- #1
LmdL
- 73
- 1
Hello,
As we all know, speed of light of different wavelengths (let's say red and blue) in vacuum is same. However, in medium (like glass) it's different and depends on a wavelength and a refractive index.
Let's say we send a short pulse of white light incident into a piece of glass (of length L). Red light will come out of it first and a blue last. But how can I calculate the time difference (or a displacement) of red and blue light at the exit from the glass?
I know the velocity in medium is v=c/n, where c is constant (speed of light in vacuum) and n is a refractive index of the medium. But how can I get a relation between v (speed of light in medium) and its wavelength? I guess I need to connect between refractive index n and a wavelength of the light first. Thought to use a Cauchy's equation (or a Sellmeier equation), but maybe there is a easier way?
Thanks!
As we all know, speed of light of different wavelengths (let's say red and blue) in vacuum is same. However, in medium (like glass) it's different and depends on a wavelength and a refractive index.
Let's say we send a short pulse of white light incident into a piece of glass (of length L). Red light will come out of it first and a blue last. But how can I calculate the time difference (or a displacement) of red and blue light at the exit from the glass?
I know the velocity in medium is v=c/n, where c is constant (speed of light in vacuum) and n is a refractive index of the medium. But how can I get a relation between v (speed of light in medium) and its wavelength? I guess I need to connect between refractive index n and a wavelength of the light first. Thought to use a Cauchy's equation (or a Sellmeier equation), but maybe there is a easier way?
Thanks!