Dipolar and symmetrical heptamethine dyes featuring strong linear absorption in the near-infrared spectral range (700−900 nm) were prepared at a gram scale. X-ray crystallographic structure of dipolar chromophore is described revealing remarkable planarity polyenic chain due to central ring molecule. These chromophores present promising nonlinear properties telecommunication wavelengths (1400−1600 nm): (i) significant two-photon cross-sections measured using femtosecond Z-scan method, (ii)...

Aza boron-dipyrromethene dyes functionalized by extended donor-π-conjugated moieties present high potentialities for nonlinear applications in the telecommunication spectral range (1300–1500 nm). Their significant two-photon absorption cross-sections (σ2 > 600 GM) over this entire range, combined with their stability and solubility, allow transmission experiments. Detailed facts of importance to specialist readers are published as "Supporting Information". Such documents peer-reviewed, but...

Spectroscopic properties, two-photon absorption (TPA) and excited state (ESA), of two organic cyanine dyes a ruthenium based organometallic are compared in order to rationalize their similar ns-optical power limiting (OPL) efficiency the telecommunication wavelength range. The TPA contribution ns-OPL behavior is higher for both cyanines, while main process TPA-induced ESA case system, which induces broadening NIR-ESA band resulting strong spectral overlap between spectra.

We describe the linear and nonlinear optical properties of substituted aza-boron-dipyrromethene (aza-BODIPY) dyes with a focus on impact spatial position electronic nature substituents. The experimental findings are rationalized through time-dependent density functional theory calculations, pointing out crucial importance intramolecular charge transfer to achieve strong two-photon absorption in near-infrared, measured cross sections up 3300 GM at ca. 1200 nm 1110 telecommunication...

We report on the design and exploitation of a real-field laboratory demonstrator combining active polarimetric multispectral functions. Its building blocks, including multiwavelength pulsed optical parametric oscillator at emission side hyperspectral imager with capability reception side, are described. The results obtained this illustrated some examples discussed. In particular it is found that good detection performances rely joint use intensity images, these images exhibiting...

This work describes the preparation and characterization of first efficient solid-state optical limiter operating in NIR region (telecommunication wavelengths). Nonlinear absorbing chromophores (azabodipy) are incorporated into a sol–gel monolithic matrix using specifically adapted process, which preserves chemical integrity dyes solid. Efficient broadband OPL performances solid state could be observed for time between 1200 1600 nm, with maximal efficiency around 1300 nm. The properties even...

The approaches developed by Wagner (1966) and Smith (1967) for computing the shadowing properties from a one-dimensional randomly stationary surface are investigated an arbitrary uncorrelated height slope probability density function (PDF) extended to two-dimensional in monostatic bistatic configurations. Bourlier et al. (see Progress Electromagnetic Research, J. A. Kong, Ed., vol.27, p.226-87, 2000) have expressed, Brown's (1980) work , average functions, surface, whatever assumed PDF. They...

This paper deals with the calculation of scattering cross-section polarized electromagnetic plane waves from 2-D metallic and dielectric randomly rough surfaces. The cross- section object is calculated by Local Small Slope Approximation (SSA), then compared experimental data. In this paper, second order terms SSA method have been numerically implemented in to obtain accurate results for a large range slope. we consider scattered incident wave vectors arbitrary directions, materials...

This study presents the synthesis, spectroscopic and electrochemical properties of new bis- tetra-substituted azaboron-dipyrromethene (aza-BODIPY) dyes substituted by different electron donating groups connected to aza-BODIPY core through a thiophene unit. In line with theoretical calculations, experimental measurements point out positive impact group that behave as secondary donor leading an enhancement intramolecular charge transfer process in comparison previously reported dyes....

The small perturbations method has been extensively used for waves scattering by rough surfaces. standard developped Rice is difficult to apply when we consider second and third order of scattered fields as a function the surface height. Calculations can be greatly simplified with use reduced Rayleigh equations, because one unknown eliminated. We derive new set four equations amplitudes, which are applied cases conducting surface, slab where boundary surface. As in one-dimensional case,...

