Light path along a circular arc and transmission of a signal between two units rotating relative to each other

Optical device comprising a light path for guiding a light beam along a circular arc,

• wherein the light path comprises at least one light path segment comprising a number of light path elements arranged tangentially along the light path, each of the light path elements being at least partially limited in a radial direction by a first interface,
• wherein the first interfaces of a respective light path segment are each configured to reflect at least light incident from the light path at an angle of incidence greater than a predetermined angle onto the respective first interface to keep a light beam propagating along the light path in a direction of travel predetermined for the respective light path segment on the light path;
• and
• wherein a first tangential end of the first interfaces is spaced radially further apart from the center of the circle of the circular arc than a second tangential end.