View
215
Download
0
Category
Preview:
Citation preview
1
Plasmonics in random media
Cid B. de Araújo
Departamento de Física
Universidade Federal de Pernambuco
Recife
Brazil
2
“Science and technology that deals with the generation, control, manipulation, and transmission of plasmonexcitation in metal nanostructures”
Plasmonics
7
Surface plasmon frequency
(depend on shape, size and material)
0
0
0
2
3EE
in
in
2
2
1
p
in
021
p
applied electric field
Drude dielectric function
SP frequency is therefore:
host dielectric function
(This assumes particle is small compared to wavelength.)
nanosphere
8
Silver in aqueous colloid
2
2
2
1
22/3
29
m
mext Vc
C
Extinction coefficient
nanospheres
Mie theory 1908 (dipole aproximation)
9
t = 20 nm
5 nm
15 nm10 nm
Metal nanoshell colloids
Plasmon resonance tunable by core and shell dimensions
11
Field increases by 24 for
particles with diameter
of 20 nm.
Coupled nanoparticles
Kottmannn, Martin Opt. Lett 2001
Intensity enhancement > 500
12
More complex nano-structures
n=1.5
600nm
40 nm
Plasmonic nanolens:
First proposed by Li, Stockman &
Bergman, PRL (2003)
Bidaut, JACS 2008
Log enhancement
13
•Plasmon enhanced fluorescence
•Third-order nonlinear optics in plasmonic materials
•Random lasers
Metal-dielectric nanocomposites
Surface plasmon resonances may increase NL response
Scale size of inhomogeneities << optical wavelength
Optical susceptibility can be described by volume averaged quantities
15
Fractals structures and hot spots
Shalaev et al.Marder et al.
Optical glasses doped with trivalent rare earth ions
containing silver or gold NPs
18
59 PbO – 41 GeO2
1 2 3 4 5 60,0
5,0
10,0
15,0
20,0
25,0
30,0
35,0
40,0
Diâmetro da nanoparticulas (nm)
Fre
qu
ên
cia
(%
)
Frequency upconversion in Er3+ doped PbO-GeO2
glasses containing silver nanoparticles
Appl. Phys. Lett. 90, 081913 (2007)
400 600 800 1000 1400 1600
0,2
0,4
0,6
0,8
1,0
400 450 500 550
0,1
0,2
0,3
0,4
Abso
rptio
n (
a.u
.)
Wavelength (nm)
Absorp
tion s
pectr
a
Wavelength (nm)
no silver NP
16h
39h
51h
4F
9/2
4G
11/2
4I
9/2
4I
11/2
4I
13/2
4S
3/2
2H
11/2
4F
7/2
Plasmon Ag4F
3/2+
4F
5/2
2G
9/2
19
980 nm
980 nm
53
0 n
m
54
7 n
m
68
0 n
m
Infrared laser
100% enhancement
Nanothermometer
Infraredlaser
20
Tellurium glass with silver NPs doped with Pr3+ or (Tb3+-Eu3+) or Tb3+:
J. Appl. Phys. 105, 103505 (2009).J. Appl. Phys. 104, 093531 (2008).J. Appl. Phys. 103, 093526 (2008).
Gemanate glass doped with Eu3+ or (Yb3+-Er3+) containing silver, gold or copper NPs:
Appl. Phys. Lett. 94, 101912 (2009).Appl. Phys. B 94, 239 (2009).Appl. Phys. Lett. 92, 141916 (2008).
21
Nonlinear OpticsInteraction light-matter under circunstances that
the linear superposition principle is violated
Optical polarization Dipole moment per unit volume
P = o [ (1) E + (2) E2 + (3) E3 +...]
