Crafting a Basic Michelson interferometer. There are two mirrors in the interferometer. There is a beam splitter to separate light beam, from the laser. We will be using a photodetector to measure the interference pattern created by the laser being reflected onto it. The beam is shined upon the beam splitter. The beam splitter splits the beam into two beams, one will continue onto one mirror while the other is shined upon the other mirror. The two beams reflect off the mirrors and re-shine on beam splitter. These beams that go through the beam splitter will form an interference pattern. The interference pattern will appear as circular bands and each band will represent 1 wavelength. This is because the crest of the first wave has hit the second crest of wave, causing a constructive interference. This constructive interference can be measured and the frequency can be derived from it with a simple measurement program and a photodetector.