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The indirect spin–spin interaction through the field of virtual phonons polarized in the plane of incidence in a magnetic layer with slip boundaries in an unbounded nonmagnetic medium can lead to the appearance of bound states of magnon polarons in the continuous spectrum of radiative bulk Lamb magnetoacoustic modes. If a longitudinal plane bulk elastic wave is incident on this layer from outside, this mechanism ensures both the formation of magnetoacoustic Fano resonance and its collapse, as well as the implementation of the acoustic superradiance effect for a finite system of equidistant magnetic layers. The incidence of a quasiplane longitudinal wave can be accompanied by a sharp enhancement of the angular Shoch effect.

Particular cases of reflection of bulk acoustic waves from a free surface of cubic crystal, when both the plane of incidence and the crystal surface are symmetry planes, to which the polarization vectors of incident and reflected waves are parallel, have been analyzed. The conditions under which only a single bulk reflected wave (rather than two as generally) is formed at reflection are described. The accompanied reflected wave (bulk or localized) disappears, so that the reflection turns out degenerate. Either a pure reflection (the incident and reflected waves belong to the same acoustic branch) or a conversion reflection (the given waves belong to different branches) are formed.

A novel holographic grating for simultaneous coupling of power and optical beam splitting application is designed. The proposed design incorporates two identical holo-gratings separated by a distance D. A microscopic object such as micro-sphere or micro-ring is introduced in between these two gratings at a distance $$ \frac{D}{2} $$ and a Gaussian signal is allowed to pass through the first holo-grating which emerges out of the second one. With the proposed design eleven different splitting ratios could be achieved successfully by varying dimension of microscopic objects and the orientations of holo-gratings with respect to plane of incidence. For coupling applications the simulation of the proposed design shows 100% Transmission Efficiency (TE). This leads to an immense flexibility for the use of proposed model in Photonic Integrated Circuits. We demonstrate the possibility of such a multi-functional Holographic device with the aid of Finite Difference Time Domain (FDTD) simulations. To the best of our knowledge, this is the first investigation where simultaneous beam splitting and coupling applications are realized in a holographic optical element.

The problem of light scattering and absorption by a monolayer of homogeneous spherical particles at an arbitrary angle of incidence of a plane wave, which determines the phase shift between the averaged fields in the particles, has been solved. The solution is based on the quasi-crystalline approximation of the theory of multiple scattering of waves, the mean-field approximation, and the multipole expansion of the fields and the tensor Green function in terms of vector spherical wave functions. Formulas for determining the angular distribution of the incoherently scattered field intensity, the incoherent scattering, absorption, coherent transmission, and reflection coefficients have been derived. The dependences of these characteristics on the direction of illumination are illustrated using partially ordered monolayers of dielectric and semiconductor particles as an example. It is shown that: (i) under oblique illumination the angular distribution of the scattered radiation in azimuthal scattering angle for any polarization of the incident wave (except for p and s) is asymmetric relative to the plane of incidence, (ii) the maximum of the angular distribution of the radiation transmitted through the monolayer can approach its normal with increasing angle of incidence and/or concentration of particles, (iii) there exist conditions under which the bulk of the scattered radiation is concentrated in the direction opposite to the direction of the incident radiation, and (iv) the dependence of the monolayer absorption coefficient on the illumination angle has extrema whose positions and magnitudes are determined by the polarization of the incident wave.

Variable electrodynamic parameters of composite materials are determined using the methods providing simultaneous measuring of the free- space permittivity and magnetic permeability within a broad band. Thus, the problems regarding reflection of an electromagnetic wave from the boundary of a dielectric layer and modeling of the phase shift of the wave reflected from a dielectric plate become rather relevant. We report the results of studying the effect of the electrodynamic parameters of composite materials on the characteristics of the wave reflected from a dielectric plate. Analytical expressions are derived for the phase of the reflected wave when an incident plane wave is oriented at an angle to the composite plate with variable electrodynamic parameters. The matrix method is used to obtain the equations for calculating the phase shift of the reflected wave. It is shown that for incident waves with a vector of electric field lying in the plane of incidence (TM waves) and normal to it (TE waves), a jump in the phase shift by π is observed for the electric thickness of the plate multiple of the half-wavelength. A similar phase jump is observed in the case of an incident TM wave near the Brewster angle. An analysis of the frequency dependences of the phase shift, including the phase shift and amplitude drop at a corresponding frequency, as well as data on the effect of losses in the plate material on the phase shift of the reflected wave are presented. The results of studying the angular dependence of the phase shift of the reflected wave in the region of the Brewster angle can be used in solving applied problems of electrodynamics (e.g., when developing a broadband broad-band direction finding device).

