The invention discloses a rotator. The rotator comprises a rotating body, half-wave plates and Faraday rotating plates. Both ends of the rotating body are a first light passing end and a second light passing end, the bottom surface of the rotating body is a plane, at least two grooves are formed in the rotating body, and the grooves are isolated from each other through a middle body; the half-wave plates are arranged in the grooves of the rotating body, and the included angle between the optical axes of the half-wave plates and the vertical section or the transverse section of the rotating body is 22.5 degrees; the Faraday rotating plates are arranged at the second light passing end of the rotating body. In the above way, a magnetic field is formed through formation of the grooves, the grooves, the half-wave plates and the Faraday rotating plates are combined as an independent rotating unit, and an independent rotating function can be achieved by each groove without mutual influence; meanwhile, as a whole, assembly steps are omitted, and the stability and the reliability are high.