Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Incident Field

The equation (1) assumes the knowledge of the incident field E (r) which is the electrical field in the anomalous domain considering the flaw absent. This field must be computed before and one can imagine that small errors in estimation of this field may 2586... [Pg.328]

In this case, we can conclude that the small sensor is lightly tilted with an angle of 0,25 degrees. We have concluded, during experimentations, that the measurement of the magnetic field is very sensitive to the angle of inclinaison of the sensor. In this way, we validate the computation of the incident field E (r). We can also expect some difficulties for the validation of the forward problem by experimental data. [Pg.329]

We first supposed that the field radiated into the piece by the transducer is known, thanks to the Champ-Sons model. Then, the main approximation used consists in making far field assumptions in the beam defect interaction area. In the case of a focused transducer we assume that the incident wavefronts on the defect are plane. This is equivalent to say that the defect is located in or near the transducer focal area and that a defect located outside this zone does not cause a significant echo. In the case of planar contact transducer, the incident wavefronts on the defect are assumed to be spherical The incident field on the defect is therefore approximated by the product of a spatial function gfp,0,z)describing the amplitude distribution in the beam and a time-delayed waveform < ) ft) representing the plane or spherical propagation in the beam. The incident field on the defect can therefore be approximated for ... [Pg.738]

For stronger fields the relationship between the macroscopic polarization and the incident field is non-linear. The general relation between P and E is written as... [Pg.225]

The last relation in equation (Al.6.107) follows from the Fourier convolution theorem and tlie property of the Fourier transfonn of a derivative we have also assumed that E(a) = (-w). The absorption spectmm is defined as the total energy absorbed at frequency to, nonnalized by the energy of the incident field at that frequency. Identifying the integrand on the right-hand side of equation (Al.6.107) with the total energy absorbed at frequency oi, we have... [Pg.258]

Nomially the amplitude of the total incident field (or intensity of the incident light) is such that the light/matter coupling energies are sufficiently weak not to compete seriously with the dark matter Hamiltonian. As already noted, when this is tire case, tlie induced polarization, P is treated perturbatively in orders of the total electric field. Thus one writes... [Pg.1181]

Consider all of the spectroscopies at third order s = 3). To be as general as possible, suppose the total incident field consists of the combination of three experimentally distinct fields (/ = 1, 2, 3). These can differ in any combination of their frequency, polarization and direction of incidence (wavevector). Thus the total field is written as... [Pg.1183]

The unique feature in spontaneous Raman spectroscopy (SR) is that field 2 is not an incident field but (at room temperature and at optical frequencies) it is resonantly drawn into action from the zero-point field of the ubiquitous blackbody (bb) radiation. Its active frequency is spontaneously selected (from the infinite colours available in the blackbody) by the resonance with the Raman transition at co - 0I2 r material. The effective bb field mtensity may be obtained from its energy density per unit circular frequency, the... [Pg.1197]

CARS spectroscopy utilizes three incident fields including a pump field (coi), a Stokes field (CO2 C02nonlinear polarization at cOcars = 2c0i — CO2. When coi — CO2 coincides with one of the molecular-vibration frequencies of a given sample, the anti-Stokes Raman signal is resonantly generated [22, 23]. We induce the CARS polarization by the tip-enhanced field at the metallic tip end of the nanometric scale. [Pg.29]

The principal frequency dependence in Eq. (8.4) comes through the c and d coefficients. These coefficients demonstrate resonant poles at which the fields at specific locations within the particle can rise by orders of magnitude over the incident field. The wave vector values at which this occurs can be easily found by examining the form of the coefficients ... [Pg.349]

Figure 8.4. The ratio of the volume-averaged local field to the square of the incident field El, for a particle S /an in diameter and having a refractive index m = 1.47 + 10 6 i. Figure 8.4. The ratio of the volume-averaged local field <E E > to the square of the incident field El, for a particle S /an in diameter and having a refractive index m = 1.47 + 10 6 i.
NFPA 906. Guide for Fire Incident Field Notes. National Fire Protection Association, Quincy, MA. [Pg.431]

NFPA 906M—Guide for Fire Incident Field Notes. This section contains a series of forms that can assist the investigator in taking notes in an organized manner while collecting data about the incident. These forms can be supplemented by other data that each facility will find useful to collect. [Pg.172]

Unlike in bulk nonlinear spectroscopy experiments, the signal in nonlinear microscopy is generated within a volume that is on the order of an optical wavelength. The axial extent of this volume is often referred to as the interaction length, which denotes the length within which the incident fields interact to produce a nonlinear polarization in the material. Such microscopic interaction lengths yield signal interference profiles that can differ markedly from those observed in macroscopic spectroscopy. [Pg.214]

We will assume that all the incident fields are polarized in the x-direction. The pump and Stokes focal fields, which each look like the complex fields depicted in Figure 9.1, set up an effective CARS excitation field E = (r) (r). The anti-Stokes polarization in the excitation volume induced by the effective excitation field can be considered as a collection of radiating dipoles. The resulting CARS amplitude at any far-field point Q with coordinates R = (R, 6, (j)) is a sum of the amplitude contributions form all these dipoles and is given by... [Pg.218]

In order to realize molecular-vibration spectroscopy, coherent anti-Stokes Raman scattering (CARS) spectroscopy is employed, which is one of the most widely used nonlinear Raman spectroscopes (Shen 1984). CARS spectroscopy uses three incident fields including a pump field (< i), a Stokes field (0)2, 0 2 < 1) and a probe field (<0/ = <0i), and induces a nonlinear polarization at the frequency of <03 = 2<0i - <02 which is given in a scalar form by... [Pg.252]

Fig. 12 Optical near-field intensity distribution at the siuface of spherical gold nanoparticle with radius of 50 nm, calculated by FDTD technique. The incident field (1,0,0) was polarized along the y-axis the field monitor plane is perpendicular to the wave propagation direction (z-axis) and located at a distance of 70 nm from the center of the sphere... Fig. 12 Optical near-field intensity distribution at the siuface of spherical gold nanoparticle with radius of 50 nm, calculated by FDTD technique. The incident field (1,0,0) was polarized along the y-axis the field monitor plane is perpendicular to the wave propagation direction (z-axis) and located at a distance of 70 nm from the center of the sphere...
Optical frequency up-conversion, or second harmonic generation (SHG), in nanostructured surfaces can be also considered as a kind of field enhance-menf [61]. In general, SHG efficiency is proportional to the square of nonlinear polarization ha (x [P (2second order susceptibility. For a nanostructured surface, the incident field is transformed to the local field given by Eq. 19, yielding ... [Pg.181]

The incident field may be written E0 = EReR + ELeL, where... [Pg.49]


See other pages where Incident Field is mentioned: [Pg.142]    [Pg.326]    [Pg.328]    [Pg.329]    [Pg.663]    [Pg.739]    [Pg.1180]    [Pg.1180]    [Pg.1184]    [Pg.1188]    [Pg.1189]    [Pg.1197]    [Pg.1204]    [Pg.1207]    [Pg.1208]    [Pg.1208]    [Pg.1252]    [Pg.1273]    [Pg.672]    [Pg.23]    [Pg.35]    [Pg.259]    [Pg.209]    [Pg.348]    [Pg.350]    [Pg.41]    [Pg.219]    [Pg.254]    [Pg.264]    [Pg.5]    [Pg.10]   


SEARCH



© 2024 chempedia.info