Optical fiber cables for synchronous remoting of numerous transmitters/receivers

The relative fiber-to-fiber microwave phase changes induced in optical fiber cables by interfiber thermal and strain (bending-induced) gradients are reported. It is found that these changes are effectively minimized in cables where the fibers spin around the center member at a fast rate. Commercial "loose-tube" cables are found to preserve the fiber-to-fiber phases within 1/spl deg/ at modulation frequencies as high as 18 GHz. These cables appear well suited for fiber-optic remoting of numerous phase-matched transmitters and receivers.