1. Index of Refraction

2. Speed of Light- Is greatest in a vacuum, c = 3x108m/s
Typically decreases with increased density of
the material it travels through (medium).

3. Index of Refraction
Is a proportion of the speed of light in a vacuum relative to the speed of light for a given medium.
n=c/v
n=index of refraction
c= speed of light in a vacuum
v= speed of light in a medium

4. When light refracts the frequency of the wave is unaffected.
Because wave speed= λf, as speed decreases as does the wavelength this leads to…
n= λ/ λm

5. Practice Problem n= λ/ λm
Green light has a wavelength of 500 nm in a vacuum. Find the speed of this light and its wavelength as it travels through diamond with an index of refraction of 2.42.
n=c/v,
v = c/n = 3x108m/s / 2.42 = 1.24x108m/s
n= λ/ λm
λm= λ /n = 500 nm/2.42 = nm