The so-called PT symmetric devices, which feature ε((-x)) = ε((x))* associated with parity-time symmetry, incorporate both gain and loss can present a singular eigenvalue behaviour around critical transition point. scheme, typically based on co-directional coupled waveguides, is here transposed to the case of variable one arm fixed losses other arm. In this configuration, scheme exploits full potential plasmonics by making beneficial use their attain regime that makes switching possible much...

We show that interfering surface plasmon polaritons can be excited with a focused laser beam at normal incidence to plane metal film. No protrusions or holes are needed in this excitation scheme. Depending on the axial position of focus, intensity distribution is either dominated by interferences between counterpropagating plasmons two-lobe pattern characteristic localized excitation. Our experiments accurately explained use angular spectrum representation and provide simple means for...

Coupling plasmonics and silicon photonics is the best way to bridge size gap between macroscopic optics nanodevices in general especially nanoelectronic devices. We report on realization of key blocks for future plasmonic planar integrated optics, nano-optical couplers, nanoslot waveguides that are compatible both with CMOS microelectronics. Copper-based devices provide very efficient optical coupling, unexpectedly low propagation losses a broadband sub-50 nm confinement. The fabrication...

We report on the fabrication of monolithic omnidirectional mirrors based one-dimensional photonic crystals. The are comprised chirped and unchirped multiple layers microporous silicon. Porosities have been chosen to achieve an optimal low refractive index nL∼1.5 a high nH∼2.55. Unchirped structures, centered in near-infrared, exhibit reflection band 100 nm, agreement with calculated structure. Chirped structures enlarged stop (340 nm). Given possibility easily tailoring optical thickness...

We present a rigorous analysis of the thermal conductivity bulk silicon (Si) and Si nanowires (Si NWs) which takes into account exact physical nature various acoustic optical phonon mechanisms. Following Callaway solution for Boltzmann equation, where resistive nonresistive mechanisms are discriminated, we derived formalism lattice that incidence angles. The scattering processes represented by frequency-dependent relaxation time. In addition to commonly considered three-phonon processes,...

We present near-field measurements of transverse plasmonic wave propagation in a chain gold elliptical nanocylinders fed by silicon refractive waveguide at optical telecommunication wavelengths. Eigenmode amplitude and phase imaging apertureless scanning microscopy allows us to measure the local out-of-plane electric field components reveal exact nature excited localized surface plasmon resonances. Furthermore, coupling mechanism between subsequent metal nanoparticles along is experimentally...

An inherent problem to the study of waveguides with strong propagation losses by Scattering-type Scanning Near field Optical Microscopy is coherent optical background which disrupts strongly weak detected near-field signal. We present a technique heterodyne detection allowing us overcome this difficulty while amplifying near As illustrated in case highly confined SOI structure, technique, besides amplitude, provides local phase variation guided field. The knowledge complex cartography leads...

For their capability to localize and redirect electromagnetic field, metal nanoparticles have been recently viewed as efficient nanoantenna operating in the optical regime. In this article, we experimentally investigated responses of coupled gold antenna pairs measured critical parameters defining characteristics: resonant frequencies bandwidths, detuning gains, radiation patterns.

Novel plasmonic structures are on the rise, with applications varying from sensing and spectroscopy to solar cells biological therapies. In this work, we introduce a metasurface very rich dispersion spectrum, measured both experimentally numerically. It shows tunable absorption that depends folding angle periodicity. A detailed numerical analysis identifies presence of quasi-omnidirectional absorption. This broad directional mode matches Fabry–Perot resonance surface plasmon polariton along...

We propose a homemade sample-holder unit used for nanopositionning in two dimensions with millimeter traveling range. For each displacement axis, the system includes long range stage and piezoelectric actuator accurate positioning. Specific electronics is integrated according to metrological considerations, enhancing repeatability performances. The aim of this work demonstrate that near-field microscopy at scale chip possible. we chose characterize highly optical structures. purpose, sample...

Abstract We report on the realization of functional infrared light concentrators based a thick layer air-polymer metamaterial with controlled pore size gradients. The design features an optimum gradient index profile leading to focusing in Fresnel zone structures for two selected operating wavelength domains near 5.6 and 10.4 μm. which consists polymer containing air holes diameters ranging from λ/20 λ/8 is made using 3D lithography technique two-photon polymerization homemade photopolymer....

