Optical considerations

Optical communications have an large capacity for the transmission of information and, in this respect, is far superior to 

Three basic types of optical fibers are produced by CVD (Fig. 16.8) as described below.h l 

Step-index Graded-index Multimode Multimode 

Step-Index Multimode. The step-index multimode fiber has a sharp difference between the index of refraction of the core and that of the cladding (Fig. 16.8a). Light propagation in such a fiber is 

Single Mode. The single-mode fiber has a step-index profile (Fig. 16.6c) and a small core diameter (typically 10 im) such that only one mode can travel through it. This is now the preferred system, particularly for long-distance transmission. The normal light source for multimode fibers is the light-emitting diode (LED). But 

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The absorption, fc, of the film at the wavelength of the probing light, 600 nm, was observed to increase monotonically with potential. Concomitant with k, the real part of the refractive index shows a steady decrease in value as soon as the potential is increased beyond —0.5 V. In addition, n can be seen to pass through an inflection at c. —0.2 V. On the basis of optical considerations, it is possible to infer from the behaviour of n that ... 

Optical Considerations Relevant UV Sources and Sunlight Absorption... 

The authors deeply acknowledge (i) R. Note and S. Ringensen (L OREAL Safety Research Department, Aulnay, France) for their precious advice in writing the section about in silico models (ii) F. Christiaens (L OREAL Applied Research, Clichy, France) for his help about optical considerations (iii) A. Labarussiat (L OREAL Safety Research Department, Aulnay, France) for her important contribution in preparing the final manuscript (iv) D. Averbeck (Institut Curie, Orsay, France) for critical reading of the manuscript. 

The Rayleigh approximation shows that the intensity of scattered light depends on the wavelength of the light, the refractive index of the system (subject to the limitation already cited), the angle of observation, and the concentration of the solution (which is also restricted to dilute solutions). In the Rayleigh theory, the size and shape of the scatterers (M and B) enter the picture through thermodynamic rather than optical considerations. 

To check whether eq. (1.5) is valid also for fluids of more general properties than those of the just described solution, flow birefringence, extinction angle and shear stress should be measured in a sufficient range of shear rates. When a plot is made according to eq. (1.5), a straight line should result. The fact that the shear rate is eliminated, indicates the quasistatic character of the stress-optical consideration. 

Film electrodes are generally fabricated from conducting or semiconducting materials, which may be deposited as a result of either a physical or a chemical process (or some combination) onto a suitable substrate, which is typically an insulator. Key factors governing the desired thickness of the film are the electrical resistivity (p) or conductivity (k = 1/p) of the film material, which is a practical consideration in almost all cases, and the optical transparency or reflectance of the material if optical transmission or reflection is also desired. The optimum film thickness for an application involving both electrical and optical considerations will require a trade-off, since a decrease in resistivity (usually desirable) normally is also accompanied by a decrease in light transmission (undesirable for an optically transparent electrode). 

Optical Considerations for Hollow-Waveguide-Based Gas Sensing. 144... 

Optical Considerations. The objective of this investigation was to determine the amount of water in coexisting phases of the C10PO system. The value of the data is therefore determined by the instrument s photometric accuracy. Several factors which contribute to photometric inaccuracies in infrared microspectroscopy include sample geometry, spherical aberrations caused by the introduction of... 

An optical consideration specific to the use of the TOF-MS with high-intensity sources is the removal of background ions, plasma gas ions, and matrix ions to prevent detector saturation. To date, this has been accomplished with parallel-plate deflection in the flight path, which is depicted in Fig. 12.6. Removal of specific m/z ions is accomplished by the application of a time-dependent potential to one, or both, of the plates at some time delayed with respect to the repeller pulse. In this way, those ions between the plates at the time of the pulse experience a field transverse to the flight axis and are removed from the flight path. The voltage pulses employed here must have fast rise and fall times (<10-20 nsec), and be applied at precise delay intervals to ensure that mass resolution is not compromised, and to allow for the unimpeded passage of the previous and subsequent masses. Also, the... 

There are yet other, purely optical considerations regarding the optimal roughness value for ZnO layers (some of these points are also discussed in Sect. 8.2.4.1) ... 

In the next section we will discuss the basic design rules for a non-planar, solid, inorganic solar cell with an extremely thin absorber layer. This type of cell has often been called the ETA cell (for extremely thin absorber Ernst et al, 2000) or ETA cell, and we will use the latter acronym here. Materials aspects, structural, electronic and optical considerations will be introduced. 

Optical consideration, metal-dielectric antireflection coating... 

Optical consideration, electrode with asymmetric reflection... 

Mathematical treatment of the corresponding wave equation under consideration of all boundary conditions yields a number m of discrete solutions of possible waves. These possible waves, the so-called modes, which depend on refractive indices no, ni, n2 and on the film thickness t are distinguished according to their different propagation constant I3m. The connection with a geometric optical consideration is given by ... 

Different techniques require that tissue be fixed and processed in a variety of different ways. This, in turn, influences how slides are prepared for compound micoroscopy. For example, different kinds of mounting media require different optical considerations. In particular, the refractive index of the mountant affects the spatial resolution that can be achieved for a given objective. 

In his Ph.D. thesis [61], Dhamelincourt detailed optical considerations for the design and implementation of a Raman microprobe and microscope, based on commercial optical microscopes, a design that was commercialized as the MOLE (Molecular Optical Laser Examiner) by Lirinord/Jobin Yvon. In this system, a beam splitter in a standard epi-illuminator (Fig. 3) was used to disentangle the incident laser beam from the Raman scattered beam. 

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