For demonstrating the principle of the diffraction grating and the way in which its properties are dependent upon the number of lines per unit length.
· Comprises of a card mount 90 x 40mm approximately with three 16 x 9mm apertures, each containing a diffraction grating replica.
· The grating are of 100 lines/mm, 300 lines/mm and 600 lines/mm respectively and protected cover glasses.