(n) 0 , n = even (centro-symmetric media)
P induces changes in the speed of light in the medium
and new frequencies may be generated
22
Nonlinear Optics hold great
promise for applications such as:
but the lack of appropriate materials do notallow the implementation of many ideas alreadypresented
•All-Optical Switching
•Optical Limiting
•Optical Sensors
•Lasers and Amplifiers
23
n = n0 + n2 I(r)
n2 > 0 self focusing n2 < 0 self defocusing
Tn2I
Z-scan technique
n2 < 0
n2 > 0
Nonlinear refraction
Nonlinear absorption
= 0 + 2 I(r)T 2 I
24
Local field enhancement
Surface plasmon resonance
Colloids containing metallic nanoparticles
)3()3(22)3(hostNPeff f
)(2)(
)(3
hNP
NP
0)(2)(Re sphspNP
Filling fraction
25
Sodium citrate
PVA
PVP
Influence of stabilizing agents and dipole moment of solvents
Susceptibility changes by more that 100% for PVA and PVP
Z – scan532 nm 80 ps 5 Hz
J.O.S.A. B 24, 2136 (2007)
PVP PVASodium
citrate
Third order susceptibility of silver colloids
Applied Physics B 92, 61 (2008)
Ag
26
50 nm
0 2 4 6 8 100
20
40
60
80
100
120(b)
average diameter: 3.9 nm
Num
ber
of part
icle
s
Diameter of particles (nm)
5
nm
hi
hi
2
f
fheff
1
31
NL susceptibility of silver nanoparticles in CS2
Competing processes betweennonlinearities of the constituents
Silver NPs capped with dodecanethiol
27
0.0 1.0 2.0 3.0 4.0
-4.0
-2.0
0.0
2.0
4.0(a)
n 2 (
10
-14 c
m2/ W
)
f ( 10
-5 )
0.0 1.0 2.0 3.0 4.0
-2.0
-1.5
-1.0
-0.5
0.0
(b)
2 (
cm
/GW
)
f ( 10
-5 )
2220)3(105.3109.2 ih
m2/V2
Control of spatial and temporal profile of optical beams(Space and temporal solitons)
NL Maxwell Garnet model
)3()3()3()( NPheff biaf
2216)3( 10)9.13.6( VmiNP
J.O.S.A. B 22, 2444 (2005)
28
First observation of high-order nonlinearities in Ag aqueous colloids
NL refractivebehavior
Nonlinear absorption
Z-scan 80 ps @ 532 nm (single pulses 5 Hz)
-15 -10 -5 0 5 10 15
0.92
0.96
1.00
1.04
1.08
1.12
1.16
1.20
(b)
No
rmalize
d t
ran
sm
itta
nce
Z (mm)
-15 -10 -5 0 5 10 150.85
0.90
0.95
1.00
1.05
1.10
1.15
(a)
No
rmalized
tra
nsm
itta
nce
Z (mm)
J.O.S.A. B 24, 2948 (2007)
3rd
order
T I
InT 2
IT 2
29
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6-7.0
-6.0
-5.0
-4.0
-3.0
-2.0
-1.0
0.0
1.0
n2 (
x10
-18 m
2/ W
)
f ( x 10
-4 )
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6-3.0
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
0.5
2 (
x10
-10 m
/ W )
f ( x 10
-4 )
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
n4 (
x10
-30 m
4/ W
2 )
f ( x 10
-4 )
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6-2.0
0.0
2.0
4.0
6.0
8.0
4 (
x10
-23 m
3/ W
2 )
f ( x 10
-4 )
High order nonlinearities also depend linearly with f
[Up to (9)]
3rd. order nonlinearity
5th. order nonlinearity
NLrefraction
NL absorption
31Appl. Phys. Lett. 92, 141916 (2008)
PbO-GeO2 film with copper NPs
Influence of the Surface Plasmon Resonance
No crossing
Laser pulses
150 fs
32
0 50 100 150 200 2500.94
0.96
0.98
1.00
1.02
1.04
1.06
No
rma
lize
d T
ran
sm
itta
nc
e
Time (us)
Peak
Valley
250 500 750 1000 1250 1500 1750 2000
0
1
2
Metal Nanoshell
A
bs
orb
an
ce (
arb
tra
ry u
nit
s)
Wavelength (nm)
Laser 1560 nm
-5 -4 -3 -2 -1 0 1 2 3 4 5
0.98
0.99
1.00
1.01
1.02
1.03
No
rma
lize
d
Tra
ns
mit
an
ce
.