OBJECTIVE Cerenkov photons have distinctive features from scintillation photons. Among them is their polarization: their electric field is always perpendicular to the direction of propagation of light and parallel to the plane of incidence. Scintillation photons are instead considered unpolarized. APPROACH This study aims at understanding and optimizing the reflectance of polarized Cerenkov photons for optical Monte Carlo simulation of scintillation detectors with Geant4/GATE. First, the Cerenkov emission spectrum and polarization were implemented in the previously developed look-up-table Davis model of crystal reflectance. Next, we modified Geant4/GATE source code to account for scintillation and Cerenkov photons LUTs simultaneously. Then, we performed optical Monte Carlo simulations in BGO using GATE to show the effect of Cerenkov features on the photons' momentum at the photodetector face, using two surface finishes, with and without reflector. MAIN RESULTS In this work, we describe the new features added to the algorithm and GATE. We showed that Cerenkov characteristics affect their probability to be reflected/refracted and thus their travel path within a material. SIGNIFICANCE We showed the importance of accounting for accurate Cerenkov photons reflectance while performing advanced optical Monte Carlo simulations.

An instrument has been developed to study surface roughness by measuring the angular distributions of scattered light. In our instrument, a beam from a He-Ne laser illuminates the surface at an angle of incidence which may be varied. The scattered li,.ght'distribution is detected by an array of 87 fiber optic sensors positioned in a semicircular yoke which can be rotated about its axis so that the scattered radiation may be sampled over an entire hemisphere. The output from the detector array is digitized, stored, and analyzed in a laboratory computer. The initial experiments have concentrated 'on measurements of stainless steel surfaces which are highly two-dimensional and which yield scattering distributions that are localized in the plane of incidence. The results are analyzed by comparing the angular scattering data with theoretical angular scattering distributions computed from digitized roughness profiles measured by a stylus instrument. The theoretical distributions are calculated by substituting the roughness profiles into the operand of an integral equation for electromagnetic scattering developed by Beckmann and Spizzichino. This approach directly tests the accuracy of the basic optical theory.

Grating-coupled excitation of surface plasmon-polariton waves guided by the interface of a metal and an anisotropic dielectric material evinces morphological effects arising from the divergence of structural anisotropy (grating) from constitutive anisotropy (dielectric material). Even if the metal is replaced by an isotropic dielectric ma- terial, the same effects are seen in the excitation of Dyakonov surface waves. The morphological effects vanish with constitutive anisotropy, as exemplified with a columnar thin film (CTF) as the dielectric material. Both p-polarized and s-polarized incident plane waves can excite the surface plasmon-polariton (SPP) waves as well as Dyakonov surface waves, provided that either the plane of incidence and/or the morphologically significant plane of the CTF do not coincide with the grating plane.

We have investigated specific features of reflection of a plane elliptically polarized electromagnetic wave that is incident from an isotropic nonabsorbing medium onto a plane-parallel layer of a hyperbolic metamaterial the optical axis of which is parallel to the interface, while the diagonal values of the dielectric permittivity are smaller than the dielectric permittivity of the isotropic medium. Depending on the angle of incidence and the angle between the plane of incidence and the optical axis of the hyperbolic metamaterial, regimes are possible in which either an ordinary wave or an extraordinary wave, or both waves decay outward from the interface, and, in the latter case, for some values of these angles, the decay may be nonexponential. For these three regimes, the reflection coefficient from a layer of an ITO/Ag nanostructure has been calculated numerically. Upon variation in the polarization of the incident wave, the energy reflection coefficient changes from minimum to maximum values, which depend on the layer thickness. As distinct from conventional anisotropic media, in all cases, the maximum value of the reflection coefficient tends to unity with increasing layer thickness. If the amplitude of an ordinary or extraordinary wave does not decrease outward from the interface boundary, the minimal reflection coefficient periodically turns to zero with increasing layer thickness due to interference. In the case in which both waves decay, with this decay being nonexponential under certain incidence conditions, the minimum reflection coefficient turns to zero at a certain layer thickness, and then tends to unity.

A theoretical method for investigating reflection of a finite-aperture plane light beam from a flat-layered structure in the Kretschmann scheme is considered. The developed theory is applied for investigating the Goos–Hanchen effect, which arises upon incidence of a linearly polarized light beam with the polarization vector lying in the plane of incidence (p-polarized beam) and which is that, upon reflection, the incident beam is divided into two close beams of the same polarization. The accuracy of sensors based on this effect is discussed.

Results are presented that have been obtained in numerical and experimental investigations of three-layer single-mode and multimode polystyrene, liquid, and liquid-crystal integrated optical waveguides. Numerical simulation results are presented and compared to the experimental data. The form of the scatter diagram from both the coordinates of the observation points and the waveguide phase slow-down factor is investigated. Characteristic experimental scatter diagrams in the plane transverse to the plane of incidence are given for TE- and TM-polarization. Calculated and experimental scatter diagrams are found to be in satisfactory agreement. Measurement of optical loss in the waveguides has allowed determining, in particular, the root-mean-square roughness height of the substrates of the polystyrene and liquid waveguides, which fairly corresponds to the known surface finish. In the liquid-crystal waveguide, the investigations have been focused on the features of the TE- and TM-mode scattering in a wide range of the phase slow-down factor variation. Complicated nonlinear processes of radiation field transformation beyond the waveguide are observed experimentally and through numerical simulation. Statistical parameters obtained for the irregularities of the investigated waveguides are presented. In addition, the root-mean-square estimates are given for spatial fluctuations of the director and compared to the average correlation radius for fluctuations of local orientation of nematic liquid crystal molecules.

