fiber optic Connectors

Todays and future communication technology demands fast, efficient and safe performance in the data communication process.When installing or upgrading a network, choosing the right connectors can ensure optimal performance.There are many types of connectors in circulation. Previously, the most popular connector was the ST type. fiber optic  connector primarily functions as  terminators using epoxy to hold the fiber in place. In order to achieve accurate and precise connections of the fiber ends, very high quality ceramic components are used.

connectors can be mated and unmated at any time. The commonly used  connector series includes:   SC, ST, FC and LC version.The advantages of this approach are that the connection is robust, the connector can be chosen according to the application, and the connector can be connected and disconnected hundreds or even thousands of time without damaging the connectors. The disadvantages of this approach are that the connectorization takes longer than fusion splicing, requires special tools, and the insertion loss can be higher when compared with fusion splicing.

There are two types of fiber optic connectors namely:

  1. physical contact and
  2. expanded beam.

1. Physical Contact Connectors

Physical contact connectors were originally designed for datacom and telecom systems, operating in benign environments such as telephone exchanges and data centres. Physical contact connectors are the most common type of fiber optic connection.It is also common to provide multiple fibers in a single connector. They are rugged, repeatable, easy to clean, cost-effective, and perform well. In addition, for physical contact connectors, the insertion loss is generally low (approximately 0.3dB). There are many types of fiber optic connectors used in various applications.These physical contact connectors perform well against particle contaminates (dust, mud, etc) and are usually less sensitive to liquid contaminates (water or oil). The physical contact pushes liquid out of the way and the liquid does not degrade the connection. Physical contact connectors are cleaned by wiping the ferrule with a clean cloth or wipe, spraying with a cleaner or washing with water. During a typical fiber termination, the ferrule end-faces are polished on a high precision polishing machine to achieve a radiuses profile to allow the mating optical fibers to contact.An example is the MPO (Multiple Fiber Push-On/Pull-Off-) connector which supports 12 fibers in a single ferrule. Another example is the TFOCA-II® connector which provides 4 or 12 fiber optic channels for harsh environment fiber-optic applications .

FIBER TYPE

HOUSING COLOR

CABLE SIZE

AFL NO.

PACKAGE OF 6

PACKAGE OF 100

FASTCONNECT SC

Multimode 62.5/125 μm, OM1

Beige

900 μm

FAST-SC-MM62.5-6

FAST-SC-MM62.5-100

Multimode 50/125 μm, OM2

Black

FAST-SC-MM50-6

FAST-SC-MM50-100

Multimode 50/125 μm, OM3/OM4 compatible

Aqua

FAST-SC-MM50L-6

FAST-SC-MM50L-100

Single-mode, UPC

Blue

FAST-SC-SM-6

FAST-SC-SM-100

Single-mode, APC

Green

FAST-SC-SMAU-6

FAST-SC-SMAU-100

Single-mode, APC

Green

4.8 mm

FAST-SC48-SMAU-6

FAST-SC48-SMAU-100

FASTCONNECT ST

Multimode 62.5/125 μm, OM1

Beige

900 μm

FAST-ST-MM62.5-6

FAST-ST-MM62.5-100

Multimode 50/125 μm, OM2

Black

FAST-ST-MM50-6

FAST-ST-MM50-100

Multimode 50/125 μm, OM3/OM4 compatible

Aqua

FAST-ST-MM50L-6

FAST-ST-MM50L-100

Single-mode, UPC

Blue

FAST-ST-SM-6

FAST-ST-SM-100

FASTCONNECT LC

Multimode 62.5/125 μm, OM1

Beige

900 μm

FAST-LC-MM62.5-6

FAST-LC-MM62.5-100

Multimode 50/125 μm, OM2

Black

FAST-LC-MM50-6

FAST-LC-MM50-100

Multimode 50/125 μm, OM3/OM4 compatible

Aqua

FAST-LC-MM50L-6

FAST-LC-MM50L-100

Single-mode, UPC

Blue

FAST-LC-SM-6

FAST-LC-SM-100

 

2. Expanded Beam

Expanded beam fiber optic connectors utilize a lens to expand and collimate the light emitting from an optical fiber. This collimated light beam is transmitted through an air gap to a mating connector, where the light is collected and focussed by a second lens into a second optical fiber to complete the connection.In this configuration, there is an air gap between the two optical fibers/lens assemblies .