Z/Z0
time = 20us
Nonlinear refraction at 1560 nmNanoshells silica-gold
Inner radius: 50 nm
Outer radius: 70 nm
n2 = 20 x 10-14 m2/W
Thermally - managed eclipse Z-scan
Laser pulses
60 fs
33
Silver NPs in-situ growth within crosslinked poly (ester – co - styrene) induced by UV irradiation aggregation control with exposition time
Silver NPs (5-10 nm)
J. Phys. Chem. Solids 68, 729 (2007)
HYBRID COMPOSITES
35
2 x 10-3 M 1011 particles / cm3
Mean free path: 120 m @ 532 nm
and 140 m @ 650 nm
Generated photons make a random
pathway due to reflection by the TiO2
particles
Random lasers (lasers without mirrors)
Lawandy et al. Nature 1994
Intensity
100 0 mJ 15
36
560 580 600 620 640 660 680 700
0,0
0,2
0,4
0,6
0,8
1,0
Inte
nsi
da
de N
orm
ali
zad
a
(nm)
2 mW
15 mW
160 mW
560 580 600 620 640 660 680 700
0
20000
40000
60000
80000
100000
120000
140000
160000
In
ten
sid
ad
e (
a.u
.)
(nm)
(2 mW) (15 mW) (150 mW)
Our polymers with TiO2 particles
Line narrowing
Rh6G
TiO2 particles
Rhodamine 6G 2 x 10-3 M 1011 particles / cm3
Mean free path: 120 m @ 532 nm and 140 m @ 650 nm
Threshold like behavior
38
Is it possible to operate a random laser with directional emission but using no mirrors?
Hollow core fiber
Refractive index profile
Transverse feedback: total internal reflectionAxial feedback: multiple scattering
Colloid with Rh 6G +TiO2
Photonic band gap fiber
39
100 times more efficient than conventional random lasers
First Random Fiber Laser
Phys. Rev. Lett. 99, 153903 (2007)
41
Upconversion Random Laser
Normalized UV signal 381 nm
Above threshold
30 mFluoroindate glass powder
42
NEXT STEP
Random fiber laser
based on
Nd3+ doped nanocrystals + metal
nanoparticles
combined effects of multiple light scattering with local field enhancement due to surface plasmons
reduced threshold
43
Plasmonics: a fundamentally multidisciplinary enterprise
Plasmon-enhanced spectroscopies for chemical & biodetection
100 400 700 1000 1300 1600 1900
Raman Shift (cm-1)
Fundamental science of metallic nano-optical components
Optical interconnects in next-generation computer chips
Light harvesting for energy
conversion
wavelength (nm)
nanoshellsIn vitro and in vivo
Biomedical applications
Plasmonic solar cells
SPASER
44
Web of Science 01/Sept/2009Keywords:plasmonics; surface plasmons;surface plasmon polaritons;localized surface plasmons.
45
Web of Science 01/Sept/2009Keywords:
plasmonics; surface plasmons;
surface plasmon polaritons;
localized surface plasmons.
46
Ernesto Valdez Rodriguez (D. Sc. 2007) – Research Associate
Antonio Marcos Brito-Silva – D. Sc. student - Materials Science
Denise Valença – M. Sc. student – Physics
Euclides C. Lins de Almeida - D. Sc. student - Physics
Gemima Barros Correia – D. Sc. student – Materials Science
Hans A. Garcia Mejia - D. Sc. student - Physics
Marcos André Soares de Oliveira – D. Sc. student – Physics
Milena Frej – M. Sc. – Physics
Ronaldo P. de Melo – D. Sc. student – Materials Science
Tâmara P. R. de Oliveira - D. Sc. student - Physics
Jamil Saade – D. Sc. Student – Materials Science
Renato B. Silva – M. Sc. Student – Materials Science
A. Galembeck - UFPE
L. Kassab – FATEC – SP
M. Poulain – Rennes – France
Y. Messaddeq – UNESP - SP
47
3
042
m
m
R
Surface plasmons:electromagnetic resonances in the visible
Localized plasmon
oscillation
2/1
dm
dmx
ck
Propagating surface plasmon
polariton (SPP)
dielectricmetal
dielectric metal
Recommended