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

3

Notre Dame de Paris

Cu, Ag, Au

Surface plasmons in nanoparticles

4

5

Boyd , Swieca School 2004

6

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

10

Near-field intensity

Spatial extension: 10-50 nm

Schatz et al.

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

14

Plasmon enhanced luminescence

)()(),( PLradexabsPLexPL

ATOM

Novotny et al. PRL 2006

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

16

No Au NPs

17

Enhanced luminescence

at 614 nm

(excitation at 405 nm)

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

30

Thermally managed eclipse Z-scan

Opt. Express 15, 1712 (2007)

Large rep rate 70 MHz

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

34

Lithography

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

37

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)

40

575nm (4I9/2 → 2G7/2)

Nd3+ doped fluoroindate glass

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

48

Heat treatment: 23 h

Pr3+ in Ga10Ge25S65 with Ag nanoparticles

JAP 103, 103526 (2008)

49

)()( 4

3

2

1

4

3

0

3 HDHP

23 hours

Increase by 130 %

Heat treatment