Incidence angle dependence

Figure 4. Incident angle dependence of E L and E L2/cos Q on highly reflecting metal surface [9].

The out-of-plane orientation of chromophores can be more easily controlled in LB films as compared with the in-plane orientation. Many chromophores are known to show anisotropic orientation in the surface normal direction. The molecular structure of chromophores and their position in amphiphile molecules, the surface pressure, the subphase conditions are among those affect their out-of-plane orientation. The out-of-plane orientation has been studied by dichroic ratio at 45° incidence, absorbance ratio at normal and 45° incidence, and incident angle dependence of p-polarized absorption [3,4,27,33-41]. The evaluation of the out-of-plane orientation in LB films is given below using amphipathic porphyrin (AMP) as an example [5,10,12]. 

Number of deposited bilayer Fig. 15. The incident angle dependences Fig. 16. The dependence of SH intensity at... 

Cationic magnetic Fe304 particles have been sandwiched between the polar headgroups of arachidate-ion monolayers deposited on oxidized silicon substrates [796]. Optical thicknesses of the SiOz layer on the substrate, the arachidate ion monolayers (A ), and the Fe304 particles thereon have been characterized by incident-angle-dependent reflectance measurements, assuming that these components possess stratified planar structures. The determined... 

Figure 15 Incident angle dependences of the p-polarized absorbance of 4,4 -bipyridinium radical cations in LB films at 400 nm after correction of the decay and optical path length for photoexcited (a) HV2+/AA and (b) AV2+/AA systems. The solid lines are calculated dependences.

The incident angle dependences of measured reflectance of a probe beam at 543 nm are shown in Fig. 30 for a polystyrene film containing SP with a weight ratio of 10 1. Each dip shows the SPR for a silver film (a) and the guided TM wave mode for the composite thin film (b) before and (c,d) after excitation by a... 

Figure 30 Incident-angle dependences of observed reflectance of a glass slide covered with (a) a silver film (50 nm) alone, and the SP in polystyrene (1 10) film (264-nm thick), (b) before, and (c) and (d) after ns laser excitation (1.25 and 2.5 mJ/pulse, respectively)...

Figure 6.13 Incident angle dependence on the rocking curve FWHM of Pb(Zro.52Tio.48)03 thin films and the penetration depth (calculation).

The site dependence of the PES produces diffraction of scattered molecules, which we shall discuss in Section 5. The corrugation can also be probed by examining the incidence angle dependence of the dissociation. This is commonly discussed in terms of the scaling of the dissociation, writing... 

W. Eckstein, A. Sagara, K. Kamada Incident angle dependence of sputtering yields for hydrogen bombardment of light elements. J. Nucl. Mater. 150, 266 (1987)... 

As already mentioned, the reflection modulation technique is relatively simple but for thicker or absorbing thin films it becomes much more complicated due to the multiple reflection effects in the used multilayer structure (Fig. 1) which may lead to erroneous results, if not correctly taken into account [10,20]. In that case, the measurement of the incidence angle dependence of the modulation intensity is required. Through a correct analysis of experimental data one can get both real and imaginary parts of r, as well as its anisotropy and ri3 tensor components). 

Figure 20 shows the incidence angle dependence of SHG intensity at pp fundamental - harmonic beam polarization configuration for a vacuum evaporated BAG thin film, showing very similar dependence as poled polymers with point symmetry oomm. This dependence can be well described by the formulas derived for this symmetry [50]. The fact that the measured quadratic NLO susceptibilities... 

Figure 20. Incidence angle dependence of SHG intensity for a thin film of benzylic amide [2] catenane. Full squares depict a least square fit to experimental data with fi.dij suceptibiUty tensor...

Figure 26. Incidence angle dependence of THG intensity for vacuum evaporated BAG film at 1064 nm...

Image equalisation to correct for the incidence angle dependence of the sea surface radar backscatter ... 

The optimum optical conditions (the angle of incidence and polarization of the incident infrared radiation) for ATR-SEIRAS depend on the thickness and morphology of the thin metal film [8-10, 31], Figure 8.5 shows the simulated incident-angle dependence of the band intensity of a model molecule adsorbed on an Ag film for p-polarization, where the metal film was assumed to be a bilayer consisting of a continuous underlayer and a nanoparticle overlayer [11]. 

Fig. 8.5 The incident angle dependence of the band intensity in ATR-SEIRAS for p-polarization (a model calculation). Band intensity is negligibly small for s-polarization [11],...

In relation to the molecular alignment, incident angle-dependent polarized absorption spectroscopy [31, 32] of thin films gives important information on the electronic states of the molecules and their interaction in the solid disordered system (i.e. thin films). This method is based on measuring the polarized... 

Figure 11.7 Incident angle-dependent polarized absorption spectra of DMQtT thin film. From 5. Hotta, Y. Ichino and Y. Yoshida, Molecular alignments and spectroscopy in thin films of thiophene-based oligomers, in Electronic and Optical Properties of Conjugated Molecular Systems in Condensed Phases, ed. S. Hotta, Research Signpost, Trivandrum, 2003, pp. 615-635. Reprinted with permission from Research Signpost, Copyright (2003) Research Signpost...

Figure 11.8 Incident angle-dependent polarized absorption spectra of BP1T thin film. Reprinted with permission from S. Hotta, Y. Ichino, Y. Yoshida and M. Yoshida, Spectroscopic features of thin films of thiopheneYphenylene co-oligomers with vertical molecular alignment, J. Phys. Chem., B 104(44), 10316-10320 (2000). Copyright 2000 American Chemical Society...

The surface PSD function can be calculated from the BRDF through a scatter model. For example, the grating equation model discussed in Section 2.3.2 shows that high-frequency surface perturbations will scatter light far from specular and low-frequency perturbations will scatter close to specular. The PSD shows the amount of modulation versus / that is, the square of the Fourier transform of the surface profile. Because it is a sample property, the same PSD should be obtained regardless of wavelength- and incident angle-dependent differences in the BRDF data. 

The incident angle dependence of the optical retardation of polyimide films on quartz substrates is shown in Pig. 2.8. Measuring the azimuthal and polar angle... 

Pig. 2.15 Incident angle dependence of the peak intensity for (a) BPDA-C8 and (b) BPDA-C7 polyimides. Model structures of (c) BPDA-C8 (trans-transoid) and (d) BPDA-C7 (trans-cisoid). Reproduction by permission from [46],... 

Fig. 2.16 Experimental geometries for the measurements of the polarization angle dependence (a) and the incident angle dependence (b) of IR absorption. 4>in is the polarization angle, which is defined by the angle between the rubbing direction and the analyzer direction. Oin is the incident angle of the IR light. The polarization angle and the incident angle were varied by rotating the sample around the Z and the Y axes, respectively. Reproduction by permission from [50].

Fig. 2.27 Best-fit parameters obtained from fitting the data for the incident angle dependence of IR absorption of rubbed An-Yl films. Reproduction by permission from [59].

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