Fiber Optic Connector types and applications

This article is a continuation of the previous article, “Fiber Optic Connector types and applications: Part 1”.

The structure of fiber optic connectors

Fiber optic connectors are made of three key components.

The first component is the ferrule. It aligns the core of the optical fiber with micrometer accuracy, and is usually made of zirconium ceramics, metal, glass, or plastic.

The second component is the connector body. It supports the ferrule and sheaths the fiber or cable. It is commonly made of metal or plastic.

The third component is the coupling mechanism that provides a mechanical connection between the connector body and the optical device. Screws, bayonets, and latches are often used.

There are also simplex and duplex connectors. Simplex connectors have one connector at each end of the fiber optic cable. Duplex connectors have two connectors at each end of a single cable. Various combinations of these elements result in a wide range of connector configurations.

SC connector

The SC connector was developed in the 1980s. They are characterized by high reliability, durability, and low cost, and have found widespread use. Although connectors before them (ST and FC) were rounded, the SC connector employs a square plastic housing. Fibers are connected with a push-pull mechanism using a 2.5 mm diameter ceramic ferrule. SC connectors are widely used in optical network applications such as cable TV (CATV), inside of optical cabinets, media converters, FTTX (EPON, GPON, etc.).

LC connector

LC connectors use a 1.25 mm diameter ceramic ferrule contained in a plastic housing with a latching mechanism. Some LC connectors have a centering or tuning function that allows the core to be adjusted in various directions after assembly in order to reduce connection losses. With dimensions nearly half of SC connectors, LC connecters are ideal for use in data centers and high-density mounting cabinets. It is commonly used in Fiber To The Home (FTTH) connections, local networks, CATV, data center interconnections (DCIs), etc.

MU connector

MU connectors are miniature connectors with push-pull mechanisms. It is ideal for both SM and MM type fibers and used in high-density connection applications. It features a plastic housing with a 1.25 mm diameter zirconium ferrule. It is commonly used in data centers, telecommunications, cabling, LAN, etc.

FC connector

FC connectors have 2.5 mm diameter ceramic ferrules and use metal screw attachment mechanisms. FC connectors are mainly used for SM fibers and are characterized by their stable connection mechanism. They are used in calibration and reference cables for optical devices.

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Adamant Namiki’s web pages of Fiber optic components are:

• Fiber Optic Connectors / Adaptors
• Optical Fiber Assemblies