Reflection Reflectivity

Light reflectance (reflectance, reflectivity). The fraction of the total luminous flux incident upon a surface that is reflected, generally a function of the color (wavelength) of the light. Johnson SF (2001) History of hght and colour measurement a science in the shadows. Taylor and Francis, London, UK. Saleh BEA, Teich MC (1991) Fundamentals of photonics. John Wiley and Sons, New York. 

ATR Attenuated total reflection Reflected beam attenuated Similar to IR... 

Sampling reflectance reflectance diffuse integrating diffuse 180°... 

Specular and Diffuse Reflectance. Reflectance techniques have been applied primarily to samples which do not permit observation by transmission. Flat surfaces such as those of metal foils and single crystals can he studied by specular reflectance, whereas rough surfaces such as those of powders must be observed by diffuse reflectance. In both cases FT spectroscopy offers strong advantages in terms of the time required to acquire a spectrum. 

Completeness to 9 = 30.22° Reflections collected Independent reflections Reflections with F2 > 2a Absorption correction Min. and max. transmission Structure solution Refinement method Weighting parameters a,b D ata/re straints/parameters Final R indices [F2 > 2a]... 

Reflection. Reflection is also called mirror symmetry since the operation is that of a mirror plane in three dimensions, or an axis in two-dimensions, which reflects an object into another indistinguishable one. Consider a reflection in a plane parallel to b and c. The reflection essentially changes the algebraic sign of the coordinate measured perpendicular to the plane while leaving the two coordinates whose axes define the plane unchanged. Hence, W for a mirror reflection in the be (yz) plane takes the form ... 

Electromagnetic radiation has its origins in.itoiflic and molecular processes. Experiments demonstrating reflection, reflection, diffraction and interference phenomena show that the radiation has wave-like characteristics, while its emission and absorption are better explained in terms of a particulate or quantum nature. Although its properties and behaviour can be expressed mathematically, the exact nature of the radiation remains unknown. 

Five different optical phenomena are used for producing linear polarization dichroism, birefringence, reflection, reflection-transmission by metal gratings (grids), and scattering. 

Fresnel s equations can be used to calculate the dependence of the reflectivity [(reflected beam intensity)/(incident beam intensity)] on the incident angle expressed in terms of the scattering vector Q (Fig. 5),... 

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