Spatio-temporal second-order quantum correlations of surface plasmon polaritons

We present an experimental methodology to observe spatio-temporal second-order quantum coherence of surface plasmon polaritons which are emitted by nitrogen vacancy color centers attached at the apex of an optical tip. The approach relies on leakage radiation microscopy in the Fourier space and we use this approach to test wave-particle duality for surface plasmon polaritons

Plasmonique classique et quantique sous pointe optique par microscopie en champ proche

On a metal surface, visible light can couple with surface free electrons to form a very interesting quasi-particle, the surface plasmon-polariton. The main property of this object is to be evanescent in the directions perpendicular to the surface. This feature makes the plasmon ideally suited to transport electromagnetic information in two dimensions and on a sub-wavelength scale. If it is excited by a quantum source, it retains this quantum aspect of the signal, even if millions of electrons are involved in its propagation.In this manuscript, I present the experimental and theoretical results obtained during my PhD in surface plasmonics. By combining the use of nitrogen vacancy (NV) color centers in nanodiamonds, which are single photon emitters, and of a scanning near field optical microscope (SNOM), I was able to study numerous properties of the NV center and surface plasmons, both in the classical and quantum regimes.In particular, I have performed a complete study of the internal photo-dynamics of the NV center in different excitation regimes. Moreover, I have studied the leakage radiation microscopy, a dedicated imaging mode in plasmonics , by highlighting some optical aberrations that can arise in conditions of optical index mismatch. Furthermore, I have ran spatio-temporal correlation measurements on surface plasmons excited by NV centers with a specific experimental system I implemented.Finally, I describe in the manuscript the very first studies of the interaction between plasmons and different elliptical and parabolic cavities milled in the metal. This has led to the measurements of the plasmonic local density of states.À la surface d’un métal, la lumière visible peut se coupler avec les électrons libres pour engendrer une quasi-particule particulièrement intéressante, le plasmon-polariton de surface. Cet objet a pour propriété d’être évanescent dans les directions perpendiculaires à la surface, ce qui en fait un support idéal pour transporter l’information lumineuse à deux dimensions, et sur des échelles sub-longueur d’onde. S’il est excité par une source quantique, il conserve cet aspect quantique du signal, même si des millions d’électrons sont impliqués dans sa propagation.Dans ce manuscrit, je présente les résultats expérimentaux et théoriques obtenus en plasmonique de surface durant mon doctorat. En associant l’utilisation de centres colorés azote-lacune (NV) dans les nanodiamants, qui sont des émetteurs de photons uniques, et d’un microscope optique en champ proche (SNOM), j’ai pu étudier de nombreuses propriétés du centre NV et des plasmons de surface dans les domaines classique et quantique.Notamment, j’ai réalisé une étude complète de la photo-dynamique interne du centre NV, dans différents régimes d’excitation. De plus, j’ai étudié le mode d’imagerie des plasmons de surface qu’est la microscopie à fuite radiative, en mettant en lumière certaines aberrations optiques pouvant survenir dans des conditions de désaccord d’indices optiques. J’ai ensuite effectué des mesures de corrélations spatio-temporelles de plasmons de surface excités par des centres NV, grâce à un système expérimental spécifique que j’ai mis en œuvre.Enfin, je décris dans ce manuscrit les toutes premières études de l’interaction des plasmons avec différentes cavités elliptiques et paraboliques gravées dans le métal, qui ont mené notamment à des mesures de densité locales d’états (LDOS) plasmonique

Directional and singular surface plasmon generation in chiral and achiral nanostructures demonstrated by Leakage Radiation Microscopy

In this paper, we describe the implementation of leakage radiation microscopy (LRM) to probe the chirality of plasmonic nanostructures. We demonstrate experimentally spin-driven directional coupling as well as vortex generation of surface plasmon polaritons (SPPs) by nanostructures built with T-shaped and $\Lambda$- shaped apertures. Using this far-field method, quantitative inspections, including directivity and extinction ratio measurements, are achieved via polarization analysis in both image and Fourier planes. To support our experimental findings, we develop an analytical model based on a multidipolar representation of $\Lambda$- and T-shaped aperture plasmonic coupler allowing a theoretical explanation of both directionality and singular SPP formation. Furthermore, the roles of symmetry breaking and phases are emphasized in this work. This quantitative characterization of spin-orbit interactions paves the way for developing new directional couplers for subwavelength routing

