Diffraction Grating and Helium-Neon Laser

While directing the 632.8 nm red beam of a helium-neon laser through a 600 lines/mm diffraction grating, a cloud was formed using liquid nitrogen. You can see the direct beam plus the first and second orders of the diffraction.

Another way to visualize the diffraction is to take a time exposure while sweeping a ground glass through the beams. This "paints in" the beams of the diffracted laser light.