as of single isolated photonic atoms - the fundamental building blocks of metamaterials. Linear characterization methods give linear transmittance and reflectance spectra. In order to obtain reliable information about the refractive index, we need to measure the phase delay that can be determined via time-of-flight measurements. In non-linear optical experiments, we gain insight into the non-linear optical properties of photonic metamaterials like second- and third-harmonic generation. Besides the characterization of metamaterial arrays, we also investigate the linear-optical properties of isolated photonic atoms by means of an advanced modulation technique. With this technique we also investigate the coupling mechanisms between single photonic atoms and its dependence on distance and relative orientation. Plasmon resonances are the origin of the unique properties of metamaterials. These can be mapped with nanometer-resolution using electron energy loss spectroscopy (EELS). We apply EELS for mapping the fundamental plasmon resonance of split-ring resonators (SRR) that generates the magnetic dipole moment of SRR.
 

Recorded lectures (video and slides) of the school can be found also here.

The school was organized in conjunction with the ETOPIM conference (its web site is here).