CuSe-based structures are widely used in various fields of photonics and optoelectronics. It has been shown for the first time that a photocurrent depending on the direction of the wave vector and polarization of the incident radiation can be excited in thin films consisting of amorphous Se and CuSe nanocrystallites. Films on glass substrates have been obtained by the successive thermal deposition of selenium and copper in vacuum at room temperature. The photocurrent has been excited by radiation of a femtosecond laser at a wavelength of 795 nm at room temperature. It has been found that the longitudinal photocurrent measured in the direction of the plane of incidence is maximal at p-polarization and vanishes at s-polarization. The transverse pho-tocurrent perpendicular to the plane of incidence is an odd function of the polarization angle and is absent at p- and s-polarizations. In both cases, the photocurrent is an odd function of the angle of incidence of light on the film surface. The results obtained are in qualitative agreement with the theory of generation of the surface photogalvanic effect.

The diffraction of electromagnetic waves at the surface periodic structures accompanied by strong anomalous effects in different diffraction orders is considered in detail for high-contrast interfaces. We restrict discussion by the transverse magnetic polarization of the incident wave (the magnetic field is orthogonal to the plane of incidence) and the simplest geometry when the plane of incidence is orthogonal to the grating grooves. The most attention is devoted to the strong maxima and minima of the energy flux density accompanying specific grazing propagation of some diffraction order. Relation to other anomalies, both Rayleigh and the resonance ones is discussed as well.

A study on the influence of multiple reflections on the transmission coefficients of uniaxial plane–parallel plates is presented. Two representative models are analyzed: one that considers only the first transmission, and a rigorous one, taking into account the multiple reflections within the plate. Modules, phases, and the interference between p and s transmitted fields are evaluated in a wide range of angles of incidence by means of three emblematic examples that illustrate the effects of thickness, birefringence, and optical axis orientation. For simplicity, whereas the optical axis can form an arbitrary angle with the interface, it is restricted to the plane of incidence. A complete theoretical framework is provided along with general reference guidelines derived from numerical examples.

A beam of arbitrary structure is represented as a set of plane monochromatic waves using the Fourier transform. Each of the plane waves falls obliquely in an arbitrary plane of incidence, in such a way that all projections of its wave vector are not equal to zero. The reflection and transmission matrices are obtained for a plane electromagnetic wave incident from an isotropic medium onto a plane inhomogeneous anisotropic layer located on an isotropic base. The found matrices are used to calculate the reflected and transmitted beams.

The performance of solar systems depends on the effective incident solar energy on the capture surface. This factor is dependent on the geographic position, the orientation of the surface, atmospheric conditions, and other geo-climatic factors. Solar trackers, typically uni- and biaxial, are used to optimize the capture of solar radiation via movement of the plane of incidence of these devices. A reliable estimation of the energy gain of these trackers with respect to a fixed surface facilitates more accurate analyses of the feasibility, operation, and maintenance of solar ventures. In this work, a method for estimating the relative energy gain of uni- and biaxial solar trackers is developed. This approach applies to locations between the Arctic Circle and the Antarctic Circle, using geographic coordinates and the altitude of the location of interest, providing daily results throughout the year. Unlike empirical results or case studies, the proposed method applies to any location and has a low error. It can be implemented using iterative algorithms with a low computational cost and can be easily utilized by researchers and technicians in the field.

Deterministic illumination diffractive-diffusers have non-periodic short and medium scale topography. Because of the quasi-randomized locations and vertical sidewalls at phase transition boundaries, over-coating diffractive diffusers with thin film antireflection layers perturbs their function, resulting in illumination performance deviations and nonuniformities. To mitigate these effects, we added anti-reflection random nano-structures (rARSS) on the surface of three different classes of fused-silica multi-phase diffractive diffusers, using reactive-ion plasma etching. The diffusers were measured before and after the random nanostructure addition, using a polarized-laser scatterometer with a dynamic range of nine orders-of-magnitude. The bi-directional scatter distribution function (BSDF) was measured over the entire equatorial plane of incidence, to analyze the directionality of scattered light, and the impact of the rARSS on the optical performance of the diffusers. An overall Fresnel reflectivity suppression was measured in the directional illumination patterns, as well as, across the entire 180° angle-sweep. The designed deterministic illumination distribution patterns and contrast were unaffected by the presence of the rARSS.

