Photonic- Phononic- and Meta-Material Group Activities TETY Photonic- Phononic- and Meta-Material Group Activities Mainly theory, also experiment (characterization) Main research topics Metamaterials Photonic crystals Plasmonic structures Web: http://esperia.iesl.forth.gr/~ppm

Main group members Senior C. M. Soukoulis (TETY & FORTH) M. Kafesaki (FORTH & TETY) E. N. Economou (FORTH) N. Katsarakis (TEI & FORTH) Th. Koschny (FORTH &ISU) PhD T. Gundogdu (exp) Post-docs G. Kenanakis R. S. Penciu A. Reyes-Coronado S. Foteinopoulou Students N. Vasilantonakis Ch. Mavidis I. Tsiapa Web: http://esperia.iesl.forth.gr/~ppm

Main group members Senior C. M. Soukoulis (TETY/FORTH) M. Kafesaki (FORTH/TETY) E. N. Economou (FORTH) N. Katsarakis (TEI/FORTH) Th. Koschny (FORTH/ISU) PhD T. Gundogdu (exp) Post-docs G. Kenanakis (exp) N. H. Shen R. S. Penciu A. Reyes-Coronado S. Foteinopoulou Students N. Vasilantonakis (exp) Ch. Mavidis I. Tsiapa (exp)

Main collaborations FORTH-IESL TETY FORTH-IESL G. Konstantinidis’ group - microfabrication M. Farsari’s group - direct laser writing S. Tzortzakis’ group - THz time domain spectroscopy M. Wegener’s group @ Karlsruhe Institute of Technology, Germany E. Ozbay’s group @ Bilkent University, Turkey J. Pendry’s group @ Imperial College, UK V. Orera group @ Univ. of Zaragoza, Spain Profactor company, Austria ….

Publications (2006-2010) TETY Publications number (with TETY affiliation): ~70 (3 Science, 4 PRL, 4 OL, 26 PRB, 7 APL, 11 OE) Citation number for these publications: ~2000

Current EU Projects TETY Acronym Name Type PHOME PHOtonic MEtamaterials FP7-ICT-FET ENSEMBLE ENgineered SElf-Organized Multi-component structures with novel controllaBLe Electromagnetic Functionalities FP7 NMP NIM_NIL Large Area Fabrication of 3D Negative Index Materials by NanoImprint Lithography ECONAM Electromagnetic Characterization Of NAnostructured Materials Coordination Action FP7 COST Action MP0702, "Towards Functional Sub-wavelength Photonic Structures" COST Action MP0803, "Plasmonic Components and Devices"

Projects (last 6 years) TETY Acronym Name Type PHOME PHOtonic MEtamaterials FP7-ICT-FET ENSEMBLE ENgineered SElf-Organized Multi-component structures with novel controllaBLe Electromagnetic Functionalities FP7 NMP NIM_NIL Large Area Fabrication of 3D Negative Index Materials by NanoImprint Lithography ECONAM Electromagnetic Characterization Of NAnostructured Materials Coordination Action FP7 FENIM Frequency Extension of the Negative Index Materials US Air Force Metamorphose METAMaterials ORganised for radio, millimeter wave and PHOtonic Superlattice Engineering FP6 - Network of Excellence (NoE) PHOREMOST PHOtonics to REalize MOlecular Scale Technologies FP6-NoE DALHM Development and Analysis of Left Handed Materials FP5-IST-FET COST Action MP0702, "Towards Functional Sub-wavelength Photonic Structures" COST Action MP0803, "Plasmonic Components and Devices"

Metamaterials TETY Artificial, structured (in sub-wavelength scale) materials Electromagnetic (EM) properties derive from shape and distribution of constituent units (usually metallic & dielectric components) EM properties not-encountered in natural materials Electrical permittivity Magnetic permeability EM properties Possibility to engineer electromagnetic properties

Left-handed metamaterials TETY Negative electrical permittivity () Negative magnetic permeability () Sov. Phys. Usp. 10, 509 (1968) Negative ε, μ, n Novel and unique propagation characteristics in those materials!

