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Transcript of Optical near-field control of nanoresonators [email protected] Near Field Optics Group...
Optical near-field control of nanoresonators
Near Field Optics GroupOMR ICB - Université de Bourgogne
Benoit Cluzel, Loïc Lalouat, Frédérique de Fornel
Philippe Velha, Emmanuel Picard, Thomas Charvolin, Emmanuel Hadji
Philippe Lalanne
David Peyrade
Collaborations
Nicolas Louvion, Christian Seassal, Ségolène Callard
ACI NR63 « CHABIP »
Introduction
Optical resonators
Light confinement inside a volume V with an efficiency Q
For single photon sources, ultra low treshold lasers, enhanced light matter-interactions.
Figure of merits : Q/V
h
Introduction
Near-Field control of optical resonators
- to probe the electromagnetic field confinement
- to manipulate mechanically the confinement ?
Outline
1/ Resonators of nanophotonics
2/ Optical near-field microscopy
3/ Near-Field Probing of light confinement
4/ Near-Field Manipulation of light confinement
1/ Resonators of Nanophotonics
Kippenberg et al, Nature 421 (2003) Akahane et al, Nature 425 (2003)
Refraction Diffraction
Photonic crystal resonators
Spherical/Toroïdal resonators
Light confinement with ultra- high Q
Q~106-108 V~50µm3
Light confinement in ultra- small V
Q~104-106
V~0.1µm3
50µm 1µm
2/ Optical near-field imaging of nanoresonators
Near-field probe
Exponential decay of the fieldDecay length ~100nm
OPTICAL NEAR FIELD
Evanescent wave collection & mapping+
Topographical pictures
Optical Microscopy :Propagative waves imaging : Resolution > /2 (Rayleigh limit)
Near-field Microscopy :Evanescent waves imaging : Sub- wavelength resolution
n1
n2
n1
InGaAs QWs
Optical pumping=780nm
PL =1550nm
Si
SiO2
InP
3/ Near-field probing of light confinement
Experimental approach:
1300 1400 1500 1600 17000,00
0,01
0,02
0,03
PL
in
ten
sit
y (
a.u
.)
Wavelength (nm)
4µm
4µm
4µm
1µm
1µm
Resolution ~ /10 < Rayleigh limit
3/ Near-field probing of light confinement
Experimental results:
3/ Toward a Near-field control of confined light
What about the effect of the near-field probes ???
3/ Toward a Near-field control of confined light
General assumptions: 1- Since the probe volume remains largely lower than the cavity volume
2- The losses introduced by the presence of the probe are lower than the cavity losses
The probe is not a perturbative element of the system
But What happens if ????
Let consider a state of the art nanocavity with:
An ultra low-volume : V=(/n)3
A high Q-factor: Q~104-105
1µm
3/ Toward a Near-field control of the confined light
3/ Toward a Near-field control of the confined light
« pump – probe » experiments with a near-field tip
Light in
IT()
Tip up
z >100nm
~100nmSiO2
z =4nmNear-FieldInteraction
Tip down
1560,5 1561,0 1561,50
1
2
I T(z
) (
V)
Wavelength (nm)
3/ Basics of Optical Near-Field interactions
The probe acts as an optical path length modulator
Q=12000
1560,5 1561,0 1561,50
1
2
I T(z
) (
V)
Wavelength (nm)
Q=11000
Losses introduced by the probe << Cavity Losses
3/ Basics of Optical Near-Field interactions
Evanescent interaction between probe and cavity
3/ Optical Near-Field interactions mapping
1560,5 1561,0 1561,5
1
I T(z
) (
V)
Wavelength (nm)
downup
600nm
Interaction map @ up
600nm
Interaction map @ down
2E
Dielectric pertubation of the Electric field
3/ Optical Near-Field interactions control
Near-Field Switch
Time scale for switching limited by mechanical
resonance
=>could excess the MHz range with the integration of
cantilevers
Conclusion
From Passive to Active Near Field Optics
Sub- probing of the light
confinement in nanoresonators
Sub- manipulation of the light confinement
in nanoresonators
4µm
Publications:Gérard et al, Opt. Lett. 27, 2002Cluzel et al, App. Phys. Lett. 85, 2004Louvion et al, Phys Rev. Lett. 94 2005Cluzel et al, J. App Phys. 98, 2005 Cluzel et al, App. Phys. Lett. 88, 2006
A post-doctoral position available now!
In the Near-Field Optics Group (Université de Bourgogne, France)
Contact: [email protected] [email protected]