Optical analogy

In our optical analogy, they permit calculating the stroboscopic point (pu9i) if one knows (p0,9>0) then (pz,[Pg.367]

Figure 5. Schematic arrangement for hologram formation with an electron biprism. A plane wave illuminates the specimen placed off-axis. After the object lens a wire is placed between two earthed plates. The wire is the electron optical analog of a Fresnel biprism and causes the unperturbed and perturbed waves forming the electron hologram to interfere. The object phase-shift causes a displacement in the hologram fringes, and is thus observable.

Figure 8. MMW/optical analog—waveguide/beam waveguide.

Tickle, 1899). Which of the two oxygens was the site of proton addition became clear only when Hantzsch (1919) demonstrated the close optical analogy between the salts and methiodides of dimethyl-pyrone and pyridinium salts and argued that a benzene-like ring arises in the pyroxonium salts [191]. The discussion of the structure... 

Figure 4.54. Resolution Alfects the Quality of an Image. The effect of resolution on the quality of a reconstructed image is shown by an optical analog of x-ray diffraction (A) a photograph of the Parthenon (B) an optical diffraction pattern of the Parthenon (C and D) images reconstructed from the pattern in part B. More data were used to obtain image D than image C, which accounts for the higher quality of image D. [(A) Courtesy of Dr. Thomas Steitz. (B) Courtesy of Dr. David DeRosier).]...

Betts, G.E. Linearized modulators for suboctave-bandpass optical analog links, IEEE Trans. Microwave Theory Tech. 42, 2642—2649 (1994)... 

Figure 3.47 Resolution affects the quality of an image. The effect of resolution on the quality of a reconstructed image is shown by an optical analog of x-ray diffraction ...

Optical mixing techniques are the optical analogs of the beating techniques developed in radio-frequency spectroscopy (Forrester, 1961). They have made possible the application of light scattering to the study of the dynamics of relatively slow processes such as macromolecular diffusion, the dynamics of fluctuations in the critical region/and the motility of microorganisms. 

An extremely useful description of coherence effects in two-level systems may be given by representing the effect of the laser field on the ensemble of molecules in the form of the well-known optical analog of the Bloctf equations in the rotating frame ... 

Fourier synthesis, as shown by the optical analogy in Figure 4.54. A resolution of 6 A reveals the course of the polypeptide chain but few other structural details. The reason is that polypeptide chains pack together so that their centers are between 5 A and 10 A apart. Maps at higher resolution are needed to delineate groups of atoms, which lie between 2.8 A and 4.0 A apart, and individual atoms, which are between 1.0 A and 1.5 A apart. The ultimate resolution of an x-ray analysis is determined by the degree of perfection of the crystal. For proteins, this limiting resolution is usually about 2 A. 

Similar to the optical analogy, the problem is solved by acoustic quarterwave matching layers (Fig. 10). Silica aerogels with densities of around 300 kg/m have the ideal acoustic impedance to match a piezoelectric transducer to air [77]. In addition, they exhibit rather low attenuation, as opposed to many porous, polymer materials used for this purpose until now. An increase in sound transmittance by more than 30 dB was achieved in a relatively simple arrangement without optimization. More elaborate designs, eventually including multiple layers combining different materials, will probably result in transducer systems optimized with respect to output power, sensitivity, and bandwidth. 

Optical analogies of the MOssbauer effect have been widely Investigated and such lines have been observed in a variety of crystals. It is of Interest that Haarer (22) has found a similar phononless absorption peak in the crystal of the charge-transfer complex between anthracene and pyromellitlc-acld-dlanhydrlde at very low temperatures (2-7 K). Thus it would seem that such resonatlve peaks are characteristic of transitions involving large deformation in a suitable space. 

Spectral hole burning is an optical analog of the radio frequency saturation experiments in nuclear magnetic resonance (NMR) as introduced in the famous work by Bloembergen, Purcell, and Pound in 1948. The NMR saturation experiments are dynamic in nature, that is, the hole or the saturation dip relaxes with a rate constant as given by spin-lattice relaxation. The analogous experiment in the optical domain was performed for the first time by Szabo. In the optical domain, the relaxation processes... 

In addition to the relation of hole burning techniques to dynamic saturation methods, it is also important to stress the close relation to another rather different technique, namely, Mossbauer spectroscopy. The hole burning technique has been called the optical analog of the Mossbauer effect. The relation is very close, indeed. On the one hand, both techniques work at the ultimate limit of resolution given by the natural line width. It is not the lasers which limit the resolution in hole burning it is the fast excited state lifetimes which set the resolution limit. For organic dye molecules these lifetimes are in the nanosecond time regime. Conse-... 

At the creation of quantum physics, optical analogs did play an important role in formulation of new wave mechanics. Many years later, in the second half of the XX-th century, thorough examination of phenomena associated with wave propagation in solids and nanostructures, the quantum theory of solids made a distinguished impact on photonic engineering and understanding of principal nanophotonic issues. In this paper, a brief historical overview is provided in support of the above statement. 

---