Standard optical axis

By considering only elastic scattering events, the interaction of the specimen with the electron beam can be described through a complex transmission function (object wave-function) 0(f) which represents the ratio between the outgoing and the incoming electron wave-functions f = (x, y) is a two-dimensional vector lying on a plane perpendicular to the optic axis z which is parallel, and in the same direction, to the electron beam. In the standard phase object approximation ... 

In a microscope, standard polarized epi-illumination cannot distinguish order from disorder in the polar direction (defined as the optical axis) because epi-illumination is polarized transverse to the optical axis and observation is along the optical axis at 180°. However, microscope TIR illumination can be partially polarized in the optical axis direction (the z-direction of Section 7.2) and can thereby detect order in the polar angle direction. Timbs and Thompson(102) used this feature to confirm that the popular lipid probe 3,3 -dioctadecylindocarbocyanine (dil) resides in a supported lipid monolayer with its dipoles parallel to the membrane surface, but labeled antibodies bound to the membrane exhibit totally random orientations. 

When neither s-polarized light (light polarized perpendicular to the plane of incidence) is converted into p-polarized light (light polarized parallel to the plane of incidence) nor vice versa, standard SE is applied. This is the case for isotropic samples and for uniaxial samples in the special case, where the optical axis is parallel to the sample normal, for example (0001) ZnO [119]. 

Figure 1.6 Pair of particles irradiated by two counter-propagating beams designated primary ( i, fci) and ( 2. 2) (standard optical binding) and secondary beams ( 3, 3) reflected with transverse polarization as ( 4, 4). The angle subtended by the interparticle displacement vector R on the y axis is 0, and the angle between the R projection on the zx plane and thex-axis is f.

In principle the wavelength of irradiation and excitation are the same. The excitaticm light source is used to cause the photoreaction. By these means monochromatic irradiation is used automatically. A typical cell compartment is given in Fig. 4.22. The sample is stirred and temperature controlled. Three positions are mounted tilted at 45 relative to the optical axis of the excitation light beam. One position is for the cell with the solvent, one for the fluorescence standard, and the third for the sample itself. These three positions... 

The tensor component magnitudes for quartz are well characterized for an incident laser beam near the fundamental wavelength of 1064 nm [27J. The X333(2, tensor component for quartz is an accepted standard [28]. As the quartz standard is rotated about the optic axis of the crystal, the maximum of the largest Maker fringe is found near normal incidence of the incident laser beam and used as a measure of for quartz. 

Fig. 13.4 The standard optical arrangement for the Phase Doppler Anemometry (PDA) [13, 57]. The incident beams correspond to the same optical arrangement as used in the LDA technique. The two detectors are positioned out of the plane of the incident beams at an angle (j>r (named the off-axis angle). The detectors are also placed symmetric out of the x — y plane by the angles V>(= ip, tl>2) (called the elevation angles). The intersection angle of the two beams is denoted by 0 (referred to as the beam crossing angle). The figure is drawn based on a similar sketch from Albrecht et al. [5]...

Quartz, since it is a piezoelectric and not a ferroelectric, has no hysteresis loss when it oscillates, thus quartz crystal oscillators are widely used as frequency control devices in radios, computers, and watches. Since the frequency is a function of the mass of the crystal, they can serve as deposition monitors (quartz crystal microbalances) with sensitivities of less than 1 ng. By functionalizing the surface to absorb specific gases, they can also act as chemical sensors. The temperature sensitivity of a quartz crystal oscillator can be minimized by choosing the cut of the crystal relative to the optical axis, which is necessary for its use as a frequency standard. On the other hand, a cut can be chosen to maximize the frequency dependence on temperature and quartz crystal thermometers with millikelvin resolution are available. 

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