Joseph von Fraunhofer, the investigator of the solar lines, invented the diffraction grating in 1821. This optical element showed a much higher dispersion than any glass prism and allowed Fraunhofer to investigate the solar spectrum in a resolution much better than ever seen before.

Enormous quality improvement as well as optimization of the manufacturing technique of ruled gratings are the results of Henry Rowlands efforts in development of diffraction gratings. His gratings were used worldwide and were unbeaten in quality and resolution for decades. Nowadays holographic techniques using the interference of laser beams allow manufacturing gratings with larger grating constants and bigger size.

The experiment comprises transmission gratings of different grating constants (lines per cm) a green laser with known wavelength of 532 nm and an energy saver lamp emitting a variety of different spectral lines. The resulting interference pattern is imaged on a white screen with mm scale. Applying gratings with different parameter the resolution power is demonstrated. By using a mesh like two-dimensional grating impressive patterns of light spots are created and the analogy to the principles of x-ray diffraction on crystal lattices or atomic layers demonstrated.