Patent ID: 7936954

Claim:
An optical rotary joint comprising as optical constituent parts: a first collimator arrangement for coupling-on first light-waveguides; a second collimator arrangement for coupling-on second light-waveguides, which is supported to be rotatable relative to the first collimator arrangement about a rotation axis; and a derotating optical element which is located in a light path between the first collimator arrangement and the second collimator arrangement; wherein an inner space of the optical rotary joint between the optical constituent parts is filled with a medium; wherein at least one of the optical constituent parts has an intermediate layer on a boundary face of the at least one of the optical constituent parts to the medium; wherein the intermediate layer has a refractive index in a range between a refractive index of an optical material of the at least one optical constituent part which is distinct from the intermediate layer and a refractive index of the medium; and wherein the intermediate layer comprises a nano-structure having individual elements with dimensions and distances from each other which are smaller than 1/10 of a wavelength of light to be transmitted through the optical rotary joint.