Reflected fight

If the reflected fight intensity of a clean plate (7g) is combined with the reflected value (or the spectrum) of the TLC spot (J) as... 

The reflected fight intensity of the plain plate 7g can easily be taken at a surface area free of any other compounds. In this equation, m indicates the mass of the... 

Chromium(III) (0,0 -diethyl dithiophosphate) forms beautiful flakes which are purple by reflected fight and di-chroic by transmitted fight they are purple at one angle and green at another. The salt is soluble in organic solvents but insoluble in water. It is stable toward air and water, but decomposes at temperatures above its melting point. 

Another important parameter for the film is thickness. The film thickness must be an odd integral multiple of A/4 for the wavelength of fight to be affected. To see how a film of this thickness and refractive index accomplishes attenuation or extinction of reflected fight, examine Figure 9.9. 

In reflectance photometry, diffuse reflected fight is measured. The reflected light results from illumination, with diffused light, of a reaction mixture in a carrier or from the diffusion... 

Again there is a light transmitter (e.g., an infrared LED) to illuminate a code disc. The code disc is made of a translucent material and is illuminated by the transmitter. A spiral shaped prism in the surface of the translucent code disc reflects the light perpendicular to the surface. Directly under the code disc there is a CMOS line sensor detecting the reflected fight. An additional reference prism in the code disc makes it possible to eliminate effects of a radial clearance. 

A dual-wavelength SPR imaging was proposed by Zybin et al. [48], who used two laser diodes which were switched on sequentially, and the intensities of the reflected fight at the two different wavelengths were measured (Fig. 16). The sensor output was defined as a difference of these two signals. A refractive index resolution as low as 2 x 10 RIU was achieved when averaging over a large beam diameter (6 mm ) was used. 

A classical elhpsometer, where the analyzer has to be rotated to record the whole ellipse of the reflected fight wave, can be improved by using a photoelastic modulator (PEM) [43]. In this case, the polarizer and analyzer are crossed in a fixed position and a photoelastic modulator is inserted behind the polarizer as shown in Fig. 4.2. The measurements with a photoelastic modulator are faster whereas the sensitivity is slightly worse compared to rotating analyser method. 

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