Refractive index dispersion associated with

At the top of Figure 6.15, the refractive index dispersion associated with an optical transition at a frequency greater than 2o) is schematically illustrated. The diflFerence in refractive index A q produces a phase diflFerence A< ) after the waves have traversed a distance L. Phase-matched versus non-... 

Material Dispersion—The dispersion associated with a non-monochro made light source due to the wavelength dependence of die refractive index of a material or of the light velocity in this material. 

Not all emulsions exhibit the classical milky opaqueness with which they are usually associated. A tremendous range of appearances is possible, depending upon the droplet sizes and the difference in refractive indices between the phases. An emulsion can be transparent if either the refractive index of each phase is the same, or alternatively, if the dispersed phase is made up of droplets that are sufficiently small compared with the wavelength of the illuminating light. Thus an O/W microemulsion of even a crude oil in water may be transparent. If the droplets are of the order of 1 pm diameter a dilute O/W emulsion will take on a somewhat milky-blue cast if the droplets are very much larger then the oil phase will become quite distinguishable and apparent. Physically the nature of the simple emulsion types can be determined by methods such as [95] ... 

TF1V has a unique combination of properties that include relatively low processing temperatures, bondability (to itself and other substrates), high flexibility, excellent clarity, low refractive index, and efficient electron-beam cross-linking.91 It also exhibits properties associated with fluoroplastics, namely, very good chemical resistance, weatherability, low friction, and low flammability. Typical properties of the dry grades are summarized in Table 3.9 and those of THV in aqueous dispersion form in Table 3.10. 

If we ignore the small effect of two-phonon transitions on the dispersion of the refraction index n, then in the region of the energies E = hu>, corresponding to the excitation of two-particle states, the absorption coefficient n is found to be directly associated with the density of two-particle states. In fact, for light polarized, for instance, along the x-axis, which coincides, by definition, with the direction of the vector dBB, the dielectric tensor has a nonvanishing component... 

Basically, birefringence is the contribution to the total birefringence of two-phase materials, due to deformation of the electric field associated with a propagating ray of light at anisotropically shaped phase boundaries. The effect may also occur with isotropic particles in an isotropic medium if they dispersed with a preferred orientation. The magnitude of the effect depends on the refractive index difference between the two phases and the shape of the dispersed particles. In thermoplastic systems the two phases may be crystalline and amorphous regions, plastic matrix and microvoids, or plastic and filler. See amorphous plastic coefficient of optical stress compact disc crystalline plastic directional property, anisotropic ... 

The modified resonator configuration for the mode-locked Ti sapphire laser is shown in Figure 4.14b note the inclusion of a pair of prisms in the cavity, which provide compensation for temporal dispersion in the resonator (the effect of propagation delays of different spectral component in the laser, associated with refractive index changes of the laser crystal, which broadens ultra-short pulses). The shortest pulses that can routinely be achieved using such a resonator configuration are of the order 20-30 fs. 

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