For a given material, the bi-directional reflectance distribution function (BRDF) spatially describes how much light from any given incident direction reflects into each possible scattered direction. One common simplification in both BRDF measurement and modeling is to assume that material reflectance is isotropic throughout the scattered hemisphere with respect to the azimuthal direction. However, in reality, many materials with directionally-dependent surface characteristics, such as milled metals, are likely to exhibit anisotropic BRDFs, particularly noticeable near specular peaks. Scatter measurement devices similar to the modified Complete Angle Scatter Instrument® (CASI®) operated at the Air Force Institute of Technology (AFIT) are capable of direct specular measurements with high spatial resolution, but constrained within the plane of incidence. Anisotropic measurement techniques often sacrifice spatial resolution, particularly near specular peaks. In this work, AFIT's CASI® is augmented by installing a scientfic-grade monochrome charge-coupled device (CCD) camera on the detector arm, whose pixel array captures both in-plane and out-of-plane specular scatter measurements with high spatial resolution. Camera mounting and alignment processes are presented, including required beam attenuation for the visible red helium neon laser source used. The beam signature is measured and characterized, and the camera's effective dynamic range is extended using various exposure times. Beam signature is converted from raw digital counts to BRDF values, providing the baseline for an idealized perfectly specular material. Ultimately, this work is expected to lead towards improvements in measuring and modeling BRDFs for materials exhibiting anisotropic or out-of-plane reflectance properties for a range of radiometric remote sensing applications.

In this paper, it is shown that under the conditions of total internal reflection of plane homogeneous electromagnetic waves at the interface of a hyperbolic metamaterial and an ordinary isotropic medium, special inhomogeneous electromagnetic waves are excited in certain circumstances near the surface of the metamaterial and their amplitude changes with distance according to the non-exponential law. The existence conditions for such waves are established for the case when the optical axis is located within the interface plane and forms an angle with the plane of incidence. The energy flux and the energy density of special inhomogeneous waves in a hyperbolic metamaterial are determined.

In this paper, we present a novel configuration of an optical angle-of-incidence (AOI) sensor based on the application of a freeform mirror. The main challenge in designing this mirror was to provide a strictly linear transformation between AOI and the spatial position of the spot created on the linear detector array. Another two goals of this paper were to minimize stray light issues (improve the dynamic range) and create an intermediate focus and lateral shift in the detector position with respect to the plane of incidence. From an optical point of view, the designed mirror can thus be understood as the composition of three components: a high-numerical-aperture (NA) fully achromatic f-theta lens in one cross-section and a perfectly focusing lens, combined with a deviating prism in the second (orthogonal) cross-section. In comparison to the standard &ldquo, shade&rdquo, methods, the proposed approach allows a constant angular resolution to be maintained over the entire field of view. The mirror was designed on the basis of fundamental geometrical rules by numerically solving differential problems using an innovative scheme based on the minimization of the specific merit function. The proposed method was practically applied to design a freeform mirror for a 90&deg, /120&deg, field-of-view sensor, showing a satisfactory performance.

When the trajectory of an incident beam is oriented parallel to the grooves of a periodic grating structure the radiation beam is diffracted off-plane orthogonal to the plane of incidence. The diffraction efficiency in this condition is very high and in a grating with a sawtooth profile it can approach the reflection coefficient for a simple mirror, when the diffraction order of interest follows the direction for specular reflection at the flat part of the steps. When this concept is used in a plane grating in a monochromator for synchrotron radiation sources, the incident beam is almost always collimated in order to minimize any deterioration of the beam properties due to aberrations, which will be introduced in the diffraction process when an uncollimated beam is used. These aberrations are very severe when the groove density is constant. It will be shown that the effect of these aberrations can be corrected after the diffraction by the use of astigmatic focusing. The latter can be provided by a crossed mirror pair with different focal lengths in the corresponding orthogonal directions. Then a monochromator based on this concept can provide source size limited spectral resolution in an uncollimated incident beam. This is identical to the spectral resolution that can be provided by the same grating when operated at the same position in a collimated incident beam. The source size limited spectral resolution in this case corresponds to a high spectral resolving power of better than ΔE/E = 10 000 for photon energies around 300 eV in the soft X-ray range.

International audience; We illustrate a technique by which heterodyne-detected sum-frequency generation spectroscopy is performed at multiple angles of incidence in order to decompose components of the second-order susceptibility tensor when all beams are polarized parallel to the plane of incidence. As an illustration we study the non-vibrationally resonant gold response. We benchmark our results by comparing with measurements obtained in a polarization scheme that isolates a single element of the susceptibility tensor. Our technique is particularly valuable in the case of metal substrates, where the surface selection rule often prevents spectra from being acquired in multiple beam polarizations.

In this letter, we investigated the impact of long range surface plasmon resonance (LRSPR) on the spatial and angular shifts of left and right spin components of a p-polarization Gaussian beam reflected from a glass-fused silica-gold-fused silica interface, and deduced the formulas of these shifts. We found that the spatial and angular spin splitting of left and right spin components only occur in the direction perpendicular to the plane of incidence (out-of-plane), but not in the direction parallel to the plane of incidence (in-plane). The spatial and angular in-plane shifts of left and right spin components are the same, which are equal to those of the total reflected beam (i.e., angular and spatial Goos–Hanchen shifts). We found that all the in-plane and out-of-plane shifts can be greatly enhanced by LRSPR. The maximum angular and spatial in-plane shifts can be up to 1.060 × 10−4 rad and 249.977 μ m, respectively, which are almost equal to half of the divergence angle and beam waist of the incident Gaussian beam. The maximum spatial in-plane shift (about 20.148 μ m) is about 5 times larger than the previously reported enhanced value. We also found that the directions and magnitude of angular and spatial in-plane and out-of-plane shifts can be controlled by slightly adjusting the angle of incidence or the thickness of fused silica film or gold film under certain conditions, which may provide a new way for photon manipulation. Furthermore, our work may provide some help for precision measurement of physical and biological parameters and the development of SPR sensing technology.

