Issue link: https://www.e-digitaleditions.com/i/1327492
200 µm 250 µm 200 µm 250 µm January/February/March 2021 I 39 200 µm Coated Dia. Fibers 36% reduction in cross-section 72-fiber 900 µm Tight Buffer ~20 mm 72-fiber Flat Ribbon ~10 mm 72-fiber Rollable Ribbon ~6 mm 1728-fiber Rollable Ribbon ~25 mm More fibers in smaller cables for significant increase in fiber density Rollable Ribbon Cables Advancements in Optical Fiber and Density For new fiber and cable technologies, advances are focused on downsizing and increasing density, as well as packing in more fibers or transmission lanes into a smaller space. Optical fiber and cable manufacturers are now being challenged to increase the number of fibers or to increase the amount of information that can be carried on each fiber. One way to increase fiber count is to reduce the size of the fiber, not the glass portion but the protective acrylate coating from 250 µm to 200 µm or even 180 µm diameters. This reduces the cross-sectional area by over 35 percent, which allows more fibers to be put into the same size cable. Another way of reducing cable size is with rollable or flexible ribbon, rather than having flat ribbons that stack up. These new ribbons roll up on themselves to improve packing density. The ribbon returns to its flat shape when stripping and prepping for termination, thereby simplifying fiber organization and mass fusion splicing. FIGURE 3: Rollable ribbon comparison to traditional flat ribbon SMF. The 72-fiber rollable ribbon cable takes up much less space when compared to the 72-fiber flat ribbon. In fact, a 1,728-fiber rollable ribbon cable is only 25mm in diameter, which is not much bigger than a 72-fiber type buffer cable at 20 mm. Combining 200 or 180 µm coated fiber with rollable ribbon can further increase fiber density (Figure 3). Rollable ribbon cable has been available in singlemode for several years although the cable designs continue to evolve. Several companies are now working on multimode solutions. OM5 is still a small percentage of overall use. It is expected to pick up, especially since IEEE has published the 400G SR4.2 Ethernet standard. Optical Fiber Advancements