Refraction and Reflection

Let us consider a beam of incident light as it undergoes refraction on a flat plane, as shown in Table 1.1 (Refraction). A wave plane PP encounters the refractive plane at point P. The point P reaches the plane at points Q and Q after t seconds. If the light velocities in each medium are v, and v2, respectively, the relationship between the refractive angle and the light velocity is given by 

Let c be the light velocity in the vacuum, then the refractive index, n, is be defined by 

The refractive index of a large number of materials is known as a function of wavelength. Typical values range from 1.3-2.3 in the region of visible light. 

An unpolished diamond in our hand is not much more than an investment. An artfully polished diamond becomes an object of aesthetic value. The diamond cutting technique is ruled by the law of total reflection. 

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By placing these windows in a plane set at the Brewster angle with respect to the Ught beam, maximum transmission is assured (minimum reflection). The above considerations regarding polarization of refracted and reflected beams must be modified for nontransparent media such as metals, for which there is little polarization of a reflected beam. 

Figure 18.10 Magnitudes of refracted and reflected waves under different junction conditions.

Cable junction, low refraction and reflection. Arrester essential i V,> BIL of the cable... 

Note Cable junction b has a high refraction and reflection. Arrester would be essential to protect the cable rather than the transformer, if 2Vi > BIL of the cable. If the cable is long enough say. > 50 metre or so, the natural dampening of Ihe incident wave up to junction b may be enough and may not cause any harmful effect even without the arrester... 

The presence of mica in pearlescent pigments only partly accounts for the appearance of the pigment. A very thin layer of the inorganic oxide titanium dioxide (TiC>2) or iron oxide (Fe2C>3) or both is coated on the mica platelets. The various colors and pearlescent effects are created as light is both refracted and reflected from the titanium dioxide layers. The very thin platelets are highly reflective and transparent. With their plate-like shape, the platelets are easily oriented into parallel layers as the paint medium is applied. Some of the incident light is reflected... 

In CL measurements many factors that influence the intensity of the CL signal should be taken into account. The CL signal may depend on the geometry of the sample. Internal refraction and reflection at the air-solution interfaces are important factors in determining the measured CL intensity, and should be taken into account, for example, when a CL cocktail is placed over a sample. The effect of sample geometry can be evaluated using model systems, such as enzymes... 

From Snell s Law, sin(0j) m = sin(0j) nr. We have TIR when sin(Oj) > nr/rii, while we will have refraction and reflection when sin(0j) < nr/ni. In practical cases properties of light, such as phase, polarization and intensity, can be modulated inside the wave guide by a given measurand, which is interacting, for instance, with a CIM lying within the penetration depth for the evanescent field of the light localized near the external guide surface. 

FIGURE 13.8 Refraction and reflection of incident light at the surface of a solid. 

Pearlescence is the iridescence produced by refracted and reflected light from a surface (pearl-like colour). 

Figure 4.1. Refraction and reflection of incident light at the surface of a solid. The path of refracted light is indicated by R and that of reflected light by / 2.

You should see rainbow patterns from refracted and reflected visible light waves. Violet waves have the shortest wavelength and are refracted at the greatest angle, while red waves have the longest wavelength and are bent at the smallest angle. Therefore, rainbows always are red at the top and violet at the bottom. 

Rigorously, ORD and CD spectra are related through the Kronig-Kramers theorem, a well-known general relationship between refraction and absorption, i.e. nL - nR is determined by eL - % for A from zero to infinity [128], (The analogous relationship between refraction and reflection applies to cholesteric liquid crystals.) Hence, in order to maximize ORD in the transparent region, Cotton effects, associated with exciton coupling (both intramolecular and intermolecular), have... 

Moreover, Hirano et al. applied a model proposed by Chollet [98] to the quantitative estimation of the orientation of the long axis of the hydrocarbon chain. In the model, not only the refraction and reflection at air/LB film and LB film/substrate interfaces but also the optical rotation of electromagnetic wave due to the LB films is taken into account to obtain quantitative information about the molecular orientation. 

Bolton )R (2000 a) Calculation of Ultraviolet Fluence Rate Distributions in an Annular Reactor Significance of Refraction and Reflection, Wat. Res. 34, No. 13 3315-3324. 

FIGURE 12.1. Schematic representation of refraction and reflection of a plane electromagnetic wave at a boundary. The surface normal is taken along the z-axis, and the incident beam is assumed to be in the x-z plane (plane of incidence). 

PDT is based on the detection of scattered refraction and reflection pulses that sweep past a detector at different times as a particle traverses a narrow laser sheet. In conjunction with Mie scattering and time-of-flight velocity measuring technique, detailed distributions of particle size from 2 pm to 6000 pm are provided together with particle velocities from 0.5 m s to 150 m s. A miniaturized particle size velocimeter developed by Metrolaser is the first of its kind to utilize this technique. 

Figure 3.36. Refraction and reflection at an interface between media of refractive indices and 2 below, at and above the critical angle, 6 ( i > 2).

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