can we manipulate the refrective index of any object? explain your answer.
Answers
Answer:
Light interacts with a dielectric because the oscillating electric field associated with the light polarises the electron density within the dielectric, and this produces oscillating electric dipoles. These oscillating dipoles then reradiate light that interferes with the incident light and change its speed of propagation. It is the change in the strength of this interaction that causes the light to reflect at an interface.
The refractive index is related to the strength of the interaction between the light and the dielectric, so if the refractive index is the same either side of an interface that means the interaction of the light with the two materials is the same. And if the light interacts in the same way with both materials it is unaffected by passing though a boundary between them.
It might seem strange that a solid like glass and a liquid like glycerine can interact with light in the same way, but remember that the wavelength of light is much greater than the sizes of the molecules in the glass or glycerin. As far as the light is concerned both glass and glycerine are just a mass of electrons. If the interaction of the light with the electrons is the same in both glass and glycerine the light will propagate at the same speed in both of them.