means of density and refractive index determinations, and the chemical composition also discover a relation involving these two variables which indicates the composition of any silicate indebted for help and advice. Mr. M. H. Hey of the. Relation between Refractive Index and Density of Glasses Resulting from Annealing Compared with Corresponding Relation Resulting from Compression. with respect to refractive index please have a look at the answers of James and me of a Article Relationship between composition, density and refractive ind.
Most of the radiation from oscillating material charges will modify the incoming wave, changing its velocity.
Refractive index - Wikipedia
However, some net energy will be radiated in other directions or even at other frequencies see scattering. Depending on the relative phase of the original driving wave and the waves radiated by the charge motion, there are several possibilities: This is the normal refraction of transparent materials like glass or water, and corresponds to a refractive index which is real and greater than 1. This is called "anomalous refraction", and is observed close to absorption lines typically in infrared spectrawith X-rays in ordinary materials, and with radio waves in Earth's ionosphere.
It corresponds to a permittivity less than 1, which causes the refractive index to be also less than unity and the phase velocity of light greater than the speed of light in vacuum c note that the signal velocity is still less than c, as discussed above. If the response is sufficiently strong and out-of-phase, the result is a negative value of permittivity and imaginary index of refraction, as observed in metals or plasma.Pharma Industry — Density and Refractive Index Measurement
This is light absorption in opaque materials and corresponds to an imaginary refractive index. If the electrons emit a light wave which is in phase with the light wave shaking them, it will amplify the light wave.
This is rare, but occurs in lasers due to stimulated emission. It corresponds to an imaginary index of refraction, with the opposite sign to that of absorption.
Dispersion[ edit ] Light of different colors has slightly different refractive indices in water and therefore shows up at different positions in the rainbow. In a prism, dispersion causes different colors to refract at different angles, splitting white light into a rainbow of colors. The variation of refractive index with wavelength for various glasses. The shaded zone indicates the range of visible light.
Dispersion optics The refractive index of materials varies with the wavelength and frequency of light. Dispersion also causes the focal length of lenses to be wavelength dependent. This is a type of chromatic aberrationwhich often needs to be corrected for in imaging systems.
In regions of the spectrum where the material does not absorb light, the refractive index tends to decrease with increasing wavelength, and thus increase with frequency.
This is called "normal dispersion", in contrast to "anomalous dispersion", where the refractive index increases with wavelength. In Unit 10 of The Physics Classroom Tutorialthe particle-to-particle interaction mechanism by which a mechanical wave transports energy was discussed in detail.
In Unit 12 of The Physics Classroom Tutorialthe mechanism of energy transport by an electromagnetic wave was briefly discussed. Here we will look at this method in more detail. An electromagnetic wave i.
This value is the speed of light in a vacuum. When the wave impinges upon a particle of matter, the energy is absorbed and sets electrons within the atoms into vibrational motion. If the frequency of the electromagnetic wave does not match the resonant frequency of vibration of the electronthen the energy is reemitted in the form of an electromagnetic wave.
Relationship between density and refractive index of inorganic solids
This new electromagnetic wave has the same frequency as the original wave and it too will travel at a speed of c through the empty space between atoms. The newly emitted light wave continues to move through the interatomic space until it impinges upon a neighboring particle. The energy is absorbed by this new particle and sets the electrons of its atoms into vibration motion. And once more, if there is no match between the frequency of the electromagnetic wave and the resonant frequency of the electron, the energy is reemitted in the form of a new electromagnetic wave.
The cycle of absorption and reemission continues as the energy is transported from particle to particle through the bulk of a medium.
Relationship between density and refractive index of inorganic solids - IOPscience
Every photon bundle of electromagnetic energy travels between the interatomic void at a speed of c; yet time delay involved in the process of being absorbed and reemitted by the atoms of the material lowers the net speed of transport from one end of the medium to the other.
Optical Density and the Index of Refraction Like any wave, the speed of a light wave is dependent upon the properties of the medium. In the case of an electromagnetic wave, the speed of the wave depends upon the optical density of that material. The optical density of a medium is not the same as its physical density.