LC fiber connector definition
LC (Lucent Connector) is a miniaturized fiber optic connectors developed by Bell Labs. It uses a 1.25mm ceramic ferrule and is only half the size of a traditional SC FC connector. It belongs to the high-density wiring (SFF) standard.

LC fiber optic connector characteristics
Miniaturized design: 1.25mm ferrule diameter (SC is 2.5mm), saving 50% space than SC connector, suitable for high-density rack deployment.
Modular latch: Adopts RJ-45-style buckle structure, supports quick plug-in and pull-out, and has an anti-accidental touch design.
LC connector specification
Insertion loss: 0.10–0.20dB (better than SC’s 0.25–0.3dB).
Return loss: -55dB (UPC) or -65dB (APC).
Duplex configuration: Can be installed side by side, supports dual-fiber transmission (such as TX/RX).
Main application scenarios

40G/100G optical module interconnection, compatible with high-bandwidth interfaces such as QSFP+/CFP2.
Comparison of technical advantages
Item | LC connectors | SC connectors |
Insert size | 1.25mm (high density) | 2.5mm (traditional size) |
Insert method | Snap-on (RJ-45 mechanism) | Push-pull (square interface) |
Typical loss | 0.10–0.20dB | 0.25–0.3dB |

LC fibre connector types
- LC PC fiber connector: gray/aqua/violet/rose red/green housing, flat polishing, universal multimode connection.
- LC UPC fiber connector: blue housing, flat polishing, universal single mode fiber LC connector connection.
- LC APC fiber connector: green housing, 8°bevel polishing, dedicated to high return loss scenarios (such as CATV).
- LC simplex connector: single LC connector with one ferrule, usually are LC fiber pigtails
- LC duplex connector: integrated dual ferrules, supports bidirectional transmission (such as BiDi optical modules).
Market position
LC has become the mainstream choice for data centers and 5G networks due to its miniaturization, low loss and high reliability, with a global market share of over 40% (2025 data). In the future, in CPO (co-packaged optics) technology, LC and MPO will jointly support 800G/1.6T optical interconnection.
FAQ
How to install LC fiber connectors properly?
Please below video of how to plug in the LC connectors into the LC duplex adapter.
What is the life of an LC connector?
The plugging and unplugging life of a standard fiber optic connector is generally greater than 1,000 times, determined by the mechanical wear of the components. This data applies to conventional LC style connector.
Methods to extend the life of LC style connectors
Please properly store fiber LC connectors, regularly check the LC bulkhead connector status, avoid frequent plugging and unplugging, and use appropriate dust caps,etc
What is difference between LC and sc connector?
The LC connector fiber is half the size of the SC fiber connectors. Generally, the fiber optic LC connector can be used wherever the SC connector fiber can be used. However, the appropriate fiber connector should be selected according to the actual application scenario. For more information, please refer to the article: What is difference of LC and sc connector?
How many LC type fiber connector on market?
LC Type connector can be simplex, duplex, quad, with different cable diameter 0.9mm, 2,0mm, 2.0mm, 3.5mm, 5mm, etc.