Development of a Multichannel Fiber Optic Rotary Joint Using Spatial Division Multiplexing

This paper presents the development of an alternative to the traditional multichannel Fiber Optic Rotary Joint (FORJ) using spatial division multiplexing. The proposed solution utilizes phase plates assembly in a compact housing made by a French optical communications company called Cailabs. It is distinguished from conventional multichannel technologies that rely on Dove prisms or wavelength multiplexing by using the housing of a single channel Fiber Optic Rotary Joint (FORJ) without needing strong constraint on the choice of optical transceivers. Our research focused on characterizing the specific mechanical parameters required to transfer optical modes from the rotor to the stator without deformation or misalignment of those. Three test campaigns were conducted, each with iterative improvements. The latest results demonstrate commercially viable performance for transmission of 3G-SDI video stream on up to 6 channels.