The success of symbiotic reef-building corals is largely determined by the efficiency with which they collect solar energy. Using thin coral laminae from Caribbean scleractinian Porites branneri, we characterize absorption spectra intact surfaces. Comparisons a broad range photosynthetic pigment densities, collected during natural bleaching event, indicate that are capable collecting more than 85% radiation one order magnitude less density terrestrial leaves. Measurements light-absorption as...

An experimental investigation of light scattering from random rough surfaces is described. The surfaces, whose height fluctuations approximately follow Gaussian statistics, are fabricated in photoresist with a metal overcoating. When the lateral correlation length larger than wavelength and surface slopes mild, measurements diffuse found to agree Beckmann theory, as long angle incidence not too large. For other that have stronger slopes, depolarization enhanced backscattering may be observed...

We report the implementation of a one-dimensional random laser based on an Er/Ge co-doped single-mode fiber with randomly spaced Bragg gratings. The grating array forms complex cavity high quality factor resonances in range gain wavelengths centered around 1535.5 nm. reflection spectra and emission are investigated for different numbers experimental results compared qualitatively numerical simulations light propagation arrays transfer matrix method. system is pumped at 980 nm experimentally...

Multiple scattering of light on coral skeleton enhances absorption efficiency symbionts and plays a key role in the regulation their internal diffuse field. To understand dependence this enhancement meso- macrostructure, we analysed abilities naked skeletons for 74 Indo-Pacific species. Sensitive morphotypes to thermal stress, flat-extraplanate branching corals, showed most efficient structures, while massive-robust species were less efficient. The lowest light-enhancing found primitive...

We study the scattering of a p-polarized beam incident onto random grating whose grooves are perpendicular to plane incidence. The scattered field is expressed in terms total magnetic and its normal derivative on surface grating. integral equations satisfied by these functions solved numerically for each several hundred realizations profile possessing Gaussian spectrum. diffuse component differential reflection coefficient averaged over displays well-defined peak retroreflection direction...

We present an experimental and numerical study of the effects multiple scattering on optical properties reef-building corals. For this, we propose a simplified model coral describe in some detail methods for characterizing skeleton layer containing symbiotic algae. The is used to absorption light by tissue microalgae means Monte Carlo simulations. results show that, through scattering, homogenizes enhances environment which symbionts live. also that illustrate modification internal when...

Fano resonances in plasmonics have received widespread attention for their distinctly narrow asymmetric line shapes. A variety of configurations been considered, either requiring complex metallic nanostructures or being extremely faint if originated simple single nanoparticles. Here we report on the emergence high-contrast, strongly shapes light scattered from semiconductor nanorods. Numerical calculations are carried out scattering cross sections finite semiconducting nanorods, with...

The enhanced backscattering of p-polarized light from a small-rms-height, small-rms-slope, one-dimensional, random metal surface was first predicted on the basis an infinite-order perturbation calculation that used techniques many-body theory and concepts weak localization theory. We present elementary contribution to mean differential reflection coefficient incoherent component scattered is based two nonzero terms in expansion this function powers surface-profile function. show approach not...

Recently, rigorous numerical techniques for treating light scattering problems with one-dimensional rough surfaces have been developed. In their usual formulation, these are based on the solution of two coupled integral equations and applicable only to whose profiles can be described by single-valued functions a coordinate in mean plane surface. this paper we extend applicability equation method multivalued profiles. A procedure finding parametric description given profile is described,...

We present a method for designing non-absorbing optical diffusers that, when illuminated by converging beam, produce specified intensity distribution along the axis. To evaluate performance of in imaging systems we calculate three-dimensional mean neighborhood focus. find that can be used as depth-of-focus extenders. also propose and implement fabricating designed on photoresist-coated plates some experimental results obtained with fabricated diffusers.

In the present study, poly(ethylene glycol)-b-poly(N,N-diethylaminoethyl methacrylate) (PEG-b-PDEAEM) amphiphilic block copolymers were synthetized by reversible addition-fragmentation chain transfer (RAFT) polymerization using two different macro agents containing PEG of 2000 and 5000 g/mol varying length PDEAEM segment. From obtained copolymers, polymersome type nanometric aggregates techniques. By direct dispersion, particle diameters around 200 nm obtained, while solvent exchange THF...

