Rami Arieli: "The Laser Adventure"

Rami Arieli: "The Laser Adventure" Chapter 1.1.2 page 3

Example 1.1:Wavelength in Matter
The velocity of Red light (l₀= 0.6 [mm]) in a certain medium is 1.5*10⁸ [m/s].
What is the wavelength of this light in this material?

Solution to example 1.1:
First find the index of refraction:

Using n, calculate the wavelength in the material:

Conclusion: The wavelength of Red light in a material with an index of refraction of 2.0, is 0.3 [mm]