How can frequency be used to calculate refractive index?

In summary: So if you have n(λ) in air, you can calculate the velocity in air.In summary, calculating the refractive index with only the frequency of light entering the medium from air is not possible unless you have a formula that relates the index of refraction to frequency or wavelength. Additionally, if the index of refraction varies with wavelength, there will also be absorption.
  • #1
Francy
2
0
How can i calculate the refractive index knowing only the frequency of the light entering the medium from air?

n(refractive index) = (speed of light in vacuum) / (speed of light in medium)
 
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  • #2
You can't, unless you are provided with a formula for the refractive index in terms of frequency or wavelength.

p.s. Welcome to Physics Forums.
 
Last edited:
  • #3
Yeah, I think the problem I have here doesn't have all the information. Thanks anyway! Thanks also for welcoming me here ^^
 
  • #4
I believe that for real indexes of refraction, Re (n(λ)) = c/v(λ).

If the index of refraction varies with wavelength (dispersion), then there is absorption as well as dispersion, which is equivalent to a complex index of refraction. See http://en.wikipedia.org/wiki/Refractive_index
See in particular the section on Complex index of refraction and absorption.
 
  • #5
Bob S said:
I believe that for real indexes of refraction, Re (n(λ)) = c/v(λ).
But in this situation we don't have v(λ), we only have the frequency [itex]\nu[/itex]. From that we can get λ in air, but not λ in the medium or v(λ) for that matter.
 
  • #6
Redbelly98 said:
But in this situation we don't have v(λ), we only have the frequency [itex]\nu[/itex]. From that we can get λ in air, but not λ in the medium or v(λ) for that matter.
I should have said for ANY n(λ), the velocity v(λ) = c/Re (n(λ))
 

What is refractive index and why is it important?

Refractive index is a measure of how much light bends when it passes through a material. It is important because it helps scientists and engineers understand the properties of different materials and how they interact with light.

How is refractive index calculated?

Refractive index is calculated by dividing the speed of light in a vacuum by the speed of light in the material. This ratio is known as the refractive index and is typically represented by the symbol "n".

What factors can affect the refractive index of a material?

The refractive index of a material can be affected by factors such as temperature, pressure, and the wavelength of light passing through it. Additionally, the chemical composition and structure of the material can also impact its refractive index.

What are some common methods for measuring refractive index?

Some common methods for measuring refractive index include using a refractometer, a spectrophotometer, or a polarimeter. These instruments use different principles to determine the refractive index of a material, such as measuring the angle of light refraction or the amount of light absorbed by the material.

How is refractive index used in practical applications?

Refractive index is used in a variety of practical applications, such as designing lenses for eyeglasses, determining the purity of substances in chemistry, and creating optical fibers for telecommunication. It is also used in industries like cosmetics, where refractive index is used to measure the clarity and quality of products.

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