Under general conditions, fiber patch cables are not allowed to be bent beyond bend radius in case of light leaking. However, when installing cables at high-density environments, cable bending is hard to avoid. In order to solve the problem, bend insensitive fiber patch cable is designed to cause much lower optical power loss under bend conditions. In this way, cable bending won’t be an obstacle for your cable installation. This post will take you to explore the world of bend insensitive fiber patch cables.
Introduction to Bend Radius
Bend radius is the minimum radius one can bend a pipe, tube, sheet, cable or hose without kinking it, damaging it, or shortening its life. The smaller the bend radius, the greater is the material flexibility. When you install the cables, keep in mind do not exceed the cable bend radius. Usually, if no specific recommendations are available from the cable manufacturer, the cable bend radius should be smaller than 20 times the cable outside diameter when pulling the cable and 10 times the outside diameter when lashed in place. For example, while pulling a 2mm diameter cable allows for a 40mm sweep. When lashed in place make sure it’s a 20mm sweep. For most of today’s fiber patch cables, the bend radius is 30 mm.
Multimode Bend Insensitive Fiber Patch Cable
Our multimode bend insensitive fiber patch cables have a minimum bend radius of 7.5mm, which compares very favorably to the 30mm bend radius traditionally specified. To achieve this, an optical “trench” is added to the cladding area outside of the fiber core. This trench retains more of the light that would have escaped the core of a traditional multimode fiber. Requirements for a tighter bend radius have been developed based primarily on factors in the fiber to the home (FTTH) market. However, the benefits for premise markets have rapidly become apparent, particularly in data centers where more and more fibers are being installed in smaller areas. The expectation is that this new feature can enable deployment of multimode fibers in higher densities.
Single-mode Bend Insensitive Fiber Patch Cable
Single-mode bend insensitive fiber patch cables have been commercially available for several years. ITU recommendation G.657 specifies two classes of single-mode bend insensitive fiber patch cables: G.657 A and G.657 B. Each category (A and B) is then divided into two sub-categories: G.
657.A1, G.657.A2 and G.657.B1, G.657.B2. The minimum bend radius of G.657.A1 fibers is 10 mm, of the G.657.A2 and G.657.B1 fibers is 7.5 mm and of the G.657.B2 fibers is 5 mm. Among, ITU-T G.657.A1 and ITU-T G.657.A2 fibers are fully compliant with ITU-T G.652.D fibers. Compared with minimum bend radius of the standard single-mode G652 fibers, which is usually 30 mm, G.657 single-mode bend insensitive fiber patch cables are much more flexible thus can be confidently installed with a variety of installation methods and in the increasingly high-density application spaces of today’s data center.
If you want to be bent-free for cable installation, bend insensitive fiber optic cable is a perfect solution. Its solid trench helps reduce the cable bending optical loss. And this type of cable is as qualified and functional as the standard patch cables. Both multimode and single-mode fibers can be made bend-insensitive. A wide range of bend insensitive patch cord selections is waiting for you to choose.