Optical-fiber ribbon with spaced optical-fiber units

An optical-fiber ribbon, comprising:

• (i) a plurality n of respectively adjacent optical fibers extending in a longitudinal direction and arranged in parallel to form an optical-fiber assembly having a width w extending crosswise to a longitudinal length of the optical-fiber assembly, wherein the n optical fibers have the same nominal diameter d of between 180 microns and 200 microns, wherein the n optical fibers are uniformly distributed into a plurality U of respectively adjacent optical-fiber units whereby each of the U optical-fiber units has the same number un of optical fibers, and wherein adjacent optical fibers within each optical-fiber unit are respectively substantially contiguous to one another;
• and
• (ii) bonding material on the optical-fiber assembly adhesively bonding adjacent optical-fiber units and the corresponding adjacent optical fibers in the optical-fiber assembly, wherein each adjacent pair of optical-fiber units is separated by a longitudinal adhesive-free spacing for a respective portion of the optical-fiber assembly's longitudinal length, the respective longitudinal adhesive-free spacings having a mean gap width Savg, wherein:
• Savg≥(0.5·n·(d250−d))÷(U−1), where d250 is 250 microns, the nominal width of a conventional optical fiber.