Post on 21-Dec-2015
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