Abstract: One embodiment of an axial rotary joint having rotary transmission lines for the bi-directional propagation of radio frequency electromagnetic waves and light waves across a rotary interface. Each section is capable of fully independent rotation about a common longitudinal axis. The radio frequency rotary transmission line comprises waveguide tubing at each end that transitions to a coax transmission line at the rotary interface. The waveguide tubing also functions as the axial support structure. The second transmission line for light wave propagation is fully integrated into the waveguide-to-coax transition and the inner coaxial conductor, and uses optical coupling devices to form an optical coupling path across the rotary interface. This embodiment of the rotary joint can be sealed and pressurized to minimize contamination of the optics and to increase the electromagnetic wave power handling.