The reflected field calculation from the object can be described with the set of point reflectors with the coordinates in electromagnetic wave plane of incidence corresponding to two-dimensional grid nodes with rather small-sized step. At the same time, the single scattering model which does not consider the re-reflection and point elements cross impact is used in the reflected field calculations. The rapid direct and inverse transformation algorithm is used. The numerical solution algorithms of the direct and inverse scattering problems on the object are offered. The method uses the ray representations scattering fields which are based on the Huygens-Fresnel principle. The graphic diagram of the reciprocal object positioning and the observation plane from the reflected electromagnetic field object is represented. The double reflecting Gaussian surface is graphically figured. The figures of the module and the complex amplitude electric field strength of the reflected wave from a double Gaussian surface argument are provided. To shape the surface of the unknown object the recovery shape algorithm is used, by means of reflected wave phase. This algorithm is based on finding the complex matrix elements in dependence on absolute phase, which is proportional to the appropriate point object distance.

We investigate theoretically and experimentally the beam shifts of a Gaussian beam reflected by an air-glass interface at Brewster incidence. For a linearly polarized incident beam, the reflected beam will undergo a spatial spin splitting within the plane of incidence. This spin splitting is up to 83 μm when the incident beam waist is 90 μm. Additionally, the reflected beam will be deflected along the direction perpendicular to the incident plane, i.e., undergo an angular shift. The maximum angular shift has been theoretically predicted and experimentally confirmed. Both the spatial spin splitting and angular shift can be controlled by the incident polarization state. These controllable giant beam shifts have potential applications in the design of spin-photonic devices and the optical sensing.

This study reports a crossed Czerny–Turner spectrometer with multiple mirrors to extend the inspected spectrum. A design example with two movable mirrors and a stationary planar mirror is experimentally demonstrated to offer two additional spectral bands, thereby leading to thrice the spectral range of the original Czerny–Turner spectrometer. The results indicate that the configurations to measure the three bands have almost identical parameters. The moving direction of the planar mirror and the plane of incidence are orthogonal; thus, the influence of mirror movement on the repeatability of the spectrum is minimized. In addition to the merits of cost-effectiveness and rapid inspection, the reported mechanism of mirror movement is applied to general spectrometers to extend the spectral coverage without sacrificing the resolution.

The incident angle dependences of the diffraction properties of orthogonal-circular polarization gratings (OCPGs) fabricated using a polymer liquid crystal exhibiting biaxial anisotropy have been investigated. The investigations were conducted with the plane orthogonal to the surface of the OCPGs as the plane of incidence. It was found that a specific biaxial anisotropy reduces the incident angle dependence of optically thin OCPGs against the wavelength of the incident light, and is less effective on thick OCPGs. In addition, a method also has been proposed to determine the biaxial anisotropic shape that most reduces the incident angle dependence in thin OCPGs.

Metrological analysis of triangulation laser sensors for measuring distance to mirror surfaces was performed. Theoretical and experimental studies have established that the measurement range of distance depends on the angle of incidence of the laser beam, and the main factor that affects the measurement accuracy is the rotation of the sensor in the plane of incidence. A non-contact sensor for measuring distance to liquid surfaces which provides signaling upon reaching a prescribed value is designed. An overview of triangulation measurement systems is given.

The existing polarization-insensitive filters based on two dimensional (2-D) grating are mostly under normal incidence. However, in filtering optical devices, the normal incidence regime is usually avoided because it requires the use of beam separators which yields a loss of efficiency. Herein, we present a compact method to realize polarization-independent filter under oblique incidence, which is implemented on 2-D crossed grating in the telecommunication region. Plane of incidence is set to be in xz plane and three different polarization angles (0°, 45°, and 90°) are used to demonstrate the polarization-insensitivity. Realization of the polarization-insensitivity of the 2-D filter is based on the split feature under oblique incidence, according to the analysis of the physical mechanism. The location of the polarization-independent resonance is mainly determined by the grating period along x-axis and will right shift with increasing the period. Results show that the polarization-insensitive resonances occur at 1356.9 nm, 1372.6 nm and 1398.5 nm when the grating periods along x-axis are 830 nm, 850 nm and 870 nm, respectively. Moreover, the results and methods provided herein can be applied to search for the polarization-insensitive resonances of the 2-D grating with other planes of incidence.

Possibilities of standard multiangle monochromatic ellipsometry in the determination of parameters of a uniform biaxially anisotropic layer are studied for the case of an arbitrary orientation of the two principal axes in the plane of incidence of the light beam and perpendicularity of the third axis to the plane of incidence. Using numerical simulation, it has been found that the measurement accuracy that is necessary in the determination of all the three principal components of the dielectric permittivity tensor e and tilt angle of the axes using only angular dependences of ellipsometric parameters must be no worse than 0.0001°, which is far beyond the accuracy limits provided by present-day ellipsometers. If the tilt angle is known, standard multiangle monochromatic ellipsometry provides the determination of thickness and all three principal components of the dielectric permittivity tensor. This method allows one to determine the layer thickness and tensor component for the axis perpendicular to the plane of incidence, as well as the average value of components for the axes lying in the plane of incidence without involving the data about the tilt angle of the axes. This is demonstrated by an example of experimental data for biaxially anisotropic SiO x films obtained by oblique deposition of silicon monoxide SiO evaporated in vacuum.

