Can Multimode Fiber Jumpers be Installed in Single-mode Fiber Modules?

In recent years, from our observation, fiber optic jumpers are sure to replace copper wires. This is mainly due to their bandwidth and transmission distance. They can reach a distance of 160 kilometers and can support network backbone.

Single-mode and multimode fiber optic jumpers

Fiber optic jumpers are similar to copper wires. The main difference is that fiber optic jumpers do not transmit electrical pulses but instead transmit light, which is then converted into electrical input by optical equipment.

This works with the help of optical transmitters at both ends. The transmitter and receiver are called optical modules, which receive electrical input from the network equipment, process it and convert it into equivalent optical signals. The optical module uses LED or VCSEL to drive light along the jumper to the other end, where another optical module receives the light and converts it into equivalent electrical signals.

In multimode fibers, light in the near-infrared state is usually 850nm when transmitted over short distances and 1310nm when transmitted over long distances. In single-mode fibers, short-distance light is usually 1310nm and long-distance light is 1550nm.

Single-mode fiber jumper is a single optical glass fiber with a diameter of 8.3 to 10 microns. Therefore, compared with multimode fibers, the light is narrower and the bandwidth is higher. The single-mode optical wave is narrower and eliminates any distortion during transmission.

The core of multimode fiber is larger than that of single-mode fiber, ranging from 50 to 100 microns. Its light volume is larger, so light waves scatter in many ways when passing through the jumper. For short distances, this will not be a problem, but over distances greater than 1 kilometer, this may cause optical distortion at the far end, resulting in incomplete data transmission.

What if you need to connect a multimode and a single-mode fiber optic jumper?

Even if you can install multimode on a single-mode optical module, it is strongly recommended to use compatible equipment. When attempting to confuse installation, it is strongly recommended to pay attention to the specifications of the equipment, which can be found in the data sheet of the equipment.

The main thing to remember when installing multimode fiber on a single-mode is to use a mode-conditioning jumper. The fiber optic jumper is designed and developed to provide a convenient way to connect multimode jumpers to 1000BASE-LX optical modules. Mode-conditioning jumpers provide options for calibrating multimode fiber with single-mode single-fiber optical modules. They are built as duplex jumpers, so no other components are required.

The default feature of the 1000BASE-LX optical module requires such a jumper to emit 1310nm light along a single fiber. If a mode-conditioning jumper is not used and a regular multimode fiber is used in conjunction with a single-mode optical module, the single-mode optical module will emit light directly at the center of the jumper, causing multiple optical signals and making the receiving optical module fail.

The mode-conditioning jumper eliminates this problem and allows the single-mode emission to deviate from the center of the multimode fiber. The solution provided for emission is similar to a typical LED emission. Although the multimode fiber can be installed on a single-mode optical module, it is impossible to emit into a 9-micron fiber because the light wave of the multimode optical module is larger (usually 62.5 microns). This will result in at least 85% light loss.

The main things to keep in mind when using these types of fiber optic jumpers are:

• Mode-conditioning jumpers require MC jumpers to be connected on each side of the installation.

  
  

• When using equipment equipped with LC or SC connectors, remember that the single-mode part of the jumper must be connected to the sending side of the equipment and the multimode part of the jumper must be connected to the receiving side of the equipment.