Optical signal transmission system and method for rotary joints

An optical signal transmission system for rotary joints comprising:

• a hollow cylindrical rotor, a hollow cylindrical stator connected with the rotor through a bearing, a plurality of sets of photodetectors and conditioning circuits components arranged on inner surfaces of the rotor and the stator respectively, the rotor and stator each have trays which include a plurality of optical signal sources and a beam splitter along with hollow cones and condenser lenses to provide two sets of identical beam-condensing light paths;
• the rotor and the stator are arranged opposite to each other, a closed cylindrical space is formed by the inner surfaces of the two, and an optical signal transmission space is formed by the opposing surfaces of the two trays fixed in the inner space of the rotor and the stator respectively and the cylindrical side walls of the stator and the rotor;
• the beam-condensing light paths are arranged in a center of a side of either tray facing the other tray, the two sets of beam-condensing light paths are symmetric about a certain circular cross-section in the optical signal transmission space;
• the optical signal sources and the beam splitters are arranged at a center of the other surface of the trays on the opposite side to the surface provided with the beam-focusing optical path structure, each of the beam splitters is fixedly connected to the trays, optical signals emitted by the optical signal sources on either tray are combined into a light beam by the beam splitter arranged on the tray, and then the beam is condensed by the condenser lens to obtain a hollow beam which is received by the corresponding photodetector and the corresponding conditioning circuit after being reflected from an outer surface of the hollow cone on the other tray;
• wherein each of the hollow cones is a metastructure, which has a metal-coated outer surface with high reflectivity and a blackening-treated inner surface;
• each of the hollow cones is connected to each of the trays with an opening arranged respectively at its top and bottom, and its central axis and an central axis of each of the condenser lens fixed on the opening of its top are on a same straight line.