A Fabry-Pérot etalon for optical filtering and generation of interference rings in the anomalous Zeeman effect experiment.
The fixed etalon consists of a substrate with a highly reflective, partially reflective coating on both sides. The substrate and mirrors form an optical resonator that fulfills the resonance condition for the specific wavelength of 480 nm of the turquoise cadmium line. The tilt of the etalon to the optical axis can be adjusted with three adjustment screws in the housing, allowing the displayed pattern of interference rings to be shifted horizontally and vertically.