Experimental demonstration of random walk by probability chaos using single photons

In our former work (Sci. Rep. 4: 6039, 2014), we theoretically and numerically demonstrated that chaotic oscillation can be induced in a nanoscale system consisting of quantum dots between which energy transfer occurs via optical near-field interactions. Furthermore, in addition to the nanoscale implementation of oscillators, it is intriguing that the chaotic behavior is associated with probability derived via a density matrix formalism. Indeed, in our previous work (Sci. Rep. 6: 38634, 2016) we examined such oscillating probabilities via diffusivity analysis by constructing random walkers driven by chaotically driven bias. In this study, we experimentally implemented the concept of probability chaos using a single-photon source that was chaotically modulated by an external electro-optical modulator that directly yielded random walkers via single-photon observations after a polarization beam splitter. An evident signature was observed in the resulting ensemble average of the time-averaged mean square displacement. Although the experiment involved a scaled-up, proof-of-concept model of a genuine nanoscale oscillator, the experimental observations clearly validate the concept of oscillating probability, paving the way toward future ideal nanoscale systems

Photophysics of single nitrogen-vacancy centers in diamond nanocrystals

International audienceA study of the photophysical properties of nitrogen-vacancy (NV) color centers in diamond nanocrystals of size 50 nm or below is carried out by means of second-order time-intensity photon correlation and cross-correlation measurements as a function of the excitation power for both pure charge states, neutral and negatively charged, as well as for the photochromic state, where the center switches between both states at any power. A dedicated three-level model implying a shelving level is developed to extract the relevant photophysical parameters coupling all three levels. Our analysis confirms the very existence of the shelving level for the neutral NV center. It is found that it plays a negligible role on the photophysics of this center, whereas it is responsible for an increasing photon bunching behavior of the negative NV center with increasing power. From the photophysical parameters, we infer a quantum efficiency for both centers, showing that it remains close to unity for the neutral center over the entire power range, whereas it drops with increasing power from near unity to approximately 0.5 for the negative center. The photophysics of the photochromic center reveals a rich phenomenology that is to a large extent dominated by that of the negative state, in agreement with the excess charge release of the negative center being much slower than the photon emission process

Plasmonique classique et quantique sous pointe optique par microscopie en champ proche

On a metal surface, visible light can couple with surface free electrons to form a very interesting quasi-particle, the surface plasmon-polariton. The main property of this object is to be evanescent in the directions perpendicular to the surface. This feature makes the plasmon ideally suited to transport electromagnetic information in two dimensions and on a sub-wavelength scale. If it is excited by a quantum source, it retains this quantum aspect of the signal, even if millions of electrons are involved in its propagation.In this manuscript, I present the experimental and theoretical results obtained during my PhD in surface plasmonics. By combining the use of nitrogen vacancy (NV) color centers in nanodiamonds, which are single photon emitters, and of a scanning near field optical microscope (SNOM), I was able to study numerous properties of the NV center and surface plasmons, both in the classical and quantum regimes.In particular, I have performed a complete study of the internal photo-dynamics of the NV center in different excitation regimes. Moreover, I have studied the leakage radiation microscopy, a dedicated imaging mode in plasmonics , by highlighting some optical aberrations that can arise in conditions of optical index mismatch. Furthermore, I have ran spatio-temporal correlation measurements on surface plasmons excited by NV centers with a specific experimental system I implemented.Finally, I describe in the manuscript the very first studies of the interaction between plasmons and different elliptical and parabolic cavities milled in the metal. This has led to the measurements of the plasmonic local density of states.À la surface d’un métal, la lumière visible peut se coupler avec les électrons libres pour engendrer une quasi-particule particulièrement intéressante, le plasmon-polariton de surface. Cet objet a pour propriété d’être évanescent dans les directions perpendiculaires à la surface, ce qui en fait un support idéal pour transporter l’information lumineuse à deux dimensions, et sur des échelles sub-longueur d’onde. S’il est excité par une source quantique, il conserve cet aspect quantique du signal, même si des millions d’électrons sont impliqués dans sa propagation.Dans ce manuscrit, je présente les résultats expérimentaux et théoriques obtenus en plasmonique de surface durant mon doctorat. En associant l’utilisation de centres colorés azote-lacune (NV) dans les nanodiamants, qui sont des émetteurs de photons uniques, et d’un microscope optique en champ proche (SNOM), j’ai pu étudier de nombreuses propriétés du centre NV et des plasmons de surface dans les domaines classique et quantique.Notamment, j’ai réalisé une étude complète de la photo-dynamique interne du centre NV, dans différents régimes d’excitation. De plus, j’ai étudié le mode d’imagerie des plasmons de surface qu’est la microscopie à fuite radiative, en mettant en lumière certaines aberrations optiques pouvant survenir dans des conditions de désaccord d’indices optiques. J’ai ensuite effectué des mesures de corrélations spatio-temporelles de plasmons de surface excités par des centres NV, grâce à un système expérimental spécifique que j’ai mis en œuvre.Enfin, je décris dans ce manuscrit les toutes premières études de l’interaction des plasmons avec différentes cavités elliptiques et paraboliques gravées dans le métal, qui ont mené notamment à des mesures de densité locales d’états (LDOS) plasmonique

