Observing the normal Zeeman effect in transverse and longitudinal configuration - spectroscopy using a Fabry-Perot etalon

In the experiment P6.2.7.3, the Zeeman effect is observed at the red cadmium line perpendicular and parallel to the magnetic field, and the polarization state of the individual Zeeman components is determined. The observations are explained on the basis of the radiating characteristic of dipole radiation. The so-called π component corresponds to a Hertzian dipole oscillating parallel to the magnetic field, i.e. it cannot be observed parallel to the magnetic field and radiates linearly polarized light perpendicular to the magnetic field. Each of the two σ components corresponds to two dipoles oscillating perpendicular to each other with a phase differential of 90°. They radiate circularly polarized light in the direction of the magnetic field and linearly polarized light parallel to it.