Smartphone camera based gold nanoparticle colorimetry (SCB-AuNP colorimetry) has shown good potential for point-of-care applications.

We present a near field optical study of plasmonic gap waveguide vertically integrated on silicon. The experimental is based scanning microscope configured in perturbation mode. This operation mode described and modeled to give physical insight into the measured signal. A high spatial resolution allows for characteristics modes, such as distributions, effective indices, direction propagation, coupling between perpendicularly polarized be imaged analyzed with accuracy. work supported by...

In this work, we designed structures based on copper nanosubstrate with graphene and two-dimensional transition metal dichalcogenides (TMDC) in order to achieve an ultrasensitive surface plasmon resonance biosensor. This system contains seven components: SF11 triangular prism, BK-7 glass, Chromium (Cr) adhesion layer, thin film, layers of one the types dichalcogenides: MoS2, MoSe2, WS2 or WSe2 (defined as MX2), graphene, sensing layer biomolecular analyte. Copper was chosen a plasmonic...

We investigate in detail the interferometric nature of signal delivered by an apertureless scanning near-field optical microscope (SNOM). This is first brought to fore images integrated waveguide. The detection process evanescent wave generated total internal reflection then studied both lateral scans and as a function tip-to-sample distance. study permits interpretation fringe patterns appearing SNOM provides important information about signal. In particular, experimental data simple...

We study the optical coupling between a gold nanowire and silver ion-exchanged waveguide, with special emphasis on antenna radiation pattern. measure patterns of waveguide-coupled nanowires height 70 nm width 50 or 150 in 450-700 spectral range for TE TM polarizations. perform systematic theoretical wavelength, polarization, size, material dependences properties also give some elements concerning absorption near-field. Experiments calculations show localized plasmon resonance polarization...

In this paper, we present experimental evidence on the change of phonon spectrum and vibrational properties a bulk material through hybridization mechanisms. The in finite is strongly affected by presence free surfaces, which addition contribution from an essentially two-dimensional crystal. can hence be altered mechanism between confined modes nanostructures introduced surface underlying modes. We measured heat capacities bare surface-structured silicon substrates originating same wafer....

The use of laser optical feedback Imaging (LOFI) for scattering-type scanning near-field microscopy (sSNOM) is proposed and investigated. We implement this sensitive imaging method by combining a sSNOM with heterodyne interferometry the dynamic properties B class source which here used both as detector. Compared previous near field experiments, detection scheme provides an amplification that several orders magnitude higher, while keeping low noise phase-sensitive detection. Successful...

Abstract Near infrared (NIR) activable photopolymers suitable for versatile fabrication of micro‐optical elements were developed. The first main objective this article is to show that these new can be used microfabrication and investigate the parameters governing process. impact photonic, physico‐chemical, chemical discussed. High quality microstructures with a good control over their size shape are demonstrated. second practical examples microlenses waveguides implemented on single core...

This report presents the Apertureless Scanning Optical Near-Field Microscope as a powerful tool for characterization of modern optoelectronic and photonic components with sub-wavelength resolution. We present an overview results we obtained in our laboratory over past few years. By significant examples, it is shown that this specific probe microscopy allows situ local quantitative study semiconductor lasers operation, integrated optical waveguides produced by ion exchange (single channel or...

We report on NIR efficient end-coupling in single-mode silicon insulator waveguides. Efficient coupling has been achieved using Polymer-Tipped Optical Fibers (PTOF) of adaptable radius curvature (ROC). When compared with commercial micro lenses, systematic studies as a function PTOF ROC, lead for subwavelength to factor enhancement high 2.5. This experimental behavior is clearly corroborated by radial FDTD simulations and an absolute efficiency about 50% also estimated.

We report on the real-space observation of resonant frequency splitting in a high-Q waveguide-coupled silicon-on-insulator microdisk resonator. Phase sensitive near-field analysis reveals stationary nature two states, and spectral investigations clearly show their orthogonality. These measurements emphasize role coupling waveguide this phenomenon. The symmetry whispering gallery modes is observed found to follow axial as it has been reported by earlier theoretical predictions.