We report on the optical properties of silver films and nanowires grown on laser-patterned polyethyleneterephthalate (PET) foils. Polymer substrates with Laser Induced Periodic Surface Structures (LIPSS) were used as templates for vacuum evaporation of silver. Metal deposition under normal and grazing angle of incidence resulted in corrugated silver layers and nanowire gratings, respectively. The samples were studied with polarization resolved transmission spectroscopy. Angle dependent spectra were recorded by tilting the sample stepwise from 0 to 50°, with the plane of incidence parallel or perpendicular to the nanowires. The energy of the localized plasmon excited on the nanowire grating by light polarized perpendicular to the nanowire axis depends mostly on the dimension of the nanowires (width). On the other hand, transmission spectra of the thin corrugated metal layer show a strong angular dependence, owing to the propagating nature of the corresponding surface and interface plasmons.

A scheme of resonant terahertz (THz) radiation generation by non-linear beating of two lasers in hot magnetized plasma with step density profile is investigated. Beating lasers of frequency difference ω1 − ω2 ≈ ωp(~1 THz) is incident obliquely on plasma surface and exerts non-linear ponderomotive force on plasma electrons. The plasma electrons start oscillating in the plane of incidence and give rise to space charge field to maintain plasma neutrality. In turn, both ponderomotive force and space charge field excites a non-linear surface current, responsible for THz radiation generation on the reflection side. The coupling between plasma wave and electromagnetic wave present (inside the plasma as well as on reflection side) becomes stronger in the presence of the transverse DC magnetic field. THz radiation amplitude is optimized at an angle of incidence θ ~ 50–70°.

We study the negative reflection of the extraordinary wave inside a slab of an uniaxial anisotropic absorbing material placed between two isotropic materials. The optic axis is contained in the plane of incidence. We particularize for Rutile T i O 2 that possesses a high refractive index that makes it suitable for many applications. We show the existence of negative reflection in the ray and study its dependence with the orientation of the optic axis. We also compute the limiting angle for the occurrence of this phenomenon. It is found that negative reflection occurs for almost all values of the angle of incidence.

We demonstrate the fulfilment of the conservation laws with respect to fluxes of momentum, energy, spin, and the number of photons when a plane circularly polarized electromagnetic wave reflects from a receding mirror at normal incidence. The given calculations show that spin occurs to be the same natural property of a plane electromagnetic wave, as energy and momentum.

In this paper, we investigate the reflection characteristics of a novel electric–magnetic uniaxial lossy medium, characterized by extreme material properties and having optic axis in a generic direction. The novelty of the medium is specified by particular material parameters: very large transverse and very small axial components of permittivity and permeability with respect to the optic axis of the medium. To study the reflection, we consider an interface between a simple isotropic medium and the uniaxial medium defined by the complex permittivity and permeability tensors. Electromagnetic response of the medium is analyzed under different situations by considering various orientations of the plane of incidence and by arbitrarily choosing the direction of the optic axis. We emphasize the importance of direction of the optic axis and discuss its influence on electromagnetic reflection from the interface. It is noted that this novel material exhibits a very interesting property of behaving like a pe...

Conical diffraction of a grating differs from the classical type of diffraction because the incident and diffracted wave vectors are not orthogonal to the direction of the grooves, and the light is almost parallel to the grooves. Compared with a grating in the classical type of diffraction, relatively higher diffraction efficiencies will be observed in conical diffraction. And, when the incident beam is perfectly parallel to the grooves of a rectangular grating profile (laminar grating), the symmetry of the setup causes diffraction of the intensity symmetrically around the plane of incidence. A multilayer grating is a grating which is coated with multilayers and can enhance the energy transport efficiency, especially for the tender X-ray range (1-8 keV) that covers a large number of K- and L-edges of medium-Z elements, and M-edges of high-Z elements. A multilayer laminar grating used in the symmetry of conical diffraction can obtain higher efficiency and has the feasibility of the amplitude beam splitting in the tender X-ray range. In this work, using numerical simulation, a possibility of multilayer laminar grating used in the symmetry of conical diffraction for beam splitting in 4.51 keV (Ti Kα1) has been demonstrated, showing a high efficiency and good flexibility of design.