The mechanical interface between the connectors must be precise. Dust and dirt must not interfere with the alignment of the optical elements. Expanded beam connectors are less susceptible to particle contaminates such as dirt and dust but they perform poorly with liquids or film on the lenses. They can also be very difficult to terminate in the field.

The loss generated by an expanded beam connection is more than that of a physical contact connector due to the lenses, mechanical alignment and sometimes protective windows (approximately 0.8 to 2.5dB typical).

This type of connector performs well against particle contamination on the lens because the beam is expanded to a much larger size than the beam that comes directly from a fiber. However, any liquid or film (such as a fingerprint) on a lens creates significant loss in an expanded beam connector. Expanded beam connectors are also very sensitive to alignment of the lenses. Connectors must always be tightly coupled and kept clean on the mating surface in order to work properly. Cleaning an expanded beam connector must be done with care because any liquid (water, alcohol or another cleaner) that is trapped inside the connector may migrate to the surface of the lens, causing an unacceptable increase in insertion loss.

 

SMA — “Sub Miniature A”; Ferrule diameter = 3.14mm. Due to its stainless steel structure and low- precision threaded fiber locking mechanism, this connector is used mainly in applications requiring the coupling of high-power laser beams into large-core multimode fibers. Typical applications include laser beam delivery systems in medical, bio-medical, and industrial applications. The typical insertion loss of an SMA connector is greater than 1 dB.

ST — “Straight Tip”; Ferrule diameter = 2.5mm. The ST connector is used extensively both in the field and in indoor fiber optic LAN applications. Its high-precision, ceramic ferrule allows its use with both multimode and single-mode fibers. The bayonet style, keyed coupling mechanism featuring push and turn locking of the connector, prevents over tightening and damaging of the fiber end. The insertion loss of the ST connector is less than 0.5 dB, with typical values of 0.3 dB being routinely achieved. Drilled-out, metallic ST connectors, with insertion losses of >1 dB, are used with Newport’s large-core (>140 μm) fibers.

FC — “Ferrule Connector”; Ferrule diameter = 2.5mm. The FC has become the connector of choice for single-mode fibers and is mainly used in fiber-optic instruments, SM fiber optic components, and in high- speed fiber optic communication links. This high-precision, ceramic ferrule connector is equipped with an anti-rotation key, reducing fiber endface damage and rotational alignment sensitivity of the fiber. The key is also used for repeatable alignment of fibers in the optimal, minimal-loss position. Multimode versions of this connector are also available. The typical insertion loss of the FC connector is around 0.3 dB. Drilled- out, metallic FC connectors, having insertion losses of >1 dB, are being used with Newport’s large-core (>140 μm) fibers.

SC — “Subscriber Connector”; Ferrule diameter = 2.5mm. The SC connector is becoming increasingly popular in single-mode fiber optic telecom and analog CATV, field deployed links. The high-precision, ceramic ferrule construction is optimal for aligning single-mode optical fibers. The connectors’ outer square profile combined with its push-pull coupling mechanism, allow for greater connector packaging density in instruments and patch panels. The keyed outer body prevents rotational sensitivity and fiber endface damage. Multimode versions of this connector are also available. The typical insertion loss of the SC connector is around 0.3 dB.

LC — “Lucent Connector”; Ferrule diameter = 1.25mm.

NOTE:

  1. Most fiber optic connectors are plugs or so-called male connectors with a protruding ferrule that holds the fibers and aligns fibers for mating.
  2. physical contact fiber optic connectors have proved to be unreliable in harsh environment applications due to their sensitivity to water and oil and other contaminants whereas , Expanded beam fiber optic connectors function better even in harsh conditions.

As a leading connector manufacturer Tarluz develops, produces and markets connec- tors worldwide to the electronic and communication industry.