What is a fiber optic jumper? What are the types and differences?

Optical fiber jumper (also known as optical fiber connector) refers that both ends of the optical cable are equipped with connector plugs to realize the flexible connection of the optical path.

Optical fiber cables with a plug at one end are called fiber optic pigtail cables. Optical fiber jumper, Optical Fiber Patch Cord/Cable is similar to coaxial cable, except that there is no mesh shielding layer. Its center is the glass core through which light propagates. In a multimode fiber, the diameter of the core is 50μm to 65μm, which is roughly equivalent to the thickness of a human hair. The single-mode fiber core has a diameter of 8 μm to 10 μm. The core is surrounded by a glass envelope with a lower refractive index than the core to keep the optical fiber in the core. On the outside is a thin plastic jacket to protect the envelope.

Commonly used types of optical fiber jumpers

LC optical fiber jumper: developed by BELL Research Institute. The connector is similar to SC but is smaller than SC. It adopts a modular jack latch that is easy to operate. The size of the pin and sleeve is 1.25mm, which is half of the size used by ordinary SC and FC. It connects SFP optical modules, often is used in routers and can increase the density of optical fiber connectors in optical fiber distribution frames to a certain extent.

SC patch cord: It is developed by the Japan NTT company and the structure and size of its pin and coupling sleeve are exactly the same as FC type. It adopts the standard square connector and the fastening method of the plug-in latch type lock which does not need to be rotated. It is often used as the connector of the GBIC optical module and is widely used on the router. It has the characteristics of low price and low fluctuation of access loss. It is commonly used for 100G BASE-FX connections.

FC optical fiber jumper: It was first developed by NTT of Japan. FC is the abbreviation of English Ferrule Connector. The outer protective cover of the optical fiber jumper is a metal sleeve and its fastening method is a turnbuckle. Generally, it is used on the ODF side and mostly used on the distribution frames. It has the advantages of strong tightness and dust resistance.

ST optical fiber jumper: its shell is round, the fastening method is a turnbuckle, the core is exposed, and the plug is fixed by a bayonet after half rotation. It is often used as a 10BASE-F connector and is mostly used for optical fiber distribution frames.

The MPO (Multi-fiber Push On) optical fiber jumper connector is one of the MT series connectors. The two guide holes and pins (also called PIN pins) with a diameter of 0.7mm on the left and right sides of the ferrule end can accurately connect. Various forms of MPO jumpers can be produced after processing the MPO connectors and optical fiber cables.

The difference between single-mode and multi-mode optical fiber jumpers

The concept of single-mode and multi-mode is to classify optical fibers according to their propagation mode—the concept of propagation mode of multi-mode optical fiber and single-mode optical fiber.

In the field of optical fiber data transmission, the term "mode" is used to describe the propagation mode of optical signals in the fibreglass core, that is, the mode is the propagation path of the light.

Therefore, in a single-mode fiber, light travels along one path while in multi-mode fiber, light travels in multiple paths.

1. Appearance: the sheath of single-mode optical fiber jumpers is generally yellow while multi-mode is generally orange or so-called aqua (the color between blue and green). In terms of core diameter, multi-mode fiber, under normal circumstances, should be slightly thicker.

2. Transmission distance: the transmission distance of single-mode optical fiber is not less than 5km, which is generally used for long-distance communication while multimode optical fiber can only reach about 2km, which is suitable for short-distance communication in buildings or campuses.

3. In terms of light source: because the LED light source is relatively dispersed and can produce light of multiple modes, it is mostly used for multi-mode fiber while the laser light source is close to a single mode, so it is usually used for single-mode fiber.

Bandwidth: single-mode optical fiber jumpers have a higher bandwidth than multi-mode optical fiber (as I said before, bandwidth refers to the frequency at which data is sent, so the adjective "higher" is used).

Use cost: multi-mode optical fiber allows multiple optical modes to pass, so multimode optical fiber is more expensive than single-mode ones.

However, single-mode optical fiber uses solid-state laser diodes as the light source, which is far more expensive than the light source equipment of multi-mode optical fiber, so the use cost of single-mode optical fiber is much higher than that of multi-mode optical fiber.