Cross-polarized radiation

The triangles in Fig. 7.2 represent data for linearly or partially polarized radiation, while the circle is for cross-polarized radiation (this is the one exception mentioned previously). The experimental measurements are consistent with the following interpretation. The laser output consists of a number of more-or-less independent Fabry-Perot modes which are changing during the pulse width due to heating of the laser junction 1.2A, The radiation may therefore be considered to behave as a Gaussian source with a coherence time rj (dv) 10 s. Since the intermediate-state lifetime for the doublequantum sodium photodetector is much shorter than the radiation coherence time, the irradiance fluctuations result in a factor of 2 enhancement of the single-beam photocurrents. As far as the irradiance cross-term is concerned. 

We further considered the cross-polarized radiation of the multiband antenna, because polarization mismatch is unavoidable due to the individual s movements. As shown in Figure 10.25, the shoulder-mounted antenna stUl provides coverage in cross-polarization operation. This is because the antenna s surface shared the shoulder and arm sections of the body. The shoulder-mounted antenna did provide a good... 

Polypropylene molecules repeatedly fold upon themselves to form lamellae, the sizes of which ate a function of the crystallisa tion conditions. Higher degrees of order are obtained upon formation of crystalline aggregates, or spheruHtes. The presence of a central crystallisation nucleus from which the lamellae radiate is clearly evident in these stmctures. Observations using cross-polarized light illustrates the characteristic Maltese cross model (Fig. 2b). The optical and mechanical properties ate a function of the size and number of spheruHtes and can be modified by nucleating agents. Crystallinity can also be inferred from thermal analysis (28) and density measurements (29). 

CAL-4 was prepared according to the procedure described in reference 2. Powder XRD confirmed the absence of contaminant phases. 13C MAS NMR spectra were recorded under cross polarization conditions (CPMAS). Single-crystal XRD data were collected at room temperature using MoK radiation. 

SALS was performed using the apparatus described In the Hardware and Software sections. Samples were placed onto the sample holder and Illuminated with the laser. The scattered radiation was passed through the analyzer, with the system In the Hv mode (crossed polarizers). The Imaging screen was adjusted to maximize the pattern size. The camera position was then adjusted to maximize the... 

The Intensity of the scattered radiation Is the product of E and Its complex conjugate . Prud homme and Stein (39) examined the type of scattering to be expected from a material composed of rod-llke aggregates between cross polars (Hv mode). In the case of small... 

Figure 7.6. Plagioclase glass in the Asuka-881757 lunar meteorite is surrounded by radiating expansion cracks in pyroxene, (a) reflected light, (b) transmitted light, and (c) cross polarized light. The scale bar is 200 pm...

The index (a, [>) relates to the distinct energy of each photon, respectively that is, oc = when both photons have the same excitation frequency T = damping factor. The parameter cof denotes the excitation energies of the final excited states /), the summation includes the ground state 0), and /) corresponds to the virtual state. Definition of the TP matrix element yields the theoretical TPA cross section <5tp if a linearly polarized radiation source is applied [16, 23], Eq. (20) ... 

In a system for coherent forward scattering, the radiation of a primary source is led through the atom reservoir (a flame or a furnace), across which a magnetic field is applied. When the atom reservoir is placed between crossed polarizers scattered signals for the atomic species occur on a zero-background. When a line source such as a hollow cathode lamp or a laser is used, determinations of the respective elements can be performed. In the case of a continuous source, such as a xenon lamp, and a multichannel spectrometer simultaneous multielement determinations can also be performed. The method is known as coherent forward scattering atomic spectrometry [309, 310]. This approach has become particularly interesting since flexible multichannel diode array spectrometers have became available. 

The precise nature of a matrix site may be inferred from the occurrence of processes that axe forbidden in the gas phase, the removal of a gas-phase degeneracy (e.g., lifting of e//-orbital degeneracy in A > 0 states), or observation of polarization behavior (in amorphous matrices, the degree of fluorescence polarization resulting from linearly polarized excitation or, in single-crystal hosts, the dependence of the absorption cross-section for linearly polarized radiation on the orientation of the crystal axes). 

The cos a factor causes the differential cross-section to be small for small values of a so that plane-polarized radiation is preferentially scattered out of the plane of polarization ... 

For plane-polarized radiation, the differential cross-section is given by... 

Detailed analysis shows that after the second pulse three waves are emitted hy the coherently excited atoms. One of them is radiated in 2-direction and only originates from the second excitation. Of particular interest is that wave, which propagates in the direction of the first pulse, however, now with modified polarization and therefore can be monitored behind a crossed polarizer. Its intensity can be calculated to be proportional to ... 

The experimental set-up we used is shown in Fig. 2, A synchronously pumped mode-locked and cavity-dvunped dye laser, which can be timed to the D or Dj line of Cs, generates pulses of about 20 ps duration at a pulse rate of U MHz and peak powers of several hundred watt. They are split into linearly polarized pump pulses and stronger circularly polarized probe pulses, which pass an optical delay line. Both beams are focussed into a common interaction region where they act on the Cs vapor, which is contained in a cell at room temperature. The radiated wave propagating in pump pulse direction is detected by a photomultiplier, which measures the transmitted average intensity behind a crossed polarizer as a function of the delay time. 

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