Grating is an optical device composed of a large number of parallel slits of equal width and equal distance. There are many types of gratings. Generally, the commonly used grating is made by engraving a large number of parallel notches on the glass. The nicks are divided into opaque parts. The smooth part between the two nicks can reflect light. Realpoo Optica can make grating that has thousands to tens of thousands of grooves within the width of 1CM.