A numerical technique for studying the generation of second-harmonic radiation in interaction light with two-dimensional particles arbitrary shape is described. The medium which are composed assumed to be homogeneous and isotropic. For special case cylindrical results compared obtained a Mie-type theory. then illustrated through calculations various shapes by use free-electron model nonlinear polarization. Among other things, we have found that, when symmetrical particle illuminated along...

Cancer is the second leading cause of death worldwide. To combat this disease, novel and specialized therapeutic systems are urgently needed. This first study to explore a system that combines shark variable domain (Fv) new antigen receptor (VNAR) antibodies (hereinafter VNARs), PEGylated nanogels (pH-sensitive poly( N , -diethylaminoethyl methacrylate, PDEAEM), anticancer drug 5-fluorouracil (5-FU) its potential applications in colon cancer therapies. Nanogels were functionalized scalable...

We compare a recently developed coherent-scattering model for the reflectance of light from turbid colloidal suspension particles with experimental measurements. The data were obtained in an internal reflection configuration around critical angle using glass prism contact monodisperse latex particles, and polydisperse TiO2 particles. First, we review coherent scattering extend it to case suspensions configuration. is then compared results assuming that system can be treated as homogeneous...

Abstract We present calculations of the efficiency excitation surface plasmon‐polaritons (SPPs) with structures illuminated by focussed beams. First, it is shown that low reflectivity observed broad highly directional beams and periodic gratings does not necessarily imply an efficient coupling to SPPs. then consider through features like steps, grooves angled calculate maps for these as functions parameters define them. Finally, we explore possibilities improving using consisting a small...

Recent experimental results of West and O'Donnell [ J. Opt. Soc. Am. A12, 390 ( 1995)] for the enhanced backscattering p-polarized light from weakly rough, one-dimensional, random gold surfaces are compared with predictions two perturbative calculations such scattering. The were fabricated to possess power spectra that nonzero in only a narrow range wave numbers about number surface plasmon polariton supported by them at frequency incident light. As consequence, is due coherent interference...

The reflectivity of p- and s-polarized light incident upon a one-dimensional, randomly rough, dielectric surface is calculated for several angles incidence, when the plane incidence normal to generators surface, by second-order small-amplitude perturbation theory, self-energy phase theory. wavelength λ = 0.6328 μm, constant scattering medium ∊ 2.25. roughness characterized rms height δ transverse correlation length a. From comparison results these approximate calculations with those obtained...

We propose a method of designing two-dimensional random surfaces that scatter light uniformly within specified range angles and produce no scattering outside range. The is first tested by means computer simulations. Then procedure for fabricating such structures on photoresist described, light-scattering measurements with the fabricated samples are presented. results validate design show fabrication feasible.

We study the generation of second-harmonic radiation in interaction light with an infinite cylinder illuminated perpendicular to its axis by s- or p-polarized monochromatic electromagnetic wave. With assumption a homogeneous and isotropic medium, we derive analytical expressions for field radiated cylinder. The theoretical results are illustrated through calculations total scattered power angular distribution employment free-electron model linear nonlinear susceptibilities. scattering cross...

By means of rigorous numerical simulation calculations based on the Green's theorem integral equation formulation, we study near electromagnetic field in vicinity very rough, one-dimensional self-affine fractal surfaces Ag, Au, and Cu (for both vacuum water propagating media) illuminated by a p-polarized field. Strongly localized enhanced optical excitations (hot spots) are found, with electric intensity enhancements close to 4 orders magnitude widths below tenth incoming wavelength. These...

We study, theoretically and experimentally, disorder-induced resonances in randomly layered samples develop an algorithm for the detection characterization of effective cavities that give rise to these resonances. This enables us find eigenfrequencies pinpoint locations resonant appear individual realizations random arbitrary distributions widths refractive indices layers. Each cavity is formed a region whose size few localization lengths. Its eigenfrequency independent location inside...