-
Jérémie Margueritat,
Alexandre Bouhelier,
Laurent Markey, Gérard Colas des Francs,
Alain Dereux,
Stéphanie Lau-Truong,
Johan Grand,
Georges Lévi,
Nordin Félidj,
Jean Aubard,
Eric Finot
The Journal of Physical Chemistry C 11/2012; 116:26919-26923. · 4.80 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In this work, we demonstrate propagating surface plasmon polariton (SPP) coupled photoluminescence (PL) excitation of single-walled carbon nanotube (SWNT). SPPs were launched at a few micrometers from individually marked SWNT, and plasmon-coupled PL was recorded to determine the efficiency of this remote in-plane addressing scheme. The efficiency depends upon the following factors: (i) longitudinal and transverse distances between the SPP launching site and the location of the SWNT and (ii) orientation of the SWNT with respect to the plasmon propagation wave vector (k<sub>SPP</sub>). Our experiment explores the possible integration of carbon nanotubes as a plasmon sensor in plasmonic and nanophotonic devices.
Optics Letters 11/2012; 37(22):4711-3. · 3.40 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Amplifying local electromagnetic fields by engineering optical interactions between individual constituents of an optical antenna is considered fundamental for efficient nonlinear wavelength conversion in nanometer-scale devices. In contrast to this general statement we show that high field enhancement does not necessarily lead to an optimized nonlinear activity. In particular, we demonstrate that second-harmonic responses generated at strongly interacting optical gap antennas can be significantly suppressed. Numerical simulations are confirming silencing of second-harmonic in these coupled systems despite the existence of local field amplification. We then propose a simple approach to restore and amplify the second-harmonic signal by changing the manner in which electrically-connected optical antennas are interacting in the charge-transfer plasmon regime. Our observations provide critical design rules for realizing optimal structures that are essential for a broad variety of nonlinear surface-enhanced characterizations and for realizing the next generation of electrically-driven optical antennas.
Optics Express 05/2012; 20(10):10498-508. · 3.59 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We report on the excitation of propagating surface plasmon polaritons in thin metal films by a single emitter. Upon excitation in the visible regime, individual semiconducting single-walled carbon nanotubes are shown to act as directional near-infrared point dipole sources launching propagating surface plasmons mainly along the direction of the nanotube axis. Plasmon excitation and propagation is monitored in Fourier and real space by leakage radiation microscopy and is modeled by rigorous theoretical calculations. Coupling to plasmons almost completely reshapes the emission of nanotubes both spatially and with respect to polarization as compared to photoluminescence on a dielectric substrate.
Nano Letters 12/2011; 12(1):177-81. · 13.20 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Using dual-plane leakage radiation microscopy, we investigate plasmon propagation in individual penta-twinned crystalline silver nanowires. By measuring the wavevector content of the light emitted in the substrate, we unambiguously determine the effective index and the losses of the mode propagating in these structures. The experimental results, in particular, the unexpectedly low effective index, reveal the direct influence of the nanowire crystallinity and pentagonal structure on the observed plasmon modes. By analogy with molecular orbitals of similar symmetry, the plasmon modes are also determined numerically in good agreement with the observed values. We further investigate the effect of wire geometry (length, diameter) on the effective index and propagation loss. Our results show that, beyond dissipation concerns, the morphological and structural control obtained in crystalline colloidal plasmonic nanostructures can be exploited to finely tune their optical properties.
ACS Nano 06/2011; 5(7):5874-80. · 10.77 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The experimental observation of a one-dimensional evanescent wave supported by a 90◦ metal edge is reported. Through a measurement of in-plane momenta, we clearly demonstrate the dimensional character of this surface wave and show that it is non-radiative in the superstrate. Excitation conditions, lateral extension and polarization properties of this wave are discussed. Finally, we explore the effect of the surrounding dielectric medium and demonstrate that a single edge can sustain distinct excitations.
Optics Express 03/2011; 19(6):5303-12. · 3.59 Impact Factor
-
Gérard Colas des Francs
[show abstract]
[hide abstract]
ABSTRACT: The non-radiative coupling of a molecule to a metallic spherical particle is approximated by a sum involving particle quasistatic polarizabilities. We demonstrate that energy transfer from molecule to particle satisfies the optical theorem if size effects corrections are properly introduced into the quasistatic polarizabilities. We hope that this simplified model gives valuable information on the coupling mechanism between molecule and metallic nanostructures available for, e.g., surface enhanced spectroscopy signal analysis.