Novel phenomena in left-handed metamaterials TETY Backwards propagation (opposite phase & energy velocity) S=E×H S

Backwards propagation in left-handed metamaterials TETY Backwards propagation in left-handed metamaterials Left-handed slab Source

Novel phenomena in left-handed metamaterials TETY Backwards propagation (opposite phase & energy velocity) S=E×H S Negative refraction AIR LHM, n2<0 θ2 source θ1 LHM air Flat lenses - “Perfect” lenses (subwavelength resolution) Zero-reflection possibility Opposite Doppler effect Opposite Cherenkov radiation …… Interesting physical system New possibilities for light manipulation  important potential applications

Application areas of left-handed metamaterials TETY New solutions and possibilities in Imaging/microscopy Lithography Data storage Communications and information processing (subwavelength guides, optimized/miniaturized antennas & filters, improved transmission lines ...) …. Exploiting the subwavelength resolution capabilities of LHMs

Metamaterials beyond negative index High index metamaterials TETY High index metamaterials Shrinkage of devices Cloaking Low index metamaterials Parallel beam formation Indefinite media Hyperlensing Single-negative media Bi-anisotropic media

Designing left-handed metamaterials TETY Most common approach: Merging structures of negative permittivity (ε) with structures of negative permeability (μ) Split Ring Resonator (SRR), Pendry, 1999 Short-slabs-pair, Shalaev, 2002 j Negative permeability: Structures of resonant loop-currents C L Negative permittivity: Continuous wires E

Microwave (mm-scale) structures TETY

Micro and nano-scale structures TETY Fabricated in MRG 780 nm 1.4 μm

Main investigation aims/directions TETY Analyze, understand, optimize and tailor metamaterial response Achieve optical metamaterials – reduce losses in metamaterials Achieve three-dimensional isotropic left-handed metamaterials Create switchable and tunable metamaterials Devise/analyze new designs and approaches for negative refraction and other interesting effects (chiral, anisotropic, polaritonic metamaterials) Explore novel phenomena and possibilities in metamaterials

Main investigation aims/directions TETY Analyze, understand, optimize and tailor metamaterial response Achieve optical metamaterials – reduce losses in metamaterials Achieve three-dimensional isotropic left-handed metamaterials Create switchable and tunable metamaterials Devise/analyze new designs and approaches for negative refraction and other interesting effects (chiral, anisotropic, polaritonic metamaterials) Explore novel phenomena and possibilities in metamaterials

THz and optical structures Optical metamaterials THz and optical structures TETY 5m Five layers ! Fabricated in Crete Silver in polyimide Optics Letters 30, 1348 (2005) μ<0 @ ~6 THz n<0 @ 1.4 μm Re(n)=-0.6 @ 780 nm

“Magnetic” metamaterials response in high frequencies Optical metamaterials TETY “Magnetic” metamaterials response in high frequencies Al metal Glass substrate No negative permeability at arbitrarily high frequencies Results not affected by metal losses Reducing a a: u.c. size Saturation of response frequency in small length scales (a<500 nm) Vanishing of negative permeability band-width Weakening of permeability resonance

Magnetic permeability by scaling down the structures Optical metamaterials a Reducing size Weakening of magnetic resonance (no negative μ) at small scales

Explaining the observed response TETY Consideration of metal dispersive response in the conductivity: Zhou et. al., 2005 Tretyakov, 2007 Solymar, 1976 Shvets et. al., 2005 For uniform scaling: a: lattice constant Inductive term (electrons inductance) due to electrons inertia (“Difficulty” to accelerate finite mass particles with such high rates) ωp= metal plasma frequency γm=metal collision frequency l S

