Fiber Optic Connector Guides

What are fiber & networking connectors?

Fiber optic connectors are unique. Fiber cables transmit pulses of light instead of electrical signals, so the terminations must be much more precise. Instead of merely allowing pins to make metal-to-metal contact, fiber optic connectors must align microscopic glass fibers perfectly in order to allow for communication. While there are many different types of fiber connectors, they share similar design characteristics. Simplex vs. duplex: Simplex means 1 connector per end while duplex means 2 connectors per end. There are three major components of a fiber connector: the ferrule, the connector body, and the coupling mechanism.

  • Ferrule: this is a thin structure (often cylindrical) that actually holds the glass fiber. It has a hollowed-out center that forms a tight grip on the fiber. Ferrules are usually made from ceramic, metal, or high-quality plastic, and typically will hold one strand of fiber.
  • Connector Body: this is a plastic or metal structure that holds the ferrule and attaches to the jacket and strengthens members of the fiber cable itself.
  • Coupling Mechanism: this is a part of the connector body that holds the connector in place when it gets attached to another device (a switch, NIC, bulkhead coupler, etc.). It may be a latch clip, a bayonet-style nut, or similar device.

An optical fiber connector terminates the end of an optical fiber, and enables quicker connection and disconnection than splicing. The connectors mechanically couple and align the cores of fibers so that light can pass. Connectors are available in APC (Angle Polished Connector) and UPC (Ultra Polished Connector) varieties.

  • No epoxy, fiber polishing, special tools or fusion splicer required
  • Quick and easy fiber termination in less than two minutes
  • Durable components design for convenience and reusability
  • Pre-installed fiber in ferrule for on-site assembly
SC Connectors SC stands for Subscriber Connector. A general purpose push/pull style connector. SC has an advantage in keyed duplexibility to support send/receive channels. Mostly used for CATV applications.scapc_stepped
FC Connectors FC stands for Fixed Connection. It is fixed by way of a threaded barrel housing. FC connectors are typical in test environments and for singlemode applications. FC connectors were designed for use in high-vibration environmentsfc
ST Connectors ST stands for Straight Tip. A quick release bayonet style connector with long ferrule. STs were predominant in the late 80s and early 90s. Common connector for mulitmode fibersst
LC Connectors LC stands for Lucent Connector. The LC is a small form-factor connector much like the SC connector but with a ferrule that is half the size. (duplex shown right) lc-duplex

Details per Connector:

LC, SC, and ST Connectors
Fiber Size/TypeInsertion Loss
Typical/Maximum (dB)
Reflectance (dB)Ferrule
62.5 µm MM0.1/0.5≤ -20Zirconia
50 µm MM0.1/0.5≤ -20Zirconia
50 µm LOMMF0.1/0.5≤ -26Zirconia
LC Connectors:
ParameterDescription
IntermateabilityConnectors are FOCIS compliant with TIA/EIA 604-10A
QualificationPassed EIA/TIA 568-B.3
Durability0.2dB change, 500 rematings, FOTP-21
Tensile Strength10 lb ≤ 0.2 dB change on jacked cable; 0.5 lb ≤  0.2 dB change on 900µm cable; FOTP-6
Operating Temp.-40° to +75°C, exceeding EIA/TIA 568-B.3
SC Connectors
ParameterDescription
IntermateabilityConnectors are FOCIS compliant with TIA/EIA 604-3
QualificationPassed EIA/TIA 568-B.3
Durability0.2dB change, 500 rematings, FOTP-21
Tensile Strength10 lb ≤ 0.2 dB change on jacked cable; 0.5 lb ≤  0.2 dB change on 900µm cable; FOTP-6
Operating Temp.-40° to +75°C, exceeding EIA/TIA 568-B.3
ST Connectors
ParameterDescription
IntermateabilityConnectors are FOCIS compliant with TIA/EIA 604-2
QualificationPassed EIA/TIA 568-B.3
Durability0.2dB change, 500 rematings, FOTP-21
Tensile Strength10 lb ≤ 0.2 dB change on jacked cable; 0.5 lb ≤  0.2 dB change on 900µm cable; FOTP-6
Operating Temp.-40° to +75°C, exceeding EIA/TIA 568-B.3

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