In practical applications, EM waves may propagate from air to a building or from air to water. Hence during propagation, they may encounter the interface between two different mediums. At the interface, lots of interesting phenomena occur and we can utilize these phenomena in different applications. For example, electrical engineers use the interface between air and conductor to deliver signals to a far destination. Hence it is worthwhile to study the interface behavior of EM waves. Unfortunately, the study of interface is generally not an easy task, so we break the study into three steps

We present and discuss an electromagnetic model for the description of the coherent scattering from bare soils illuminated by a radar system under arbitrary bistatic geometries. The scattering problem is solved under the Kirchhoff approximation (KA) accounting for both the sphericity of the wavefront of the incident wave and the radiation pattern of the transmitting and receiving antennas. We propose here a general formulation and solution of the scattering problem applicable to an arbitrary bistatic geometry. We discuss and demonstrate the importance of our extension for the characterization of the coherent scattering generated in bistatic radar systems, both inside and outside the plane of incidence. The model is validated against the numerical solution of the Kirchhoff integral and, in the case of the perfect plane conductor, by comparison with the image theory. The work is intended to provide a simple methodology to characterize the coherent normalized radar cross section (NRCS) of a rough surface to be used within the radar equation for extended targets, similarly to what is done for the incoherent component. It aims at enabling a local characterization of the coherent scattering in realistic conditions (e.g., in the presence of inhomogeneous and mountainous surfaces), a feature that is particularly important for practical applications, such as the modeling and understanding of the bistatic scattering generated by sources of opportunity and specifically for Global Navigation Satellite System Reflectometry (GNSS-R) related applications.

The behavior of one-dimensional waves propagating through media that are not homogeneous will be the focus of this chapter. We start with an examination of the behavior of planewaves impinging on a planar interface between two fluid media with different properties and then extend that analysis to multiple interfaces and to waves that impinge on such an interface from an angle that is not perpendicular to that surface. The extent of those boundaries separating regions with different acoustical properties will be much larger than the wavelength of the sound. Many cases to be examined here will assume that the extent of the boundary is infinite and the wave incident on such an interface will be both reflected back into the medium from which it originated and be transmitted into the second medium on the other side of the interface. This exploration concludes with consideration of wave propagation through a medium whose properties change slowly and continuously through space resulting in curved ray paths. If the variation of sound speed is linear with height or depth, then the ray paths are arcs of circles. Complicated sound speed profiles will be approximated by piecewise-linear segments that have constant sound speed gradients.

A novel deflection effect of an intense laser beam with spin angular momentum is revealed theoretically by an analytical modeling using radiation pressure and momentum balance of laser plasma interaction in the relativistic regime, as a deviation from the law of reflection. The reflected beam deflects out of the plane of incidence with a deflection angle up to several milliradians, when a non-linear polarized laser, with the intensity $I_0\sim10^{19}$W/cm$^2$ and duration around tens of femtoseconds, is obliquely incident and reflected by an overdense plasma target. This effect originates from the asymmetric radiation pressure caused by spin angular momentum of the laser photons. The dependence of the deflection angle of a Gaussian-type laser on the parameters of laser pulse and plasma foil is theoretically derived, which is also confirmed by three dimensional particle-in-cell simulations of circularly polarized laser beams with the different intensity and pulse duration.

We report excitation of the spin-polarized currents in CuSe nanocrystalline films and demonstrate that the inversion of the excitation photon helicity reverses the direction of the photocurrent propagating perpendicular to the plane of incidence. By performing measurements of the photocurrent propagating both along and perpendicular to the plane of incidence, we show that the observed spin-polarized currents originate from the circular surface photogalvanic effect (C-SPGE). In contrast to the conventional circular photogalvanic effect, which is associated with spin-orbit interaction and can be observed in gyrotropic media, the C-SPGE originates from the scattering of the spin-polarized charge carriers on the surface. We demonstrate that in CuSe films, the C-SPGE gives rise to the photon helicity sensitive photoresponse, making this material attractive for optoelectronics and spintronics applications.

Scattered light level of optical components can severely impair SNR and overall performance of optical systems for imaging and spectrometry. It is therefore necessary to directly assess its angular distribution in terms of BRDF measurements which is, due to the extreme dynamics required for high quality optical surfaces, still a challenging task. In our contribution we will present a self-built scatterometer that is based on a Czerny-Turner geometry in conjunction with a CMOS-camera detector and a single mode fiber coupled 405 nm diode laser source. Our setup is, besides simple spherical mirrors, purely based on stock-components and both, cost-effective and simple to build. Considerations on system design for high resolution and minimized instrumental signature as well as a first breadboard experimental setup will be discussed. The scatterometer utilizes the sensor’s pixels for adaptive sub-slit resolution and 2d measurements in the close vicinity of the plane of incidence. It can cover BRDF-values of up to 14 orders of magnitude and reaches resolutions well below 0.01° which allows to gain useful insights about small-angle scattering that has in the past been difficult to experimentally address. First measurements of superpolished mirrors as well as holographic and mechanically ruled diffraction gratings will be presented. Simple formulae can be used to assign rotation angles to spatial frequencies and, for smooth surfaces with negligible particulate contribution of scattering, also to PSD values and band-limited RMS roughness.

The reflection and transmission of a paraxial light beam carrying the spin and intrinsic orbital angular momenta (IOAMs) at a plane interface between two isotropic transparent media is considered. The surface transverse linear momenta (STLMs), i.e., the momenta that are localized near the interface and whose direction is perpendicular to the plane of incidence, are investigated. The IOAM-dependent and spin-dependent STLMs of the beams of homogeneous and inhomogeneous plane waves as well as the interference STLMs in the first medium are calculated. A detailed comparison of these STLMs is made. The way of experimental investigation of STLMs based on the relation between the global STLM and the transverse shift of the center of gravity of the global electromagnetic field is discussed.