Explaining the observed response Optical metamaterials Explaining the observed response TETY Consideration of electrons’ kinetic energy, Ee besides magnetic energy, EM (Ee becomes comparable to EM in small scales) Ee can be considered through an equivalent inductance, Le For uniform scaling: a: lattice constant V: wire effective volume ve: electrons velocity ne: e- number density Zhou et. al., PRL, 2005 Penciu et al, PRB, 2010

Optical metamaterials with gain TETY Gain atoms (4-level) embedded in host medium: In Finite Difference Time Domain Method are driven oscillators which couple to the local E field pump Lasing ωa Rate equations: Driven oscillators: Same method for examining lasing threshold in photonic crystals (with M. Farsari) Maxwell’s equations: σa is the coupling strength of P to the external E field and ΔN=N2-N1 C. Soukoulis’ collaboration with Karlsruhe and MRG Phys. Rev. B: 79, 241104 (Rapid) (2009)

Main investigation aims/directions TETY Analyze, understand, optimize and tailor metamaterial response Achieve optical metamaterials – reduce losses in metamaterials Achieve three-dimensional isotropic left-handed metamaterials Create switchable and tunable metamaterials Devise/analyze new designs and approaches for negative index behaviour (chiral or anisotropic metamaterials) Explore novel phenomena and possibilities in metamaterials

Towards 3D isotropic left-handed materials New designs/approaches Towards 3D isotropic left-handed materials TETY 1D Gold in polyimide Re(n)/Im(n)|n = -1 = 5 Double negative @ ~200 THz (1.5 μm) 2D Double negative @ ~160 THz FORTH & ISU, Opt. Express, 2009

Main investigation aims/directions TETY Analyze, understand, optimize and tailor metamaterial response Achieve optical metamaterials – reduce losses in metamaterials Achieve three-dimensional isotropic left-handed metamaterials Create switchable and tunable metamaterials Devise/analyze new designs and approaches for negative index behaviour (chiral or anisotropic metamaterials) To explore novel phenomena and possibilities in metamaterials

Switchable and tunable metamaterials The principle: TETY The principle: UV PRB, 79, 161102 (R) (2009) Collaboration with S. Tzortzakis’ group Blue-shift tunable metamaterials & Dual-band switches

Blue-shift tunable metamaterials & Dual-band switches TETY Blue-shift tunable metamaterials & Dual-band switches Collaboration with S. Tzortzakis’ group Blue-shift tunable metamaterials & Dual-band switches PRB, 79, 161102 (R) (2009) (c)

Main investigation aims/directions TETY Analyze, understand, optimize and tailor metamaterial response Achieve optical metamaterials – reduce losses in metamaterials Achieve three-dimensional metamaterials Create switchable and tunable metamaterials Devise/analyze new designs and approaches for negative refraction and other interesting effects (chiral, anisotropic, polaritonic metamaterials) Explore novel phenomena and possibilities in metamaterials

Negative refractive index in chiral media New designs/approaches Negative refractive index in chiral media TETY Chiral structure: not-identical to its mirror image Different index for left- and right- handed circularly polarized waves Alternative path to achieve negative index Besides negative index: Polarization rotation Circular dichroism Negative index Large polarization rotation Large circular dichroism

Main investigation aims/directions TETY Analyze, understand, optimize and tailor metamaterial response Achieve optical metamaterials – reduce losses in metamaterials Achieve three-dimensional metamaterials Create switchable and tunable metamaterials Devise/analyze new designs and approaches for negative refraction and other interesting effects (chiral, anisotropic, polaritonic metamaterials) Explore novel phenomena and possibilities in metamaterials

Novel phenomena and possibilities in metamaterials TETY Super-lensing in anisotropic “negative” metamaterials Electromagnetically-induced-transparency in metamaterials Repulsive Casimir force in chiral metamaterials

Novel phenomena and possibilities in metamaterials TETY Super-lensing in anisotropic “negative” metamaterials Electromagnetically-induced-transparency in metamaterials Repulsive Casimir force in chiral metamaterials

