Rotationsdiffraktion

Rotationsdiffraktion is a term used in optics to describe a rotation observed in a diffraction pattern that arises when the diffracting element or the incident beam introduces rotational effects. It is discussed in some German-language sources as a way to address how orientation, angular momentum, and rotational dynamics influence diffraction beyond the usual redistribution of light into diffraction orders.

The underlying idea is that diffraction can depend on orientation and angular properties. If the diffracting structure is rotated, if the beam carries orbital angular momentum, or if the interaction involves chiral or anisotropic materials, the resulting field can exhibit a rotated intensity distribution or phase front. In practice, the observed rotation may reflect the rotation angle of the element, the beam’s angular momentum, or time-dependent orientation in a rotating setup.

Experimentally, rotationsdiffraktion can be studied by using rotating diffraction gratings, spiral phase plates, or beams with orbital angular momentum interacting with rotating or anisotropic media. Detecting a rotated diffraction pattern or a rotated phase structure as a function of the element’s orientation provides information about angular momentum transfer, symmetry properties, and the coupling between rotation and diffraction.

Relation to other concepts includes the standard theory of diffraction, the rotational Doppler effect, and spin–orbit interactions of light. Understanding rotationsdiffraktion contributes to optical metrology, beam shaping, and the study of angular momentum in light-matter interactions. See also diffraction, angular momentum of light, and rotational Doppler effects.