Measuring Wavelengths with LEGO® Bricks: Building a Michelson Interferometer for Quantitative Experiments

The Michelson interferometer is one of the key experiments in modern physics when it comes to the topic of interference (Box 1). Experiments using interferometry have a high historic relevance as well as uses in current areas of research (quantum erasers, gravitational wave detection) and are used in higher education. Because of the high cost of commercial experimental sets (e.g., by Thorlabs, 3B Scientific, or PASCO), they are however not widely used in schools and are only used—if at all—in demonstration experiments. Alternatively there are several variations that have a more favorable pricing range and are still usable in experiments by students. These include a Michelson interferometer realized for example through modeling clay and microscope slides or through LEGO® bricks that can be used for a qualitative approach to interference phenomena. In addition to these variants, there are also few in favorable pricing ranges that can be used to generate quantitative experimental data.