Experiments which utilize the Hanle effect include measuring the lifetime of excited states,[3] and detecting the presence of magnetic fields.
When light interacts with this oscillator, it sets the electron in motion in the direction of its polarization.
Consequently, the radiation emitted by this moving electron is polarized in the same direction as the incident light, as explained by classical electrodynamics.
Observation of the Hanle effect on the light emitted by the Sun is used to indirectly measure the magnetic fields within the Sun, see: The effect was initially considered in the context of gasses, followed by applications to solid state physics.
Tests of zero field Stark level crossings came after the Hanle-type measurements, and are generally less common, due to the increased complexity of the experiments.