MTRJ connector

The MTRJ connector is a small duplex connector. It can accommodate two optical fibers simultaneously in a small body. Its body and ferrule are made of plastic and are available in male and female versions, secured with metal pins.

The increasing deployment of fiber optics in data centers, telcos, wide area networks, local area networks (LANs) and building backbones raises questions about the size of fiber optic connectors.

Using large connectors such as ST, SC, etc. will increase the usable area, resulting in higher installation costs and making it difficult to expand connections.

So, what's the solution?

The optical fiber connector

This solution creates a small form factor (SFF) connector. SFF connectors help reduce deployment costs and save floor space for cables and equipment in fiber optic installations because they allow multiple fiber connections to be placed in the same space. In the late 90's, different types of SFF connectors were developed, but until today, only two have succeeded: MTRJ and LC.

The MTRJ connector was developed by AMP and is currently advertised as the ultimate SFF connector. Inspired by the MT ribbon connector design, AMP has created an inexpensive MT connector that holds two optical fibers in a plastic ferrule.

The LC connector is a small, low insertion and low loss connector created by Lucent Communications to meet the needs of its customers. It is made of plastic and holds the fiber in a ceramic or zirconia ferrule.

Two LC connectors can fit into a duplex assembly, occupying the same space as a single SC.

But which connector to choose?

LCD connector

LC connectors have better insertion loss and return loss

Why? Provides better connector-adapter-connector mating quality due to its 125um ceramic ferrule. In contrast, MTRJ ferrules are made of plastic and use metal pins to align the fibers.

Cleaning LC connectors is easier because they allow traditional fiber optic cleaning methods to be used. MTRJ connectors are difficult to clean due to the alignment pins.

LC connectors can be spliced and installed in the field using the same methods as SC and ST, while MT-RJ connectors require both fibers to be installed/spliced at the same time, which compromises overall performance.

LC has become the connector of choice for transceivers for high-speed applications, as most manufacturers support the LC interface and offer 10Mbps to 10Gbps applications.

However, MT-RJ multimode connectors have seen little support among fiber optic transceiver and LAN equipment manufacturers, especially for 100BASE-FX interfaces.