Fiber Optic Interface Types

[Fiber Optic Interface Types:](

FC round with thread, ST bayonet round, SC bayonet square, LC similar to SC but half the size, PC micro-spherical polishing, APC 8° angle with micro-spherical polishing, MRTJ square, one end dual-fiber transceiver (mostly used on 3com), fiber modules: generally support hot-swap, GBIC mostly uses SC or ST fiber interfaces, SFP small form-factor GBIC, uses LC type fiber, single-mode: L, wavelength 1310; single-mode long-haul LH, wavelength 1310, 1550; multi-mode: SM, wavelength 850; SX/LH indicates compatibility with both single-mode and multi-mode fiber.
Common fiber patch cord interface types are shown in the figures below:

The figure above shows LC to LC. LC is the connector type commonly used with SFP and mini GBIC on routers.

The figure above shows FC to FC, which is also one of the commonly used fiber patch cords.

FC to SC. The FC end plugs into the fiber distribution frame, and the SC end plugs into the GBIC on a Catalyst or other device.

ST to FC. For 10Base-F connections, the connector is typically ST type, and the other FC end connects to the fiber distribution frame.

SC to SC, both ends are GBIC.

SC to LC, one end GBIC, the other end MINI-GBIC.

FC round with thread (most commonly used on distribution frames)
ST bayonet round
SC bayonet square (most commonly used on routers and switches)
PC micro-spherical polishing
APC 8° angle with micro-spherical polishing
MT-RJ square, one end dual-fiber transceiver (used on Huawei 8850)
Fiber modules: generally support hot-swap
GBIC Giga Bitrate Interface Converter, mostly uses SC or ST fiber interfaces
SFP small form-factor GBIC, uses LC type fiber
Fiber types used:
Single-mode: L, wavelength 1310; single-mode long-haul LH, wavelength 1310, 1550
Multi-mode: SM, wavelength 850
SX/LH indicates compatibility with both single-mode and multi-mode fiber

In the labeling of pigtail connectors, we often see "FC/PC", "SC/PC", etc. The meanings are as follows:
The part before "/" indicates the connector type of the pigtail.
"SC" connector is a standard square connector made of engineering plastic, featuring high temperature resistance and resistance to oxidation. The optical interface on transmission equipment side generally uses SC connectors.
"LC" connector is similar in shape to SC connector but slightly smaller.
"FC" connector is a metal connector, generally used on the ODF side. Metal connectors have a higher number of insertions/withdrawals than plastic ones.

There are many connector types. In addition to the three mentioned above, there are also MTRJ, ST, MU, etc.
The part after "/" indicates the ferrule end-face finishing process, i.e., the polishing method.
"PC" is the most widely used in telecom carrier equipment, with a flat ferrule end-face.
"UPC" has lower attenuation than "PC" and is generally used in equipment with special requirements. Some foreign manufacturers use FC/UPC for internal patch cords in ODF frames, mainly to improve the specifications of the ODF equipment itself.