Frequency optical

Kieffer has estimated the heat capacity of a large number of minerals from readily available data [8], The model, which may be used for many kinds of materials, consists of three parts. There are three acoustic branches whose maximum cut-off frequencies are determined from speed of sound data or from elastic constants. The corresponding heat capacity contributions are calculated using a modified Debye model where dispersion is taken into account. High-frequency optic modes are determined from specific localized internal vibrations (Si-O, C-0 and O-H stretches in different groups of atoms) as observed by IR and Raman spectroscopy. The heat capacity contributions are here calculated using the Einstein model. The remaining modes are ascribed to an optic continuum, where the density of states is constant in an interval from vl to vp and where the frequency limits Vy and Vp are estimated from Raman and IR spectra. 

Abstract. The spectral dependence of photoluminescence and optical conductivity for the solid C6o and Cd-Q)0 films (with the admixture of C70 fullerenes) are studied under irradiation by argon ions with different doses. The fragmentation of the C6o molecules and the formation of the radiation defects, which are accompanied by appearance and increase in the intensity of the new component of the excitons emission, by decrease in the high-frequency optical conductivity spectral dependence to an analogous characteristic for the amorphous carbon films are observed with an increase in the radiation dose. This testifies that with the destruction of the molecules structure by ions the growth of the number of electrons, which are in the sp2 -hybridized state takes place. Furthermore, with the appearance of radiation defects the formation of the traps of the free charge carriers, which lead to a total decrease in the optical conductivity occurs. 

Figure 11.8. Hyperfine levels in OH and OD in the excited A2E+ state studied by radio frequency/ optical double resonance. The splittings are not to scale.

Figure 11.40. Hyperfine and spin-rotation splitting of atypicalrotational level intheX2E+ state of YO, and the magnetic dipole transitions observed by radio frequency/optical double resonance.

Abstract. The spectral dependence of photoluminescence and optical conductivity for the solid C60 and Cd-C6o films (with the admixture of C70 fullerenes) are studied under irradiation by argon ions with different doses. The fragmentation of the C60 molecules and the formation of the radiation defects, which are accompanied by appearance and increase in the intensity of the new component of the excitons emission, by decrease in the high-frequency optical conductivity o e) and... 

Fig. 10.5 High frequency optical modulators and switches (a) construction of a rib wave guide with microwave strip line upper electrode, and plan views of (b) Mach-Zehnder, (c) birefringent, and (d) bi-directional coupler modulators. Reproduced with permission of Wiley-VCH from Dalton et al. (1995).

Bosemberg, W.R., Guyer, D.R. Single-frequency optical parametric oscillator, Appl. Phys. Lett. 61, 387-389 (1993)... 

Raj R. K., Bloch D., Snyder J. J., Camy G. and Ducloy M., High-Frequency Optically Heterodyned Saturation Spectroscopy Via Resonant Degenerate Four-Wave Mixing , Phys. Rev. Lett. Vol. 44, 1980, pp. 1251-1254. 

FOTDR frequency optical time domain reflectometry... 

From Maxwell s theory of electromagnetic waves it follows that the relative permittivity of a material is equal to the square of its refractive index measured at the same frequency. Refractive index given by Table 1.2 is measured at the frequency of the D line of sodium. Thus it gives the proportion of (electronic) polarizability still effective at very high frequencies (optical frequencies) compared with polarizability at very low frequencies given by the dielectric constant. It can be seen from Table 1.2 that the dielectric constant is equal to the square of the refractive index for apolar molecules whereas for polar molecules the difference is mainly because of the permanent dipole. In the following discussion the Clausius-Mossoti equation will be used to define supplementary terms justifying the difference between the dielectric constant and the square of the refractive index (Eq. (29) The Debye model). 

RFODR radio frequency optical double resonance... 

On the other hand, it is seen from Fig. 5.10 that only the higher-frequency optical mode is involved in C L,zz(fc,w). This is because only the rotational motions give rise to the local charge-density fluctuations. (The translational motions do not due to the charge-neutrality of the solvent molecule.) Thus it is the higher-frequency nature of the optical... 

When we deal with the IR spectral range, the first two terms in Eq. (1.36) can be replaced to a good approximation by the value of the dielectric function at the frequency a> in the transparency region (1.2.4°), where only the valence electrons are assumed to contribute to the polarization (atomic centers are rigidly fixed). This value is called the high-frequency (optical) dielectric constant or the screening factor and denoted as oo[ oo = e((o) if o)oj In partic-... 

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