This paper aims at modeling bi-periodic micro-structured silicon surfaces exhibiting broadband antireflection properties in the infrared range using Rigorous Coupled-Wave Analysis (RCWA). These structures of pyramidal shape, which typical dimensions are smaller than wavelength, not Effective Medium Theory (EMT) validity domain. The influence various opto-geometrical parameters such as period, depth, shape pattern is examined. antireflective patterned then discussed photonic crystal theory...

Abstract Aza‐boron dipyrromethenes (aza‐BODIPYs) presenting a benzothiadiazole substitution on upper positions are described. The strong electron‐withdrawing effect of the moiety permits enhancement accepting strength and improves delocalization aza‐BODIPY core to attain significant degree electronic communication between lower donating groups groups. nature intramolecular charge transfer is studied both experimentally theoretically. Linear spectroscopy highlighted strongly redshifted...

In recent years, an interest in the detection of Short Wave Infra-Red (SWIR) band has grown. these wavelengths, we benefit both from properties visible and thermal infrared, offering new information a different contrast to image. defense field, this offers possibility passive active imaging, as well laser or radiation bodies above ambient temperature. The state-of-the-art III-V detectors SWIR are InGaAs photodiodes on InP substrate that limited by 1.7 μm cut-off wavelength. Super-lattice...

In his approach Voronovich [21] remarks that the unitary of scattering matrix implies a reciprocity theorem leading to following properties: R(p, pfor an horizontal translation rough boundary h(rand for vertical h(rUsing these results proposes expression matrixin case surface located between media 0 and 1.The functional Φ which depends on h has be determined.The conditions ( 31) 32), lead some properties (here it is more convenient work with Fourier transform [p, p ; r; [h]] respect variable...

We propose two distinctive designs of metamaterials demonstrating filtering functions in the visible and near infrared region. Since emissivity is related to absorption a material, these filters would then offer high infrared, low one beyond those wavelengths. Usually, such system find their applications thermo-photovoltaics field as it can well particular interest optoelectronics, especially for optical detection. Numerical analysis has been performed on common metamaterial designs:...

An optical power limiter (OPL) device can change its properties depending on the input light intensity: it is ideally transparent at low incident and presents a decrease in transmission when intensity increases. This phenomenon be used for protection of sensors. paper design functionalized aza-BODIPY chromophore, combining good nonlinear two-photon absorption exited-state short-wave infrared range (1300–1600 nm). The chromophores also show excellent thermal photochemical stabilities. Their...

This paper presents the numerical simulation and fabrication of a metasurface composed silver nanorings with split-ring gap. These nanostructures can exhibit optically-induced magnetic responses unique possibilities to control absorption at optical frequencies. The coefficient nanoring was optimized by performing parametric study Finite Difference Time Domain (FDTD) simulations. scattering cross sections are numerically calculated assess impact inner outer radii, thickness gap one nanoring,...

The problem of an electromagnetic wave scattered by a slab with two rough boundaries is solved the small-perturbation method under Rayleigh hypothesis. To obtain perturbative development, we use systematic procedure that involves integral equations called reduced equations. Then show for dielectric deposited on silver film backscattering enhancement can be produced guided waves interact surfaces.

The small slope approximation (SSA) and the Kirchhoff approach (KA) are applied to prediction of microwave sea surface backscatter for both Ku C bands various wind speeds incident angles. Numerical results obtained assuming a non-directional wavenumber spectrum compared with azimuthally averaged Cand Ku-band radar backscattering data. KA can be rigorously perfectly-conducting surface, whereas dielectric either order one (KA1) or stationary phase (SP) method used. data incidence angles...

Abstract When solving electromagnetic rough-surface scattering problems, the effect of shadowing by surface roughness often needs to be considered, especially as illumination angle approaches grazing incidence. This paper presents Ricciardi-Sato, well Wagner and Smith formulations for calculating monostatic bistatic statistical functions from a one-dimensional rough stationary surface, which are valid an uncorrelated Gaussian process with infinite length. In this paper, these extended...

In this paper, recent asymptotic backscattering models are compared for one-dimensional multiscale dielectric sea surfaces with Gaussian statistics and by considering the Elfouhaily et al. height spectrum. We focus on calculations of normalized radar cross sections (NRCS) obtained from weighted local curvature approximations (WCA LCA), recently published Elfouhaily, first- second-order small slope approximation (SSA(1) plus SSA(2) denoted as SSA), developed Voronovich. Voronovich (2002 Waves...