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Laser-induced formation of surface nanostructures is known for a long time. Responsible mechanisms, however, aie not completely understood. Early explanations were based on surface electromagnetic waves [1]. Alternative models were focused on self-organization of non-equilibrium surfaces via nonlinear feedback and material transport [2]. Investigations on volume structures in fused silica and glass...
The remarkably-high intrinsic optical nonlinearity of graphene can be pushed even further when the optical frequency is tuned to plasmon resonances hosted by the material when it is doped [1-4]. Atomistic simulations provide an accurate description of these phenomena, although their computational cost is prohibitive for large graphene nanostructures [3, 4]. An alternative formalism consists in relying...
Graphene plasmonics is a promising building block for high speed communication devices that takes advantage of strong confinement of the electromagnetic energy at sub-wavelength scales, tunable via charge carrier density through a gate voltage.[1] The fabrication of integrated optoelectronic devices based on graphene plasmons however is extremely challenging, and launching and conveying graphene plasmons...
We study surface plasmons on hexagonal hole arrays in gold on actively-pumped semiconductor. The observed dispersion yields the angle-dependent scattering. Lasing occurs in a radially-polarized donut beam and a hexagonal mode with mixed radial/azimuthal polarization.
Surface plasmons resonances occur when a metallic nano-particle is excited by an external electric field. Within the quasi-static limit, Ouyang and Isaacson [1] have shown that the plasmon modes are the solutions of an eigenvalue problem. This boundary element method (BEM) [2] has been extensively used to compute nano-particle plasmon resonances [3,4]. Depending on the geometry of the particle, the...
Two-level coupled systems are commonly used to describe the dynamics of a variety of physical phenomena in coupled systems, such as spin ½ systems, electron population of atomic levels, coupled waveguides and more [1]. The system is usually described by two eigenmodes — symmetric and anti-symmetric, which when excited will propagate through the system unchanged. Such two-mode dynamics was also shown...
Surface plasmon polaritons (SPPs) in plasmonic metal waveguides can excite a third-order nonlinear response [1] much akin the well-known self-phase modulation (SPM) and two-photon absorption seen in light propagating in dielectric waveguides. In metals, the nonlinearity mainly arises as a self-acting effect: after absorption of the incident light the nonlinearity arises due to hot-electron contributions...
Nonlinear optical frequency conversion in plasmonics has attracted immense research attention recently. Through various device geometries, harmonic generations of various orders have been reported. However, in these demonstrations, the near-field effect utilized has been limited to localized surface plasmons. It was not until last year that nonlinear frequency conversion utilizing propagating surface...
Plasmonic structures are promising because they strongly enhance light-matter interactions. Here we compare different one-dimensional plasmonic structures comparing them with dielectric ones in order to establish the ultimate performance of Kerr nonlinearities in these structures.
Second harmonic generation (SHG) is an important tool for the study of plasmonic nanostructures and can open up important sensing applications since the second harmonic (SH) signal has an increased sensitivity to nanostructures shape and environment in comparison with the linear scattering [1,2]. SHG from plasmonic centrosymmetric nanostructures is controlled by two main properties. First, SHG is...
The negatively charged nitrogen-vacancy (NV) color center in diamond has been widely investigated for applications spanning from quantum information processing to nanoscale sensing [1]. Central to its utility is its combination of a long-lived electronic spin state with optical initialization and readout. However, the fidelity of room-temperature NV spin readout is limited, due to the low rate of...
Semiconductor quantum dots are useful emitters in various contexts. They are, for example, a bright source of photons because of the possibility to generate multiple excitons within one quantum dot and subsequently obtain the emission of multiple photons upon each excitation. In practice, however, such multiphoton emission is often inefficient due to fast nonradiative decay channels such as Auger...
We report the formation of hybrid states of H-aggregates of organic self-assembled aromatic polycyclic molecules (PTCDI-C7) and surface plasmons polaritons (SPP). Strong coupling has already been reported in molecular systems in a number of studies [1], for the most part in J-aggregates [2]. In our system, we consider an ultra-dense layer of self organised PTCDI-C7 molecules forming H-aggregates with...
Optical vortex or orbital angular momentum (OAM) of light are a subject of active research and have been employed for novel applications such as optical manipulation, quantum information and control of cold atoms [1]. For decades, it has been discussed if OAM of light could affect the state of a bound system of charges such as an atom or a molecule, an exchange should arise between light and matter,...
Gold nanosponges are gold/air percolated nanoparticles with three dimensionally intertwined gold and air filaments of sub-20 nm diameter. The internal structure of the nanosponges, i.e. the size of the gold and air filaments can be tuned by varying the fabrication parameters [1]. Gold nanosponges exhibit multiple scattering resonances in the visible to NIR spectral range. Using dark field optical...
Great attentions are drawn to usages of localized surface plasmon enhanced (LSP) optical fields to nonlinear plasmonics. In the previous study about the nonlinear plasmonics, the multiple photons in the LSP-enhanced fields were mixed by taking advantages of the nonlinearities of the metal surfaces. Here, we tried obtaining the additional increases in the nonlinearities on the metals surfaces by using...
The ultra-sensitive real time detection and exotic manipulation of single biomolecules find its application in diverse fields of science and medicine especially in new generation integrated diagnostic assays. In this backdrop, with their very high quality factors, the whispering gallery mode (WGM) microresonators have attracted the prominence due to their ultra-sensitive label-free detection capabilities...
Here we report on promising strategies for photon management in organic optolectronic devices. Multilayered hybrid plasmonic nanostars are used to boost the performance of organic light-emitting diodes (OLEDs). We designed and synthesized silver-enhanced gold nanostars coated with a very thin silica layer (∼10 nm), so that the hot-spots at the tips of the nanostars remain easily accessible, while...
The chalcogenides represent a unique material platform, capable of providing high-index dielectric, plasmonic, ‘epsilon-near-zero’ (ENZ) or topological insulator properties when the constituent elements are combined in the right proportion. Moreover, they can exhibit reversible, non-volatile structural transitions between solid phases with vastly different electromagnetic properties. We report here...
Strong light-matter interaction leads to the appearance of new states, i.e. exciton-polaritons, with photophysical properties rather distinct from their constituents. Recent developments in fabrication techniques allow us to make metallic structures with strong electric field confinement in nanoscale mode volumes, allowing for a facile assembly of strongly coupled systems at room temperature based...
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