Azimuthal polarization mode

Figure 7. Micro-photoluminescence spectra of the nanoneedle of Fig. 5 for D 790 nm at two different polarizer azimuth orientations shifted vertically for clarity. The modulation of the VIS band almost disappears when detecting the TE mode. Thus, the resonances are mainly TM polarized. The inset shows the ratio P = (Tm Te) (Tm + e), that visualizes the TM-WGMs as distinguishable peaks. The polarization effect has been found to be independent of the polarization of excitation.

We examined the effect of coupling between surface plasmon polariton (SPP) modes on the optical activity of metal nanostructures. By measuring the in-plane wave vector dependence on transmission and polarization azimuth rotation, we show that coupling of the SPP modes with orthogonal polarization localized at different interfaces is responsible for the optical activity in metal nanostructures. 

Two modes contribute to the value of the averaged polarization (P). The first of them (soft mode) is induced due to the amplitude change of the polarization, i.e., variation of the tilt angle 6. This mode is the most important near the phase transition point of the FLC phase and results in the electroclinic eflFect [19, 20, 36]. The second mode, called the Goldstone mode, is responsible for the variation of the phase of polarization, i.e., the azimuthal director angle (p. 

The nearly meridional polarization of the reflection at 12 nm (reflections (040)a of a form, or (008)y of y form) in the patterns of Fig. 11.6 and azimuthal profiles of Fig. 11.8a-c indicate that portion of the crystals of y form, or in disordered modifications intermediate between the y and a forms more similar to the y form, assume an orientation with the Cy-axis of y form (b -axis of a form) nearly perpendicular to the stretching direction (Fig. 11.2b, c) (De Rosa et al. 2005 De Rosa and Auriemma 2007 Auriemma and De Rosa 2006). Since the Cy-axis of y form (b -axis of a form) are the axes of stacking of the layers of chains (Fig. 11.2b, c) this non-standard mode of orientation of iPP crystals corresponds to lamellae oriented with chain axes nearly perpendicular to the fibre axis (Fig. 11.2b, c, and Scheme 11.3a ). 

Figure 5. Influence of different azimuthal angles 6 and polar angles

The components of the directional potentials are azimuthal and polar rotational potentials which determine the conformation of molecular chains, ie, valence angles, and cause their intrinsic stiffness. They are responsible for transverse bending modes which are combined with torsional modes. 

Using somewhat more sophisticated, the so-called radial and azimuthal, modes of polarization enabled the observation of tautomerism in single molecules of porphycenes [23, 24] (Figure 3.5) and porphyrins [25]. These techniques also allowed obtaining the 3D orientation patterns for single molecules of porphycenes embedded in a polymer film [24]. 

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