Question

In this class, we have treated the index of refraction of materials as a constant number. However, real materials exhibit a phenomenon called dispersion, which means that the index of refraction depends on the wavelength of light propagating in the material. This is the reason that a glass prism separates white light into different colors and why water droplets form rainbows.

Consider a prism made of Glass X, a fictional material that has index of refraction n_red 1.7 for red light and n_violet 1.8 for violet light.

(a) Which color light, red or violet, travels faster in Glass X?

(b) Suppose light of both colors is incident on an interface between vacuum and Glass X at incident angle 30°. Which color light has a larger angle of refraction?

Answer 1