Laser light is shone though a single adjustable slit and the resulting diffraction pattern is viewed on the wall or projection screen.

Use optical rail to constrain beam trajectory. Align as needed. More optical components can be found in B2 and on shelves nearby this demo. Light sources of different wavelengths can be used to show how spacing depends on wavelength. If you want to be fancy, the beams can be combined using a beamsplitter and some mirrors (see 211 setup for saturation spectroscopy) and sent through the same slit to show this better.

L0, L1

PIRA DCS 6C10.10