Optical rotating transmitter having a free inside diameter

The invention relates to a method for transmitting the modulation optical signal device between the first device and second unit, an installation of the first unit of the relative to the second unit can run. The device comprises a first direction of the optical waveguide is circular, orbit's for entering the optical coupling or a pair of the optical waveguide the first optical coupler, for and optical coupled with one or a pair of the optical waveguide, and arranged on the second unit, and is opposite to the guide device of the optical coupler. In turn to realize the high transmission, which a method for determining the coupling plug the optical waveguide the position control device, or a supporting hydrodynamics.