Fiber Optic Patch Cable

Keyed LC Connectivity System Overview

In recent years, with the ever-increasing amount of unauthorized or inadvertent data being exchanged, IT managers are facing the challenges of maintaining data security in highly sensitive applications, such as data centers, telecommunications rooms and workstation areas. In order to respond to improve data security in high-performance networks, many physically discrete fiber connection systems have emerged. Among these systems, keyed LC connectivity system is a good choice.

Why Design Keyed Fiber Connectivity System Based on LC Technology?

All physically discrete fiber connectivity systems are based on small form factor (SFF) formats, which offers twice the density of a SC connector. LC and MT-RJ are both SFF connectors, why design keyed fiber connectivity system based on LC technology? The following part compares these two connectors in four aspects:

  • Insertion and Return Loss Characteristics—The LC connector uses a 1.25 mm ferrule that provides a proven connector-adapter-connector quality mating with excellent durability. The MT-RJ uses a single polymer ferrule on metal pins for the final alignment of the fibers. The different design makes the insertion and return loss characteristics of LC and MTRJ different. The average insertion loss and return loss from a factory installed MT-RJ is -0.3 dB and -40 dB, but for a LC is 0.2 dB and -55dB. The lower insertion loss, the better performance, while the higher return loss, the better performance. It is obvious that LC connector shows better characteristics of insertion and return loss than MT-RJ.
  • Cleaning Method—The LC connector can be cleaned using traditional fiber cleaning methods, while the MT-RJ is more difficult to clean because of the alignment pins. The pin receptacles on the female connector side can also get plugged with dirt and affect fiber alignment.
  • Design Flexibility and Polarity Reversal—LC Connector can be both simplex and duplex. The LC duplex connector is created by attaching 2 simplex connectors together with a clip. It can be easily un-assembled if the polarity of a patch cord needs to be reversed. However, the MT-RJ is a duplex connector that cannot be modified for polarity reversal.
  • Field Installation—LC connectors can be field-installed on any cable construction using the same proven field-installation method as SC and ST compatible. But the MT-RJ connector design requires 2 fibers to be installed simultaneously, negatively impacting the overall installed performance and installation yield.
Various Components in Keyed LC System

Actually, keyed LC connectivity system is a big family that contains various components, and the most common members are keyed LC connector, keyed LC fiber patch cord, keyed LC fiber optic adapter, keyed LC adapter panel and keyed LC fiber optic cassette.

Keyed LC Connector & Fiber Patch Cord

Keyed LC connector, also called as secure LC connector, is a basic component in keyed LC connectivity system. It has specific color codes and functional keyed features to identify and manage restricted network connections, ensuring the data security at the mechanical level. The keyed LC fiber patch cable terminated with keyed LC connectors should be used with the same color coded fiber adapters or fiber adapter panels, because each color represents a unique keying pattern which only allows connection when the color matches. Keyed LC fiber patch cable is frequently used in the network in single-mode 9/125 micron, multimode 62.5/125 micron and laser-optimized 50/125 micron. The following picture shows keyed LC fiber patch cable terminated with keyed LC connectors in different colors.


Keyed LC Fiber Optic Adapter

Keyed LC fiber optic adapter is keyed on both the front and back to prevent installation errors and avid a possible security breach. These components have different color coded keyed patterns for identification and rare available for both single-mode and multimode applications. Generally, keyed LC fiber optic adapters (shown below) can be used for workstation area, consolidation point or telecom room applications.


Keyed LC Adapter Panel

Keyed LC adapter panel (see in the following image) is a widely recognized modular solution for restricted fiber cross-connect systems. Application-specific networks with levels of security can be supported with keyed LC adapter panel in data center, equipment room, and telecommunications room.


Keyed LC Fiber Optic Cassette

Keyed LC fiber optic cassette (shown image below) support restricted network applications in the data center, equipment room and telecommunications room. Horizontal fiber links from keyed LC cassette in the telecommunications room extend to keyed LC outlet fittings to provide restricted access to authorized users.



The keyed LC connectivity solution allows manageable and easily identifiable network segregation by using of a range of physically unique keyed connector and adapter combinations. With the help of keyed LC connectivity system, network can effectively be limited to certain groups, access levels or customers in a co-location environment, which can provide an increased level of security and stability by protecting against incorrect pathing of circuit.

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