# Wavelengths in fused silica and in silicon for photons

## Homework Statement

Compute the wavelengths in fused silica and in silicon for photons whose free-space wavelengths are 800 nm, 1300 nm, and 1550 nm.

## Homework Equations

This is the problem, I'm not sure what equation to use and the textbook does not seem to say, well what little I have of the text because I was forced to take pictures from a classmate's book.

## The Attempt at a Solution

I have a feeling the equation might be ω0=(λ f)/( ∏ω) but this is under a section about Gaussian light-beams, something the problem makes no reference to anyway. I just need the equation and I can solve the rest from there.

SammyS
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## Homework Statement

Compute the wavelengths in fused silica and in silicon for photons whose free-space wavelengths are 800 nm, 1300 nm, and 1550 nm.

## Homework Equations

This is the problem, I'm not sure what equation to use and the textbook does not seem to say, well what little I have of the text because I was forced to take pictures from a classmate's book.

## The Attempt at a Solution

I have a feeling the equation might be ω0=(λ f)/( ∏ω) but this is under a section about Gaussian light-beams, something the problem makes no reference to anyway. I just need the equation and I can solve the rest from there.
Do you know the index of refraction for fused silica and silicon ?

How does the wavelength of light depend upon the index of refraction of the material that the light is passing through?