Interference pattern resulting from

Figure 2. An interference pattern resulting from the scattering from two particles.

Thus the resulting holoprojection is the product of a dynamic interference pattern resulting from at least two distinct signals, and is amenable to expression as mathematical transform coefficients analogous to the mathematical operations which describe optical holography. 

The modified Rayleigh interferometer [54] is based on the same principle. Half of the beam (ordinary or extraordinary) is passed through the planar-oriented nematic cell and the other half transverses to the empty part of the cell. When the two beams are mixed an interference pattern results, from which the refractive indices n and n can be determined separately. In particular, changes in the refractive indices can be measured with high accuracy, using this method. 

This effective Q,t-range overlaps with that of DLS. DLS measures the dynamics of density or concentration fluctuations by autocorrelation of the scattered laser light intensity in time. The intensity fluctuations result from a change of the random interference pattern (speckle) from a small observation volume. The size of the observation volume and the width of the detector opening determine the contrast factor C of the fluctuations (coherence factor). The normalized intensity autocorrelation function g Q,t) relates to the field amplitude correlation function g (Q,t) in a simple way g t)=l+C g t) if Gaussian statistics holds [30]. g Q,t) represents the correlation function of the fluctuat-... 

In many cases the photon can be represented by the two alternative models of a plane wave and a particle-like wavepacket. This should also apply to interference phenomena with individual photons [21]. For a given point at the screen of an experiment with two apertures, the resulting interference pattern obtained from individual photon impacts could thus be interpreted in two alternative ways ... 

Figure 12.1. Beat pattern resulting from interference between two similar frequencies.

Interference effects are not limited to simple two-level interactions. Stahel, et al., (1983) have performed a multilevel deperturbation (1E-matrix 41 levels matrix 30 levels) of the N2 and 1IIU states. Prior to the work of Dressier (1969), the numerous known N2 vibronic levels of 1E+ and 1IIU symmetry between 100,000 and 120,000 cm-1 had not been convincingly organized into separate electronic states. Dressier (1969) showed that the chaotic level and intensity patterns resulted from homogeneous perturbations of the b1 ... 

Sometimes, the autoionized lines for very large values of n near the ionization threshold present a regular pattern characterized by the appearance of fringes . This phenomenon has been attributed to a stroboscopic effect between the periodic orbital motion of the Rydberg electron and that of the ion rotation (in Na2, Labastie, et al, 1984, in Li2, Schwarz, et al., 1988) and an interference effect resulting from the relative phases of the 1-mixing matrix elements and transition moments (in NO, Fredin, et al., 1987), or an effect of finite resolution (in HC1, Drescher, et al., 1993). 

The interference fringes resulting from two planewaves will appear as straight Unes. Wavelronts do not have to be planewaves to produce an interference pattern, not do the wavefronts have to match each other in shape. Interference between arbitrary wavefronts can appear as concentric circles or elUpses or as wavy lines. 

When two sources of radiation with different wavelengths interfere, the interference pattern is less simple. A beat pattern results from such interference, as is illustrated in Fig. 6b. The function describing the amplitude of the interference pattern of two different wavelengths is 0.5[z(l. 0 + cos27t0/x )]. n=l,2... 

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