International Journal of Molecular Sciences 09/2009; 10(9):3931-6. · 2.60 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The spatial confinement of surface plasmon polaritons is a promising route for realizing optical on-board interconnects. However, mode losses increase with the confinement factor. To overcome this road block, we investigate propagation assisted by stimulated emission in a polymer strip-loaded plasmonic waveguide doped with nanocrystals. We achieve 27% increase of the propagation length at telecom wavelength corresponding to a 160 cm(-1) optical gain coefficient. Such a configuration is a step toward integrated plasmonic amplifiers.
Nano Letters 09/2009; 9(8):2935-9. · 13.20 Impact Factor
-
Johann Berthelot,
Alexandre Bouhelier,
Caijin Huang,
Jérémie Margueritat, Gérard Colas-des-Francs,
Eric Finot,
Jean-Claude Weeber,
Alain Dereux,
Sergei Kostcheev,
Hicham Ibn El Ahrach,
Anne-Laure Baudrion,
Jérôme Plain,
Renaud Bachelot,
Pascal Royer,
Gary P Wiederrecht
[show abstract]
[hide abstract]
ABSTRACT: Optical antennas are elementary units used to direct optical radiation to the nanoscale. Here we demonstrate an active control over individual antenna performances by an external electrical trigger. We find that by an in-plane command of an anisotropic load medium, the electromagnetic interaction between individual elements constituting an optical antenna can be controlled, resulting in a strong polarization and tuning response. An active command of the antenna is a prerequisite for directing light wave through the utilization of such a device.
Nano Letters 09/2009; 9(11):3914-21. · 13.20 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The new optical concepts currently developed in the research field of plasmonics can have significant practical applications for integrated optical device miniaturization as well as for molecular sensing applications. Particularly, these new devices can offer interesting opportunities for optical addressing of quantum systems. In this article, we develop a realistic model able to explore the various functionalities of a plasmon device connected to a single fluorescing molecule. We show that this theoretical method provides a useful framework to understand how quantum and plasmonic entities interact in a small area. Thus, the fluorescence signal evolution from excitation control to relaxation control depending on the incident light power is clearly observed.
The Journal of Chemical Physics 07/2007; 127(3):034701-034701-5. · 3.33 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: When the probe tip of a near-field optical microscope illuminates nanoparticles with marked absorption bands, a large number of photons are absorbed before reaching the detector. These energy losses enhance the dark contrast usually observed in the vicinity of metallic nanoparticles. We demonstrate theoretically that this phenomenon can be exploited to image, in the optical frequency range, dissipative domains with a nanometer scale resolution. Simulations performed with noble-metal particles indicate that the detected signal significantly drops down when the excitation frequency is approaching the plasmon resonance of the particles.
The Journal of Chemical Physics 12/2005; 123(17):174709. · 3.33 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In this paper we study the properties of microring resonator structures fabricated with high-index-of-refraction dielectric material. These structures concentrate light and can produce very strong optical potential gradients. They are of great interest for the trapping, manipulation and transport of cold atoms near surfaces. The study consists of two parts: in the first part we investigate the symmetry properties of the resonator response for simple models of the microring structures. In the second part we present detailed numerical calculations of the actual spectra for realistic microfabricated structures. We employ the direct space integral equation method (DSIEM). This method, based on a volume integral solving procedure, has already been found to cope successfully with nonresonant dielectric nanostructures. Such ab initio investigations of the optical near-field distributions only require a specification of the frequency-dependent dielectric constant and the precise shape of the fabricated structures. Consequently, these calculations can stand alone, or complement and inform anticipated experimental studies.
Nanotechnology 07/2004; 15(9):1200. · 3.98 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A fluorescing structure (made of one or several molecules) can be considered as an ideal point source of light for use in a near-field optical microscope [Michaelis et al., Nature 405, 325 (2000)]. This paper discusses how the image–object relationship is made easier to understand by introducing the concept of photon local density of states (LDOS). Specifically, we show that the LDOS determined by Green’s dyadic calculations provide the relevant interpretation of the images recorded with a single fluorescing molecule as source of light. Recent experimental results are analyzed on this basis. © 2002 American Institute of Physics.
