can we change refractive index of any material , if yes, how? and if no please tell me why?

Question

The inspiration for this question was to know whether we could work for INVISIBILITY

Answer 1

let see when you ask this question you must know that the refractive index is not constant for all the wavelength ..........ie refractive index of prism for red and blue light is different............so it not really characterstics of the material but certainly it is constat for perticular wave length............now assumeing you are talking for a perticular wavelength........then it is posible to answer your question................lets see in order to change the refractive index of any material .........bacically you have to change the speed of light in that material............for this is is necessary that your material should interact differently with the photon of same energy under different conditions..............for this it is possible to use come materials where the electron concentration or plasamon frequency changes as a function of temperature of pressure............or undergose some structural phase transformation..........with increasing or decreasing pressure or temperature..............but such materials are need to be design .................this field have lots of applications in night vesion detectors

Answer 2

Refractive index is the ratio of the speed of light in vacuum to the phase velocity of light in a given material (not vice versa, as someone wrote before). So your question becomes can we change the speed of light through amterial, and the answer is yes. Most any material can be 'doped' - or infused - with a small (or large) number of atoms or ions (and often single protons) of a different substance that bind onto the existing lattice structure and create more (or less) "light resistance", which is simply the friction light experiences as it travels through a material.

Suppose you have Lithium Niobate (n~2.25 @ room temperature), then you dope it with 0.1% Magnesium ions to generate Mag doped LiNbO3 (Mg:LiNbO3, n~2.47 @ room temperature). Doping has effectively increased the refractive index by 0.22, although the lithium niobate is still lithium niobate and still exhibits the same properties as non-Mag doped LiNbO3.

Refractive index is also a strong function of temperature (according to what is known as the Sellmeier equation, each material has it's own index vs. temp relationship). So changing the temperature of a crystal will also change it's refractive index for a given wavelength.

So the answer to your question is "Yes", for multiple reasons and in various ways it can be done.

Answer 3

Right on ,
Refractive index comes from the change in the speed of light when it comes into a different medium (like glass)
this change is fixed for a particular frequency of light and material
So we cant change it.
If we cant change it we would surely be invisible

Answer 4

The refractive index of any material is the ratio of speed of light in the medium to the speed of light in vacuum.

It is a constant for that material and it differs for various frequencies of incident light wave.

That it is a constnt for that materialal for a constant frequency.

Answer 5

i have think about this.
the major pont is to work with quantum physics
if u can prepare that type of atoms that they dont reflect photons
for this u have to creat electrons that they dont get energized by photon and get to next energy level
for this u have to make such a cver for our body
becoz we cant change the properties of carbon nitrogen etc. from which our body is made of(as far as i know)

Answer 6

we cant change the refractive index of a matreial bec. it depend on the type of the matre and we cant change the type pf the matreial

Answer 7

Make the material denser.