We theoretically investigate non-refracted extraordinary rays where the ray does not change its direction when transmitted from a vacuum into a uniaxial crystal, even at oblique incidence. This is possible only when the optic axis is in the plane of incidence. We find that within the usual birefringence range of no≤ne≤no2, for a given angle of cut, there exits only one angle of incidence that produces a non-refracted extraordinary ray. Beyond this range, the number of solutions may be up to three. Numerical examples are given. All cases can be solved algebraically from a quartic equation.

An advanced wide-field Kerr microscopy and magnetometry approach for the investigation of magnetic anisotropy in magnetic films is demonstrated. We have analytically analysed the longitudinal Kerr contrast in a wide-field magneto-optical Kerr microscope, specifically its dependence on the light polarisation direction and the plane of incidence and verified it experimentally. While normally the sensitivity direction (i.e. the direction of maximum contrast for antiparallel domains) of the longitudinal Kerr effect is along the plane of incidence for both, p - and s-polarized light, we found a deviation of the sensitivity direction from the incidence plane for p-polarised light. Based on a multi-component Kerr imaging technique we have developed a fully automated procedure for the measurement of magnetisation reversal loops along arbitrary in-plane field directions for magnetic films with in-plane anisotropy that does not require any mechanical adjustment of the system or sample displacement. The method is applied to the investigation of the magnetic anisotropy of a sputtered iron thin film. Additionally, a sample holder was introduced, which allows for the application of mechanical stress onto magnetic films due to substrate bending, and its applicability to the stress manipulation of the anisotropy direction was demonstrated for a nickel-iron film.

Reflection and refraction of SH- wave propagation at the intersecting plane between an orthotropic media and two semi infinite dry sandy half spaces is analyzed with possible applications. The observation ensures that reflection and refraction coefficients are influenced by initial stress, dry sandy coefficient and angle of incidence. The graphs are designed to analyze the reflection and refraction of SH- wave in a layer sandwiched between two half spaces. Also, the variations of various amplitude ratio with frequency of incident wave striking at a particular angle of incidence are depicted graphically. The closest form of reflection and refraction coefficient have been explained mathematically.

This paper presents the results of the experimental investigation of the generation of nanosecond photocurrent pulses in silver–palladium (Ag/Pd) resistive films under excitation by laser pulses with a duration of 120 fs at a wavelength of 795 nm. The photocurrent was detected in the direction perpendicular to the plane of incidence of the laser beam on the film. The 20-μm-thick films under investigation were a porous polycrystalline material consisting predominantly of nanocrystallites of the palladium oxide PdO and the Ag–Pd solid solution. The direction of the photocurrent observed in the films depends on the sign of the circular polarization of the incident radiation. It was found that the observed photocurrent depends on the angle of incidence in accordance with the odd law and consists of the circular and linear contributions, which are dependent on and independent of the sign of the circular polarization, respectively. It was shown that the circular photocurrent is significantly higher than the linear photocurrent. It was established that, for both the circular and linear polarizations, the photocurrent is directly proportional to the power of the excitation radiation. For the linearly polarized laser radiation, the photocurrent depends on the polarization angle in accordance with the odd law. The regularities revealed are consistent with the mechanism of the generation of transverse photocurrent with the photon drag effect.

Made available in DSpace on 2018-11-26T17:10:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-10-01 Brazilian National Council for Scientific and Technological Development U.S. National Science Foundation The validation of remote sensing environmental estimates requires knowledge of their spatial extent and resolution. Here, we consider coherent radio reflections routinely observed in ground-based global positioning system (GPS) reflectometry. Their footprint is often conceptualized in terms of the specular point (SP) and the first Fresnel zone (FFZ). Such infinitesimal point and finite zone can be generalized into a spatially continuous sensitivity kernel (SK). The SK represents a diffraction pattern, as the importance of each surface portion depends on its scattered field contribution in power and phase. We measured the SK of a GPS radio reflection under bipath reception conditions. The SK exhibited oscillations along the plane of incidence. The envelope of oscillations peaked near the SP and persisted in its decay well beyond the FFZ. Within the FFZ, sensitivity was skewed toward the antenna. This experiment suggests the feasibility of overcoming the diffraction limit and resolving features smaller than the FFZ with the exploitation of GPS diffraction patterns. Sao Paulo State Univ, Fac Sci & Technol, BR-19060900 Sao Paulo, Brazil Univ Fed Rio Grande do Sul, Dept Geodesy, BR-91501970 Porto Alegre, RS, Brazil Univ Grenoble Alpes, ISTerre, F-38041 Grenoble, France Sao Paulo State Univ, Fac Sci & Technol, BR-19060900 Sao Paulo, Brazil Brazilian National Council for Scientific and Technological Development: 457530/2014-6 U.S. National Science Foundation: EAR-0350028 U.S. National Science Foundation: EAR-0732947