EFISH second harmonic

Electric discharge ozone generator, 77 798 Electric-field-induced second harmonic generation (EFISH), 20 515 Electric field intensity, exponents of dimensions, 8 585t Electric field perturbations, 74 616 Electric fields... 

Using these and other design principles, very large increases in the valnes of chro-mophores have been obtained since the original work on the simple red monoazo dyes of the disperse dye class. These new NLO chromophores are known as high pP chromophores , a selection of which are shown in Figure 5.31, the pP values quoted being measnred by electric field induced second harmonic at (EFISH) 1.9 It... 

EFISH electric field-induced second harmonic generation... 

Electric Field Induced Second-Harmonic Generation. An essential aspect of the development of materials for second-order nonlinear optics is the determination of the p tensor components. The technique that has been developed to accomplish this is called electric field induced second harmonic generation (EFISH) (13,14). 

Third-Order NLO Techniques. There is a wider range of third-order techniques commonly used to characterize materials, including electric field induced second harmonic generation (EFISH) (15, 16), third harmonic generation (THG) (17) and degenerate four wave mixing (DFWM) (18). EFISH and DFWM will be discussed briefly then... 

Both theoretical analysis and dipole moment measurements indicated that sulfonyl-substituted compounds may have ft coefficients similar in magnitude to their nitro analogues. Therefore, we have measured p for several sulfonyl- and nitro-substituted compounds using electric-field-induced second-harmonic generation method (EFISH) (11,25). In this experiment, one measures an effective third-order nonlinearity rEFISH for a solution containing the compound of interest, given by... 

A detailed investigation of the NLO properties of molecules of series 2 and 3 has been performed in the powder state (12) as well as in solution by the electric-field-induced-second-harmonic (EFISH) generation method (13-15). It has allowed the analysis of the influence of the molecular parameters on the NLO features (12-15). 

The high viscosity of the PMMA damps out orientational contributions so that the yqeo that is measured is thought to be =60-90% electronic. This has been ascertained by measuring the electric field induced second harmonic generation (EFISH) below the Tg of the polymer. From this can be obtained the microscopic elastic constant, which can in turn be used to estimate the magnitude of the two orientational contributions to yQEO- Details are provided else where (13,16). 

Poly(3-alkyl-a-thiophene) systems show significant third-order nonlinear susceptibilities ( ) Though, oligothiophenes have been studied for their third-order susceptibilities, accurate third-order optical nonlinearity data obtained by degenerate four-wave mixing or electric-field-induced second harmonic generation (EFISH) are difficult to attain reliably on samples with poor solubility characteristics (92MM1901). 

TDDFT methods have also been applied successfully to the description of the linear and nonlinear optical properties of heteroleptic sandwich complexes. The optical spectrum and the hyperpolarizability of Zr(OEP)(OEPz,) for which large first hyperpolarizabilities, /JSHG (SHG=second-harmonic generation) were measured in an electric field induced second-harmonic generation (EFISH) experiment [182], have been investigated by TDDFT methods [134]. The excitation energies and oscillator strengths calculated... 

While the above discussion clearly highlights the importance of including solvent effects in the calculations, the calculated properties cannot be compared directly with experimental results. This is mainly caused by the many different conventions used for representing hyperpolarizabilities and susceptibilities. However, the calculated properties can be combined with appropriate, calculated Lorentz/Onsager local field factors to obtain macroscopic susceptibilities that can be compared with experimental results. For water, we used this to calculate the refractive index and the third harmonic generation (THG) and the electric field-induced second harmonic (EFISH) non-linear susceptibilities. The results are collected in Table 3-11. 

Xe<3)(—2ffl,0,co,co) Electric field induced second harmonic (EFISH)... 

Reiss has introduced a notation for combining the four microscopic variants of WRBS with field definitions defined by the m value. It might be preferable to keep the macroscopic adjustments separate from the molecular definitions. The question of the definition of the fields is related to the nature of the EFISH measurement. The essential observation is of the ratio between the intensity of second harmonic light emitted from the solution to that emitted by quartz standard. However the or-field is defined the ratio will be related to T by an equation (written schematically) of the kind,... 

The second harmonic contribution from requires an electrostatic electric field E() and is known as electric field induced second harmonic (EFISH). The intensity of the generated second harmonic, assuming that the film is very thin and lossless, is... 

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