Posted by
**anonymous** on
.

Why is white light separated into a spectrum of colors when it is passed through a diffraction grating?

The diffraction angle (theta) is given by

n x (lambda) = d sine(theta)

where

lambda = wavelength

theta = diffraction angle

d = grating spacing

n = order (1,2,3 etc.)

so each wavelength is diffracted through a slightly different angle. If the incident light is white light then you will see a rainbow at each value of n.