Photonic- Phononic- and Meta-Material Group Activities

Web: http://esperia.iesl.forth.gr/~ppm

TETYTETY

Main research topicsMetamaterials

Photonic crystalsPlasmonic structures

Mainly theory, also experiment (characterization)

SeniorC. M. Soukoulis (TETY/FORTH)M. Kafesaki (FORTH/TETY)

E. N. Economou (FORTH)N. Katsarakis (TEI/FORTH)Th. Koschny (FORTH/ISU)

Post-docsG. Kenanakis (exp)

N. H. Shen

R. S. Penciu

A. Reyes-Coronado

S. Foteinopoulou

PhDT. Gundogdu (exp)

StudentsN. Vasilantonakis (exp)Ch. MavidisI. Tsiapa (exp)

Main group members TETYTETY

M. Wegener’s group @ Karlsruhe Institute of Technology, Germany

E. Ozbay’s group @ Bilkent University, Turkey

FORTH-IESLG. Konstantinidis’ group - microfabricationM. Farsari’s group - direct laser writing S. Tzortzakis’ group - THz time domain spectroscopy

V. Orera group @ Univ. of Zaragoza, Spain

Main collaborations TETYTETY

Profactor company, Austria….

J. Pendry’s group @ Imperial College, UK

Publications number (with TETY affiliation): ~70

Citation number for these publications: ~2000

(3 Science, 4 PRL, 4 OL, 26 PRB, 7 APL, 11 OE)

Publications (2006-2010) TETYTETY

Artificial, structured (in sub-wavelength scale) materials

Electromagnetic (EM) properties Electromagnetic (EM) properties derive from derive from shapeshape and and distributiondistribution

of constituent units (usually of constituent units (usually metallic & dielectric components)metallic & dielectric components)

EM properties not-encountered in EM properties not-encountered in natural materialsnatural materials

Electrical Electrical permittivitypermittivity

Magnetic Magnetic permeabilitypermeability

EM properties

Possibility to engineer electromagnetic properties

MetamaterialsTETYTETY

Sov. Phys. Usp. 10, 509 (1968)

2n n

realkc

Negative Negative εε, , μμ, n, n Novel and unique propagation Novel and unique propagation characteristics in those materials!characteristics in those materials!

Negative electrical permittivity () Negative magnetic permeability ()

Left-handed metamaterials

TETYTETY

• Zero-reflection possibility • Opposite Doppler effect • Opposite Cherenkov

radiation• ……

LHMair air

Flat lenses - “Perfect” lenses (subwavelength resolution)

•Interesting physical system

•New possibilities for light manipulation important potential applications

Negative refraction

AIR LHM, n2<0

θ2

source

θ1

Backwards propagation (opposite phase & energy velocity)

S=E×H

S

Novel phenomena in left-handed metamaterials TETYTETY

•Imaging/microscopy

•Lithography

•Data storage

•Communications and information processing (subwavelength guides, optimized/miniaturized antennas & filters, improved transmission lines ...)

•….

New solutions and possibilities in

Exploiting the subwavelength resolution

capabilities of LHMs

Application areas of left-handed metamaterials TETYTETY

Low index metamaterials

Indefinite media

High index metamaterials Shrinkage of devices

Cloaking

Bi-anisotropic mediaSingle-negative media

Hyperlensing

Parallel beam formation

Metamaterials beyond negative index TETYTETY

Most common approach: Merging structures of negative permittivity (ε) with structures of negative permeability (μ)

Negative permeability: Structures of resonant loop-currents

E

Negative permittivity: Continuous wires

Split Ring Resonator

(SRR), Pendry,

1999

Short-slabs-pair, Shalaev,

2002

m 1/ LC

j

L

C

Designing left-handed metamaterials TETYTETY

Microwave (mm-scale) structures TETYTETY

780 nm1.4 μm

Fabricated in MRG

Micro and nano-scale structuresTETYTETY

• 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 TETYTETY

• 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 TETYTETY

Silver in polyimide

Optics Letters 30, 1348 (2005)

m

Five Five layers !layers !

μ<0 @ ~6 THz

Fabricated in Crete

Optical metamaterials

n<0 @ 1.4 μm

Re(n)=-0.6 @ 780 nm

THz and optical structuresTETYTETY

• Saturation of response frequency in small length scales (a<500 nm)•Vanishing of negative permeability band-width•Weakening of permeability resonance

a: u.c. size

Al metalGlass substrate

Reducing a

Optical metamaterials

Results not affected by metal losses

“Magnetic” metamaterials response in high frequencies TETYTETY

No negative permeability at arbitrarily high

frequencies

Optical metamaterials with gainTETYTETY

Gain atoms (4-level) embedded in host medium: In Finite Difference Time Domain Method are driven oscillators which couple to the local E field

EPPP

2

2

2

Ntt aa

0pump10

10

10

1

21

21

21

2

32

32

32

30pump

3

1

1

NN

t

N

N

t

N

t

N

N

t

N

t

N

NN

t

N

a

a

PE

PE

Rate equations:

Driven oscillators:

0N

1N

2N

3N

pumpLasing ωa

323 /N

101 /N

212 /N

ta

P

E1

σa is the coupling strength of P to the external E field and ΔN=N2-N1 Phys. Rev. B: 79, 241104 (Rapid) (2009)

t

B

Ett

PE

H 0

Maxwell’s equations:

C. Soukoulis’ collaboration with Karlsruhe and MRG

Same method for examining lasing threshold in photonic crystals (with M. Farsari)

• 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

Main investigation aims/directions TETYTETY

• 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

Main investigation aims/directions TETYTETY

PRB, 79, 161102 (R) (2009)

Collaboration with S. Tzortzakis’ groupBlue-shift tunable metamaterials

& Dual-band switches

The principle:

Switchable and tunable metamaterialsTETYTETY

UV

• 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

Main investigation aims/directions TETYTETY

n

Besides negative index:•Polarization rotation •Circular dichroism

Chiral structure: not-identical to its mirror image

•Different index for left- and right-handed circularly polarized waves

•Alternative path to achieve negative index

Lef t-handed

Ri ght-handed

i

i

D E H

B H E

Negative indexLarge polarization rotationLarge circular dichroism

New designs/approaches

Negative refractive index in chiral mediaTETYTETY

• 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

Main investigation aims/directions TETYTETY

•Super-lensing in anisotropic “negative” metamaterials

•Electromagnetically-induced-transparency in metamaterials

•Repulsive Casimir force in chiral metamaterials

Novel phenomena and possibilities in metamaterialsTETYTETY

• 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

Besides metamaterials ?Photonic crystalsPlasmonic systems

Main investigation aims/directions TETYTETY

k

E

HLattice constant a = 840 nmWidth of square hole: w = 540 nm Emission frequency: 100 THzDielectric constant of gain: 11.7

Thickness: 8400 nm

Gain

Air

Lasing threshold for 2D inverse photonic crystals (TM)TETYTETY

Much lower lasing threshold (at upper band edge) than bulk gain

• 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

Besides metamaterials ?Photonic crystalsPlasmonic systems

Thank you.

Thank you.

Main investigation aims/directions TETYTETY