In this lab, you can explore what light does when it encounters a diffraction grating. Use at least one of the checkboxes to turn on a beam of light. When the light encounters the diffraction grating (a comb-like structure with a large number of equally spaced openings), the light is diffracted, because of constructive interference, at particular angles. Compared to a double-slit, the lines produced by the diffraction grating are very sharp (narrow) and bright.

A close-up of the center of the grating can be seen at the bottom right. You can use the slider to control the grating spacing, which is the distance between neighboring openings in the grating.

In the simulation, red light has a wavelength of 650 nm, green light has a wavelength of 550 nm, and blue light has a wavelength of 450 nm.