Bending Radius of Single-Mode and Multi-Mode Optical Fibers

It is well known that when installing optical fiber jumpers, attention must be paid to ensure that the cable's bending degree does not exceed its bending radius, otherwise light leakage and loss will occur, as shown in the figure below. The greater the bending degree, the greater the loss of the optical signal. Therefore, this type of optical fiber jumper is undoubtedly not suitable for high-density cabling areas in data centers. How to solve the high-density cabling problem in data centers? Bend-insensitive fiber jumpers are the ideal solution for high-density cabling, possessing excellent bending resistance while maintaining the same mechanical and optical performance as regular fiber jumpers.

What is Bending Radius?

The bending radius refers to the maximum degree of bending that a cable can maintain its normal working performance. The smaller the bending radius, the better the cable's resistance to bending. Typically, the static bending radius of a cable is 10 times the cable's outer diameter, and the dynamic bending radius is 20 times. Currently, the bending radius of ordinary fiber jumpers on the market is generally 30mm, while that of bend-insensitive fiber jumpers is much smaller, only a few millimeters. Bend-insensitive fiber jumpers mainly include bend-insensitive single-mode fiber jumpers and bend-insensitive multi-mode fiber jumpers.

Bend-Insensitive Single-Mode Fiber Jumpers

Bend-insensitive single-mode fiber jumpers, through optimized design, greatly improve their bending performance. The ITU standard G.657 now specifies two different types of bend-insensitive single-mode fiber jumpers: G.657 A and G.657 B. These two types of fiber jumpers can further be subdivided into G.657.A1, G.657.A2, G.657.B1, and G.657.B2. The minimum bending radius for G.657.A1 jumpers is 10mm, for G.657.A2 and G.657.B1 jumpers it is 7.5mm, and G.657.B2 jumpers can achieve a minimum radius of 5mm.

Compared to G652 jumpers, G.657 single-mode bend-insensitive jumpers offer more flexibility in installation and are widely used in today's data centers.

Bend-Insensitive Multi-Mode Fiber Jumpers

The minimum bending radius of bend-insensitive multi-mode fiber jumpers is 7.5mm. They feature a special optical "groove" design between the core and the cladding, which, compared to traditional multi-mode fiber jumpers, retains more light.

It's worth mentioning that the design of bend-insensitive multi-mode fiber jumpers was initially intended to meet the needs of FTTH applications. Now, bend-insensitive multi-mode fiber jumpers are increasingly used in high-density cabling areas of data centers.

As high-density applications become more prevalent, bend-insensitive fiber jumpers play an increasingly important role. We can provide a variety of bend-insensitive multi-mode fiber jumpers (OM2/OM3/OM4) and bend-insensitive single-mode fiber jumpers (OS2), which, in addition to having excellent bending resistance, also have the same mechanical and optical performance as regular fiber jumpers. Our products undergo factory testing to ensure quality, and the outer sheath material, jumper length, connector type, and color can all be customized.