B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 1
Plasmonique intégrée pour circuits photoniques à haute densité
Mickaël Février, Lukas Halagacka, Matthias Grangier, Yida Wen, Philippe Gogol, Abdelhanin Aassime, David Bouville, Navy Yam, Robert Megy, Béatrice Dagens
Coll: LNIO (UTT) et CEA-LETI
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 2
Integrated plasmonic : why ?
µfluidic channel
Optical source Optical detectorSensor area
Integrated bioplasmonic sensor
Specific functions, miniaturized functionsEfficient excitationSpatial separation of « active function » and excitation/detection system
Complex circuits Efficient devices
Optical interconnects, optical circuitry, nanoantennasIsolators, circulators
Isolator
Circulator
Principle: enhanced properties thanks to nanostructuration and guiding effects
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 3
Outline
• Integrated plasmonic : why ?
• State of the art
• Localized surface plasmon chains
• SOI - LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
Gold nanoparticles
SOI waveguide
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 4
State of the art : interfacing SOI and plasmonic waveguide
• reflexionslosses• Coupling efficiency between 15%
and 30%
Chen et al, Opt. Lett., 31, 2133, 2006
Tian et al, APL, 95, 013504, 2009
Briggs et al, Nano. Lett., 10, 4851, 2010
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
Butt-joint coupling
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 5
State of the art : interfacing SOI and plasmonic waveguide
Sederberg et al, APL 96, 121101, 2010
Delacour et al, Nano. Lett., 10, 2922, 2010• Reduced reflections• Coupling efficiency: 60% to 70%
Evanescent coupling
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 6
State of the art : localized surface plasmons nanoparticles deposited on a waveguide
Quidant et al, PRB 69, 085407 (2004)
• successive metallic NP: correlated excitation through underlying dielectric waveguide (like in Bragg grating)
• but no direct coupling between NP
Bragg grating made of metallic nanoparticles
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 7
Localized surface plasmon (LSP) chains
Simsek, Optics Express , 18, 1722, 2010
Plasmonic resonance generated by an
electromagnetic excitation in a metallic nanoparticle
(subwavelength dimension)
Excited particle= oscillating dipole
Near field excitation of the nearest particle:
electromagnetic energy propagation
Plasmonic resonance controlled by the
size, shape, position of nanoparticles
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 8
Ellipsoidal MNP polarisability
Response of MNP to electromagnetic field depends on polarisability a (for isolated MNP or for MNP assembly)
Ep d
04
Polarisability a includes static response (dielectric cstt, shape of the ellipsoid)
But also radiative effects (dimensions of the NP with respect to wavelength, retardation effects, …)
)(33,0
dmud
dmzyxu Laaa
1
2
2
3
3
,0 3
21
vavi
uuu
with
0 2/1
,,
22 )()(2
zyxmmu
zyxu
qaqa
dqaaaL
zyxu aaaa
zyxu
,,
,,
x
zy
(ellipse semi-axis)
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
ed
em
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 9
Ellipsoidal MNP polarisability
polarisability a is sensitive to MNP environment, shape and dimensions
ay= 40110 nm
Po
lari
sab
ilit
y (i
mag
par
t)
ax=40nm, az=15nm
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
x
zy
ay
ed
em
Eext
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 10
(LSP) chains design
Weber et al, PRB, 70, 125429, 2004Koenderink et al, PRB, 74,033405, 2006
3 2 330
/( ) 14
ˆ ˆ3( )1 ˆ ˆ( )² m mm mN i n md c
m n
extn n
i n m dc n m d c n m d
e
r p r p p r p rp E
Model “Couple Dipole Approximation” (in homogeneous medium)
• each nanoparticle = one point, with polarisability a
• radiative losses, NP geometry, gold index (Drude model)
• long and short distance interaction
P: dipolar moment
E: external excitation
α: polarisability
ω: pulsation
d: interparticle distance
Contribution of other MNP 1/r, 1/r² and 1/r3 interactions
Gives the excitation profile along the finite chain (|pn|²~dissipated ohmic power)
Defines collective oscillation of chain dipoles of the infinite or finite chain : eigenmodes (En
(ext)=0) in homogeneous medium: dispersion curve
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 11
(LSP) chains modelling (in homogeneous medium)
Dispersion curves of the infinite chain :
Dispersion curves of the finite chain :
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
20 MNP chain in homogeneous media
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 12
Designed and realized device
• Design: analytical and then FDTD models• Telecom wavelength, TE mode: ellipsoidal shape• E-beam lithography (alignment) + lift-off process• 30 nm thick gold nanorods
2 ax
2 ay
2 ay~ 220 nm
2 ax~ 80 nm
Localized surface plasmon excitation ? Chain = waveguide ?
