Hanle effect
Encyclopedia
The Hanle effect is a reduction in the polarisaton of light when the atoms emitting the light are subject to a magnetic field in a particular direction, and when they have themselves been excited by polarised light.
It is named after Wilhelm Hanle
, who first described it in Zeitschrift fur Physik
in 1924. Attempts to understand the phenomenon were important in the subsequent development of quantum physics.
It is named after Wilhelm Hanle
Wilhelm Hanle
Wilhelm Hanle was a German experimental physicist. He is known for the Hanle effect. During World War II, he made contributions to the German nuclear energy project, also known as the Uranium Club...
, who first described it in Zeitschrift fur Physik
Zeitschrift für Physik
The European Physical Journal is a joint publication of EDP Sciences, Springer Science+Business Media, and the Società Italiana di Fisica...
in 1924. Attempts to understand the phenomenon were important in the subsequent development of quantum physics.
Applications
- Observation of the Hanle effect on the light emitted by the sun is used to indirectly measure the magnetic fields within the sun, see:
- Polarization in astronomyPolarization in astronomyLight Polarization is an important phenomenon in astronomy. The polarization of starlight was first observed by the astronomers William Hiltner and John S. Hall in 1949. Subsequently, Jesse Greenstein and Leverett Davis, Jr...
- Imaging spectroscopyImaging spectroscopyImaging spectroscopy is similar to color photography, but each pixel acquires many bands of light intensity data from the spectrum, instead of just the three bands of the RGB color model...
- Polarization in astronomy