Question

The index of refraction for crown glass is 1.512 at a wavelength of 660 nm (red), whereas its index of refraction is 1.530 at a wavelength of 410 nm (violet). If both wavelengths are incident on a slab of crown glass at the same angle of incidence, 68.4degree, what is the angle of refraction for each wavelength?

Answer 1

Assuming the light starts in the air,

n air sin(theta incident) = n glass sin(theta refraction)

sin(theta refraction) = sin(theta incident)/n glass

For RED,

sin theta = sin68.4 / (1.512)

theta = 37.94 degrees

FOR VIOLET

sin theta = sin68.4 / (1.530)

theta = 37.42 degrees