• understand what makes an optical grid work, by approaching it via “multiple slits”
• the coherent light of a laser gives the possibility of easy observation
• clear correlation of measurement results to the underlying theory

Lens holder
Lens, mounted, f +20 mm
Lens, mounted, f +100 mm
Object holder, 5×5 cm
Laser, He-Ne, 0.2/1.0 mW, 230 V AC
Optical bench expert, l = 1500 mm
Base for optical bench expert, adjustable
Slide mount for optical bench expert, h = 30 mm
Diaphragm, 3 single slits
Diaphragm, 4 multiple slits
Diffraction grating, 4 lines/mm
Diffraction grating, 8 lines/mm
Diffraction grating,10 lines/mm
Diffraction grating,50 lines/mm
Sliding device, horizontal
Si-Photodetector with Amplifier
Control Unit for Si-Photodetector
Digital multimeter 2005
Connecting cord, 32 A, 750 mm, red
Connecting cord, 32 A, 750 mm, blue
Adapter, BNC-plug/socket 4 mm

1. The position of the first intensity minimum due to a single slit is determined, and the value is used to calculate the width of the slit.
2. The intensity distribution of the diffraction patterns of a threefold, fourfold and even a fivefold slit, where the slits all have the same widths and the same distance among each other, is to be determined. The intensity relations of the central peaks are to be assessed.
3. For transmission grids with different lattice constants, the position of the peaks of several orders of diffraction is to be determined, and the found value used to calculate the wavelength of the laser light.

• Huygens principle
• Interference
• Fraunhofer und Fresnel diffraction
• Coherence