Fiber Optic Patch Cord is the a fiber-optic cable capped at either end, with connectors from the equipment to the fiber optic cabling link.
It has a thicker protective layer and generally use for the connection between the optical transceiver and the terminal box.
Application of patch cord is some fields such as optical fiber communication system, optical fiber access network, optical fiber data transmission and local area network.
This blog post will introduce you what is patch cord.
The concept of Fiber Optic Patch Cord
Fiber Optic Patch Cord means that both ends of the optical cable are equipped with connector plugs to realize the active connection of the optical path.
If only one end is equipped with a plug, it is called a pigtail.
It is similar to coaxial cable, but without the mesh shield.
At the center is the glass core for light propagation.
In a multimode fiber, the diameter of the core is 50 μm to 65 μm, which is roughly equivalent to the thickness of a human hair, while the diameter of the core of a single mode fiber is 8 μm to 10 μm.
Glass jacket surround the cores with a lower refractive index than the core to keep the fiber inside the core.
On the outside is a thin plastic jacket to protect the envelope.
2.Classification of fiber optic patch cord
The SFP module can connect to an LC fiber optic connector, while the GBIC connects to an SC fiber optic connector. The following is a detailed description of several commonly used fiber optic connectors in network engineering:
①FC-type optical fiber patch cord: The external strengthening method is a metal sleeve, and the fastening method is a turnbuckle. Generally used on the ODF side (the most used on the distribution frame)
②SC-type: Connector for connecting GBIC optical module, its shell is rectangular, and the fastening method is plug-in pin-bolt type, without rotation. (Most used on router switches)
③ST-type: commonly used in optical fiber distribution frames, the shell is round, and the fastening method is a turnbuckle. (For 10Base-F connection, the connector is usually ST type. Commonly used in fiber distribution frame)
④ LC-type: a connector to connect the SFP module, which is made of an easy-to-operate modular jack (RJ) latch mechanism. (commonly used by routers)
Here are some other patch cord classification methods：
1. According to the connector : FC, ST, SC, LC, MU, MPO, E2000, MTRJ, SMA, etc. The end contact methods include PC, UPC, and APC.
2. Optical fiber outer diameter Ф0.9mm, Ф2mm, Ф3mm, number of optical fiber cores: single core, double core, 4 cores, 6 cores, 8 cores, 12 cores or customer specified.
3. Fiber types : G652B, G652D, G655, G657A1, G657A2, 50/125, 62.5/125, OM3(50/125-150), OM4(50/125-300), etc.
4. The color of the connector : blue (commonly means single-mode PC, UPC connector), beige, gray (commonly means multi-mode connector), green (APC connector), water blue (OM3), the color of the boot:
3.OM3 multimode fiber introduction
OM3 multimode optical cable is an optical cable which made of OM3 multimode optical fiber plus indoor or outdoor sheath.
It often use in the backbone laying of buildings and the backbone connection between two buildings in close proximity.
OM stands for Multi-mode fiber (Multi-mode fiber, also known as MMF),
There are usually four grades of OM1/OM2/OM3/OM4, the main difference is that the mode bandwidth of the 850nm transmission window is different.
OM2, OM3, and OM4 optical fibers belong to the A1a optical fiber specified in IEC 60793-20. A1a fiber adopts 50/125 structure, 50μm core and 125μm cladding, OM2 is A1a.1, OM3 is A1a.2, OM4 is A1a.3.
OM3 and OM4 are laser-optimized fiber types that can provide higher transmission bandwidth in the 850nm transmission window.
4.Introduction of MPO patch cord
The MPO (Multi-fiber Push On) connector is one of the MT series connectors.
The ferrules of the MT series use two guide holes with a diameter of 0.7mm on the left and right sides of the ferrule end face and guide pins (also called PIN pins) for precise connection.
MPO connectors and optical fiber cables can combine to produce various forms of MPO patch cords. MPO patch cords usually features 2~12 cores, and can be up to 24 cores. Currently, 12-core MPO connectors are most used.
The compact design of the MPO connector makes the MPO patch cord more cores and smaller in size.
MPO patch cords are widely use in environments where require high-density integrated optical fiber lines during the wiring process. Mainly as follows:
- 40/100GSFP, SFP+ and other transceiver modules
- Connections inside and outside the device