Light reflection/transmission

The light reflected by a powdered solid will consist of a specular reflection component and of a diffuse reflection component. The specular component represents reflection of the incident light by the surfaces of the component particles, and it is characterized by a complete absence of light transmission through the interiors of the particles. By contrast, diffuse reflectance is associated with the radiation that penetrates into the particles to some extent and that then emerges from the bulk solid. This light will exhibit spectral characteristics that are modified from those of the incident beam by the electronic transitions that took place within the solid phase and at the boundaries of the component particles. 

Diffraction of light by transmission and reflection gratings was used to demonstrate the existence of light waves and led to the development of the diffraction equation. 

Normal reflection optics have been used to advantage with bulk electrode materials. Examples of this type of spectroelectrochemical cell are shown in Figure 9.11 [67]. Simple bifurcated fiber-optic waveguides are used to direct source light onto reflective bulk electrode surfaces and to collect the reflected light for transmission to a detector. This is a simple means for performing spectroelectrochemical experiments at bulk metal electrodes that cannot be as... 

Ie is the true scattered intensity I e is the measured scattered intensity at angle 6, and Z i8o-e is at the supplementary angle. fa and fi are the Fresnel s coefficients for the fractions of light reflected at perpendicular incidence at the glass-air and glass-liquid interfaces, respectively ta and tx are the corresponding transmission coefficients. They are defined by the following equations ... 

Optical microscopy (OM) Reflection Transmission Phase contrast Polarized light... 

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