The Journal of Chemical Physics 09/2002; 117(10):4659-4666. · 3.33 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The polarization state of the optical electromagnetic field lying several nanometers above complex dielectric-air interfaces reveals the intricate light-matter interaction that occurs in the near-field zone. From the experimental point of view, access to this information is not direct and can only be extracted from an analysis of the polarization state of the detected light. These polarization states can be calculated by different numerical methods, well suited to near-field optics. In this paper, we apply two different techniques (localized Green's function method and differential theory of gratings) to separate each polarization component associated with both electric and magnetic optical near fields produced by nanometer sized objects. A simple dipolar model is used to get an insight into the physical origin of the near-field polarization state. In a second stage, accurate numerical simulations of field maps complete data produced by analytical models. We conclude this study by demonstrating the role played by the near-field polarization in the formation of the local density of states.
Physical Review E 04/2002; 65(3 Pt 2B):036701. · 2.26 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Experimental observation of light coupling between TiO2 integrated waveguides of subwavelength cross section and pure three-dimensional evanescent light fields is reported. This near-field optical phenomenon is produced by controlling the location of the focusing of a laser beam totally reflected at the surface of the sample. The phenomenon is observed in direct space with a photon scanning tunneling microscope. Dielectric ridges several tens of micrometers long have been efficiently excited with this technique. Upon excitation, the extremities of the linear dielectric wires display intense light spots localized both inside and around the ridge. For ridge lengths up to 30μm, the observed phenomenon has been reproduced numerically with a parallel implementation based on the three-dimensional Green dyadic method.
Phys. Rev. E. 11/2001; 64(6).
-
[show abstract]
[hide abstract]
ABSTRACT: Photonic transfer through elongated optical structures of the submicrometre section microfabricated at the surface of dielectric or semiconductor samples can be enhanced by an appropriate structuration of the local refraction index (1998 Europhys. Lett. 44 686-92). We show from computerized simulations, that both the light localization and the spectroscopic properties of such structures can be used to selectively excite, in coplanar geometry, individual molecules located in the near-field.
Nanotechnology 02/2001; 12(1):75. · 3.98 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: By combining the field-susceptibility technique with the optical Bloch equations, a general formalism is developed for the investigation of molecular photophysical phenomena triggered by nanometer scale optical fields in the presence of complex environments. This formalism illustrate the influence of the illumination regime on the fluorescence signal emitted by a single molecule in a complex environment. In the saturated case, this signal is proportional to the optical local density of states, while it is proportional to the near-field intensity in the non-saturated case.
Chemical Physics Letters.
-
[show abstract]
[hide abstract]
ABSTRACT: From numerical calculations based on Green's dyadic formalism, we show that a scanning near-field optical microscope (SNOM) working with a point-like illuminating probe delivers images that contain features directly related to the local density of photonic states (LDOS). More precisely, an unambiguous identification of the partial LDOSs (x, y or z polarized) can be made in the SNOM images when the solid angle of detection reaches 2π sr.
Chemical Physics Letters.
-
[show abstract]
[hide abstract]
ABSTRACT: We analytically and numerically analyze the fluorescence decay rate of a quantum emitter placed in the vicinity of a spherical metallic particle of mesoscopic size (i.e with dimensions comparable to the emission wavelength). We discuss the efficiency of the radiative decay rate and non–radiative coupling to the particle as well as their distance dependence. The electromagnetic coupling mechanisms between the emitter and the particle are investigated by analyzing the role of the plasmon modes and their nature (dipole, multipole or interface mode). We demonstrate that near-field coupling can be expressed in a simple form verifying the optical theorem for each particle modes.
-
[show abstract]
[hide abstract]
ABSTRACT: Molecular fluorescence decay is significantly modified when the emitting molecule is located near a plasmonic structure. When the lateral sizes of such structures are reduced to nanometer-scale cross sections, they can be used to accurately control and amplify the emission rate. In this Rapid Communication, we extend Green’s dyadic method to quantitatively investigate both radiative and nonradiative decay channels experienced by a single fluorescent molecule confined in an adjustable dielectric-metal nanogap. The technique produces data in excellent agreement with current experimental work.
Phys. Rev. B. 77(12).
