The basic Michelson interferometer setup uses any kind of beam splitter to divide one beam of light into two beams, each of them back-reflected to the beam splitter and recombined and directed to the fourth arm where any kind of detector is placed. One arm of the interferometer may have a different length or contain some material under test.
Using this version of a Michelson interferometer setup, one can learn the handling, alignment, and measurement techniques of a basic interferometer system. Interferometry is a technique used to investigate optical phenomena through the creation of interference patterns (hence, "interferometer").
Further content and detailed descriptions are available to enrolled students via the course's page at the Moodle website of the Friedrich Schiller University Jena.