Polarization incident

IRRAS Infrared reflection- Grazing-incidence polarized Enhanced sensitivity... 

Fig. 3—Measurement of surface by HDI surface reflectance analyzer. In electromagnetic radiation (light), the polarization direction is defined as the direction of the electric field vector. The incident polarization of the light can be controlled. The instrument uses a variety of detectors to analyze the reflected polarization state of the light. (U.S. Patent 6,134,011). (a) Plane of the disk The SRA uses a fixed 60 degree (from the surface normal) angle of incidence. The plane of incidence is the same as the paper plane (b) Pit on a surface detected by reflected light channels of HDI instrument (c) Scratches on disk surface measured by HDI surface reflectance analyzer (d) Particles on the surface of disk detected by reflected light (black spot) and by scattered light (white spot) [8].

Enhanced electric-field distribution is illustrated schematically in Figure 3.8, based on reported electromagnetic simulations, for a dimer of a noble metal spherical nanoparticle. The optical field enhancement at the gap site occurs only when the incident polarization is parallel to the interparticle axis of the dimer. 

Figure 3.9 Near-field two-photon excitation images of gold nanosphere dimers, (a) Topography. Scale bar 500 nm. (b) and (c) Two-photon excitation images. The excitation wavelength is 780 nm. Incident polarization directions are indicated by arrows. The approximate positions ofthe particles are indicated by circles. (Reproduced with permission from The Japan Society of Applied Physics [12]).

Fig. 5.3. Top panel Polarization-dependent supercontinuum spectra obtained in sapphire. The corresponding variation in the diameter of the white light central spot as a function of incident polarization angle is shown in the lower panel...

Optical activity comes from the different refractions of right and left circularly polarized light by chiral molecules. The difference in refractive indices in a dissymmetric medium corresponds to the slowing down of one beam in relation to the other. This can cause a rotation of the plane of polarization or optical rotation. The value of specific rotation varies with wavelength of the incident polarized light. This is called optical rotatory dispersion (ORD). 

The factor 1(0) in Eq. (7.2) is a function of 8 and the polarization of the incident light these features are discussed shortly. However, we first examine the remarkable amplitude, polarization, and phase behaviors of the electric fields [from which 1(0) is derived] and the magnetic fields of the TIR evanescent wave. The field components are listed below, with incident electric field amplitudes Aps and phase factors relative to those of the incident E field s phase at z = 0. (The coordinate system is chosen such that the x-z plane is the plane of incidence. Incident polarizations p and s are parallel and perpendicular to the plane of incidence, respectively.)... 

The collected fluorescence 3F [from Eq. (7.39)] clearly depends on the orientation distribution of the dipoles and the incident polarization through the dependences on 0 and E. We will assume a special but common case here randomly oriented dipoles with a z-dependent concentration near the surface, excited by a p-polarized evanescent wave. 

E of the incident polarized X-ray relative to the axis of the a and n orbitals. This, coupled with the fact that sharp core level excitations for elements C, N, O, and F occur in the soft X-ray spectral region, makes NEXAFS an ideal technique for probing molecular orientations of organic molecules. 

Fig. 32 Dependence of cosine of A and tangent of where A and are ellipsometric angles related to the change of amplitude and phase shift of the incident polarized light, on the wavelength of the incident polarized light collected from PDMAEMA- -PAA brushes immersed in solutions of a constant ionic strength 0.001 M) and pH ranging from 3.52 to 9.50. The data in figures a and b (c and d) have been collected at the position 1 (4). For clarity the data for cos(A) and tan(V ) collected at pH > 3.53 were shifted vertically by - 0.2 relative to each previous set...

Figure 13.5 Potential modulated reflectance spectrum of p-aminonitrobenzene (PANB) on platinum (solution phase 0.5 mM Na2S04 + 0.05 mM PANB). Applied dc 0.44 V vs. SHE. Modulation amplitude 50 mV. Modulation frequency 33 Hz. Incidence angle 65°. 11 signifies incident polarization parallel to incident plane and perpendicular to electrode surface. J signifies incident polarization perpendicular to incident plane (hence parallel to electrode surface). [From Ref. 50.]...

The absorption spectrum at 0° has a maximum at 600 nm. Upon rotation of the direction of the incident polarized light by as much as 90°, the absorption intensity decreases. The anisotropy of the absorption spectra reflects the regular orientation of the photogenerated closed-ring isomers and indicates that the photochromic reaction occurred in the single-crystalline phase. The blue color disappeared by irradiation with visible light a > 480 nm). Anthracene-substituted derivatives also showed photochromic properties (01JPC(A)1741). 

Au nanorods are especially appealing as TPL probes due to their high quality factors at NIR wavelengths and their sensitivity to incident polarization, which can provide additional orientational information.217,225 The TPL intensities of Au nanorods have been shown to have a cos4 relation with respect to the polarization of incident light, and are at a maximum when aligned with their longitudinal axes (Fig. 10.10). The two-photon absorption cross-section of individual Au... 

Even in situations in which the molecules of interest are randomly oriented (e.g. in solution) the orientational distribution of emitting molecules may not be isotropic, due to the fact that the incident (excitation) beam photoselects molecules based upon the relative orientation of the absorption transition dipoles, p abs> with respect to the incident polarization vector, if [7,9,10]. The probability of absorption is proportional to I jfabs if I thus, for example, molecules oriented such that if... 

The electronic properties of organic conductors are discussed by physicists in terms of band structure and Fermi surface. The shape of the band structure is defined by the dispersion energy and characterizes the electronic properties of the material (semiconductor, semimetals, metals, etc.) the Fermi surface is the limit between empty and occupied electronic states, and its shape (open, closed, nested, etc.) characterizes the dimensionality of the electron gas. From band dispersion and filling one can easily deduce whether the studied material is a metal, a semiconductor, or an insulator (occurrence of a gap at the Fermi energy). The intra- and interchain band-widths can be estimated, for example, from normal-incidence polarized reflectance, and the densities of state at the Fermi level can be used in the modeling of physical observations. The Fermi surface topology is of importance to predict or explain the existence of instabilities of the electronic gas (nesting vector concept see Chapter 2 of this book). Fermi surfaces calculated from structural data can be compared to those observed by means of the Shubnikov-de Hass method in the case of two- or three-dimensional metals [152]. 

Fig. 6.20 Normal incidence polarized reflection spectra for the two forms of 6-XXXV (R = Cl) Imax and Imin coiTespond to the directions indicated on Fig. 6.19 (a) the (001) face of the triclinic structure (b) the (110) face of the orthorhombic form. (From Bernstein et al. 1979, with permission.)...

Fig. 6.23 Normal incidence polarized reflection spectra of the two forms molecule 6-XVII (R = Et, R = OH). For each crystal modiflcation there are two spectra measured with the light polarized along each of the two directions (the so-called principal directions), as indicated in the upper right hand corner, which also shows the projection of the molecule(s) onto the crystal face studied, (a) Triclinic polymorph, (100) face (b) monoclinic polymorph, (100) face. (From Tristani-Kendra and Eckhardt 1984, with permission.)...

In the theoretical and experimental discussion presented so far, we have not discussed any polarization effects such as (i) the dependence of the LSP resonances upon the incident polarization, or ( /) the nature of the polarization of the emitted fluorescence signal. This choice simplified the presentation of the principles of SPM in MEF and did not affect the interpretations of the experimental results, which were obtained fi"om NP arrays with no (or only a weak) polarization dependence. 

The incident polarization only affects the coupling to the LSP resonances at the laser frequency, i.e. the local field enhancement factor at... 

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