- Sep 20, 2013
Diffraction gratings used to separate light are made up of lines on a mirrored surface or on a piece of glass or plastic that you use, sort of, like a prism to separate the light. You can get these kinds of gratings in different lines/mm. Like 300 lines per millimeter, 500 l/mm, 1200 l/mm, etc. For a loose grating used for this purpose, I prefer 1000 l/mm.