Classical and quantum plasmonics by optical near field microscopy

À la surface d’un métal, la lumière visible peut se coupler avec les électrons libres pour engendrer une quasi-particule particulièrement intéressante, le plasmon-polariton de surface. Cet objet a pour propriété d’être évanescent dans les directions perpendiculaires à la surface, ce qui en fait un support idéal pour transporter l’information lumineuse à deux dimensions, et sur des échelles sub-longueur d’onde. S’il est excité par une source quantique, il conserve cet aspect quantique du signal, même si des millions d’électrons sont impliqués dans sa propagation.Dans ce manuscrit, je présente les résultats expérimentaux et théoriques obtenus en plasmonique de surface durant mon doctorat. En associant l’utilisation de centres colorés azote-lacune (NV) dans les nanodiamants, qui sont des émetteurs de photons uniques, et d’un microscope optique en champ proche (SNOM), j’ai pu étudier de nombreuses propriétés du centre NV et des plasmons de surface dans les domaines classique et quantique.Notamment, j’ai réalisé une étude complète de la photo-dynamique interne du centre NV, dans différents régimes d’excitation. De plus, j’ai étudié le mode d’imagerie des plasmons de surface qu’est la microscopie à fuite radiative, en mettant en lumière certaines aberrations optiques pouvant survenir dans des conditions de désaccord d’indices optiques. J’ai ensuite effectué des mesures de corrélations spatio-temporelles de plasmons de surface excités par des centres NV, grâce à un système expérimental spécifique que j’ai mis en œuvre.Enfin, je décris dans ce manuscrit les toutes premières études de l’interaction des plasmons avec différentes cavités elliptiques et paraboliques gravées dans le métal, qui ont mené notamment à des mesures de densité locales d’états (LDOS) plasmonique.On a metal surface, visible light can couple with surface free electrons to form a very interesting quasi-particle, the surface plasmon-polariton. The main property of this object is to be evanescent in the directions perpendicular to the surface. This feature makes the plasmon ideally suited to transport electromagnetic information in two dimensions and on a sub-wavelength scale. If it is excited by a quantum source, it retains this quantum aspect of the signal, even if millions of electrons are involved in its propagation.In this manuscript, I present the experimental and theoretical results obtained during my PhD in surface plasmonics. By combining the use of nitrogen vacancy (NV) color centers in nanodiamonds, which are single photon emitters, and of a scanning near field optical microscope (SNOM), I was able to study numerous properties of the NV center and surface plasmons, both in the classical and quantum regimes.In particular, I have performed a complete study of the internal photo-dynamics of the NV center in different excitation regimes. Moreover, I have studied the leakage radiation microscopy, a dedicated imaging mode in plasmonics , by highlighting some optical aberrations that can arise in conditions of optical index mismatch. Furthermore, I have ran spatio-temporal correlation measurements on surface plasmons excited by NV centers with a specific experimental system I implemented.Finally, I describe in the manuscript the very first studies of the interaction between plasmons and different elliptical and parabolic cavities milled in the metal. This has led to the measurements of the plasmonic local density of states

Single Photon in Hierarchical Architecture for Physical Decision Making: Photon Intelligence

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Directional and Singular Surface Plasmon Generation in Chiral and Achiral Nanostructures Demonstrated by Leakage Radiation Microscopy

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