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 13
20 MNP: transmission spectrum
• Resonance transmission minimum• « noise »: FP modes• FDTD simulation (experimentally fitted Drude model): 5dB extra losses
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
Transmission setup(IEF)
Chain excitation ? Coupling mechanisms ?
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 14
Near-field : traNSNOM(LNIO, UTT)
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 15
M. Fevrier et al. Nano Lett. 12, 1032, 2012
(a)(b) (c)
(a)
(b)
(c)
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 16
Dispersion curves
FDTD calculation extracted dispersion curve of the 20 MNP chain on SOI
Coupled modes (anticrossing) chain=waveguide
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
Dispersion curves of a chain in homogeneous medium and of the SOI waveguide
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 17
From 5 to 50 MNP chain
10 MNP
20 MNP 50 MNP
5 MNP
- transmission: similar spectral shape, wider for longer chains- much lower transmission at 5MNP: cavity effect
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 18
From 5 to 50 MNP chain
l=1475 nm
5MNP, 1325 nm
20MNP, 1475 nm 50MNP, 1465 nm
10MNP, 1321 nm
Intensity profiles at transmission minimum
- 20 and 50 MNP: clear waveguide coupling- 10 MNP: intermediate case- 10 to 50 MNP: same coupling length
- 5 MNP: too short for re-coupling ; total energy transfer into the fourth MNP (<500nm)
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 19
Dipole excitation: experimental validation
5MNP, 1325 nm
20MNP, 1475 nm
Very short chains (5MNP) sufficient to implement plasmonic functions
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 20
Record coupling length
2LcLc ≈ 560 nmκ ≈ 2805 mm-1
Waveguides Coupling length (Lc)
SOI/nanoparticle chain ≈ 560 nm (measure, Fevrier et al. Nano Lett.)
SOI/delocalized plasmonic waveguide
≈ 1 µm (measure, Delacour et al. Nano Lett.)
2 dielectric waveguides ≈ 100 µm (theory, Sun et al. Optics Lett.)
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 21
LSP chain on Si3N4 waveguide
Waveguide coupling Longer coupling length in Si3N4 waveguide case
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
M. Février et al, submitted to JLT
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 22
Excitation near or far of the light line
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
Lc = λ/[2(neff antisym − neff sym)]
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 23
Strong interaction due to device geometry
Mode distortion, especially in dielectric waveguide
M. Février et al, submitted to JLT
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 24
Excitation up to « non guided » mode
Low guiding in Si3N4
Antisymmetric supermode with index higher than material index
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
M. Février et al, submitted to JLT
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 25
Excitation up to « non guided » mode
appears on transmission curve
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 26
Guiding based on resonances and near-field coupling
1rst Brillouin zone
chain
SOI
dkb
kb=2pd
d=150 nm
Spatial harmonics : - generated by chain periodicity - includes decreasing phase contribution- may be as intense as fundamental
component
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 27
Specific collective chain modes
FDTD
1rst et 2nd Brillouin zones
Strong excitation of spatial harmonics in chain waveguide
-
2,561,6
Heterodyne SNOM (LNIO, UTT)
-40 -30 -20 -10 0 10 20 30 40
NeffA. Appuzzo, accepted for publication in Nano Letters
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 28
Biochips : plasmonics waveguides
Silice Si02
SAM thiol/orSAM silane
/ SiO2or
Bio-plasmonics for molecular interaction with localized plasmons
Possible detection in transmission
Compatibility with further integration with “lab-on-chip” systems: thiols molecules grafting on gold; thiols can “capture” element to be detected
Plasmonics response strongly modified by the presence of these elements (molecules, ...)
• Integrated plasmonic : why ?
• State of the art• Localized
surface plasmon chains
• SOI- LSP chain interfacing
• From long to short plasmonic chains
• Back to waveguide coupling
• Chain mode harmonics
• Application to biosensing
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 29
Toward biosensing
Calculation: chain of 5 gold nanoparticles coated with dielectric material.
experiment
Mickaël Février, et al, « Integration of short gold nanoparticles chain on SOI waveguide toward compact integrated bio-sensors, » Optics Express Vol. 20, Iss. 16, pp. 17402–17409 (2012)
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 30
Conclusion and perspectives
• Integration of localized plasmon waveguide on SOI demonstrated, at telecom wavelength
• Several efficient excitation and propagation regimes identified• Very short chains (5MNP) sufficient to implement plasmonic functions• Similar behaviours with SiN guide (compatible with visible wavelength)
Short chain = reduced losses, compactness Plasmonic= energy concentration (non-linear functions, sensing, …) Toward magneto-plasmonic (Au/Co/Au)
B.Dagens, Journées thématiques GdR Ondes, Grenoble, 17 et 18 janvier 2013 31
Thanks for your attention