Superlensing in anisotropic metamaterials TETY Superlensing in anisotropic metamaterials dSource d dImage z x Sub-wavelength resolution possibility in anisotropic metamaterials z x Perfect lensing conditions: Propagating components: Omnidirectional total transmission Evanescent components: Excitation of dispersionless surface modes Possibility for thin “lenses”! (less influenced by losses)

Negative refraction by an anisotropic left-handed slab TETY Anisotropic “perfect” lens: Negative refraction & focusing Negative refraction by an anisotropic left-handed slab Focusing in an anisotropic left-handed slab

Novel phenomena and possibilities in metamaterials TETY Super-lensing in anisotropic “negative” metamaterials Electromagnetically-induced-transparency (EIT) in metamaterials Repulsive Casimir force in chiral metamaterials

Novel phenomena/possibilities EIT in metamaterials TETY Coupling of a “bright” (coupled to incident field) and a “dark” (not coupled to incident field) resonance leads to strong dispersion & low absorption Demonstration of realistic structures exhibiting EIT effect ( low loss – slow light) Strong coupling Weak coupling

Novel phenomena and possibilities in metamaterials TETY Super-lensing in anisotropic “negative” metamaterials Electromagnetically-induced-transparency in metamaterials Repulsive Casimir force in chiral metamaterials

Repulsive Casimir force in chiral metamaterials Novel phenomena/possibilities Repulsive Casimir force in chiral metamaterials TETY Casimir force: force between two uncharged plates in vacuum Origin of the Casimir Force Vacuum (zero point) energy, E, between plates increases with separation, causing an attracting Casimir force, FC. Dimensional reasoning gives d F Detrimental in MEMs Hendrik Casimir (1909-2000) Strongest force between two neutral objects (d<10nm)

Repulsive Casimir force in chiral metamaterials (2) Novel phenomena/possibilities Repulsive Casimir force in chiral metamaterials (2) TETY Calculating Casimir force General recipe: 1) Obtain classically all EM eigenmodes 2) Calculate the zero point energy of these eigenmodes Vacuum The eignemodes are TM (electric or p-waves, surface plasmons) and TE (magnetic or s-waves) d Chirality of the same sign in materials 1,2  positive contribution to f  reduced attraction and even repulsion!

Repulsive Casimir force in chiral metamaterials (3) Novel phenomena/possibilities Repulsive Casimir force in chiral metamaterials (3) TETY Casimir energy vs separation of chiral slabs repulsive Casimir force zero Casimir force and stable equilibrium E/Ahck3 Phys. Rev. Lett. 103, 103602 (2009). ωk ~ chirality strength k0d Chiral metamaterial slabs with electric, magnetic, and chiral response functions  a repulsive Casimir force for sufficiently strong chirality

Main investigation aims/directions TETY Analyze, understand, optimize and tailor metamaterial response Achieve optical metamaterials – reduce losses in metamaterials Achieve three-dimensional metamaterials Create switchable and tunable metamaterials Devise/analyze new designs and approaches for negative refraction and other interesting effects (chiral, anisotropic, polaritonic metamaterials) Explore novel phenomena and possibilities in metamaterials Photonic crystals Plasmonic systems Besides metamaterials ?

Lasing threshold for 2D inverse photonic crystals (TM) TETY Lasing threshold for 2D inverse photonic crystals (TM) Air Gain Thickness: 8400 nm E k H Lattice constant a = 840 nm Width of square hole: w = 540 nm Emission frequency: 100 THz Dielectric constant of gain: 11.7 Much lower lasing threshold (at upper band edge) than bulk gain

Main investigation aims/directions TETY Analyze, understand, optimize and tailor metamaterial response Achieve optical metamaterials – reduce losses in metamaterials Achieve three-dimensional metamaterials Create switchable and tunable metamaterials Devise/analyze new designs and approaches for negative refraction and other interesting effects (chiral, anisotropic, polaritonic metamaterials) Explore novel phenomena and possibilities in metamaterials Thank you. Photonic crystals Plasmonic systems Besides metamaterials ?