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What are LC Fiber Optic Connectors?

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LC fiber connectors are as popular as SC fiber connectors in fiber optic connectivity solutions. Here you can get good idea about the basis of lc connectors from beginner to expert. ( To learn SC Fiber Connectors you can view here )

What is LC Connector?

LC (Lucent Connector) fiber optic connectors are popular in fiber optic networking for their high-density and reliable performance. Designed by Lucent Technologies, LC connectors have become a standard due to their small form factor and ease of use. They feature a ferrule with a diameter of 1.25mm and utilize a push-pull mechanism for connection, making them a compact and efficient choice for modern optical networks.

8 types of common used LC fiber optic connectors

Types of LC Connectors

  • Standard LC Connectors: The most common type, used in a wide range of applications.
  • Uniboot LC Connectors: Combine two fibers in a single connector body and boot, reducing cable bulk.
  • APC LC Connectors: Feature an angled physical contact polish on the ferrule, minimizing back reflection and enhancing signal quality.

You can also categorized LC fiber connectors via fiber types and polishing types for LC fiber assemblies.

LC fiber connectors with different colors
Fiber TypePolishing TypeDescription
Single-modePC (Physical Contact)Features a slight curvature for better core-to-core alignment, minimizing insertion loss. Common for basic single-mode applications.
Single-modeUPC (Ultra Physical Contact)Has a more refined finish than PC, offering lower back reflection (higher return loss), suitable for higher-quality single-mode applications.
Single-modeAPC (Angled Physical Contact)Features an 8-degree angle polish for significantly lower back reflection, ideal for high-bandwidth and long-distance single-mode applications.
MultimodePC (Physical Contact)Common for general multimode applications, where alignment and lower insertion loss are essential.
MultimodeUPC (Ultra Physical Contact)Although less common in multimode than in single-mode, UPC offers improved performance in certain multimode contexts, like in data centers or high-speed LANs.
APC (Angled Physical Contact)Typically not used in multimode applications due to multimode fiber’s inherent modal dispersion and less concern over back reflection.
LC Fiber Connectors for Assemblies

Key Parameters of LC Fiber Connectors

  • Insertion Loss: Ideally, LC connectors should have a low insertion loss, typically less than 0.3 dB.
  • Return Loss: For standard PC polish, a return loss of >50 dB is common, whereas APC connectors can achieve >60 dB.
  • Durability: The connectors should withstand hundreds of mating cycles without significant performance degradation.
  • Operating Temperature: LC connectors should function across a wide temperature range, usually from -40°C to +75°C.

How to Use LC Fiber Connectors?

LC connectors are straightforward to use. They connect to LC adapter panels and equipment interfaces by simply inserting the connector until it clicks into place. To disconnect, pull back on the connector latch and pull out the connector.

Here below is a useful video for better understanding about LC connectors

Application of LC Fiber Connectors

LC connectors are versatile and used in various applications, LC Fiber Connectors are not used alone, usually, it is assemblied as LC fiber pigtails, LC fiber patch cord, or LC outdoor fiber patch cables.

including:

  1. Datacom and telecom networks
  2. High-density networking environments like data centers
  3. Fiber to the home (FTTH) applications
  4. Local Area Networks (LANs)
  5. Optical switches and routers

How to Choose LC Fiber Connectors?

Selecting the right LC connector involves considering:

  • Application requirements: Data rate, signal strength, and environmental conditions.
  • Connector type: Standard, uniboot, or APC based on space requirements and signal quality needs.
  • Compatibility: Ensure the connector matches the fiber type (single-mode or multimode) and equipment interfaces.

LC Fiber Connectors vs. SC Fiber Connectors

In order to have a general understanding about the differences from them, You can refer to the below table to have a look at their key differences.

FeatureLC ConnectorSC Connector
Ferrule Diameter1.25 mm2.5 mm
Connector TypePush-pull mechanismPush-pull mechanism
SizeSmaller, more suitable for high-density applicationsLarger, used in various applications but less dense
Insertion LossTypically <0.3 dBTypically <0.3 dB
Return LossPC: >50 dB, APC: >60 dBPC: >50 dB, APC: >60 dB
Ease of HandlingCompact design can be more challenging to handleEasier to handle due to larger size
ApplicationData centers, high-speed networks, FTTHTelecom, datacom, CATV
DurabilityDesigned for high durability and repeated matingsRobust and designed for repeated use
LC Fiber Connectors vs. SC Fiber Connectors

Conclusion

Both LC and SC connectors offer reliable performance, but the choice between them often comes down to the specific requirements of the network, including density, ease of handling, and space considerations. LC connectors are preferred in high-density environments like data centers due to their smaller size and compact nature, while SC connectors are valued for their ease of use and robustness in a wider range of telecommunication applications.