Media Connector for Fiber Optic Cable

There are many types of fiber connectors based on fiber type, application, form factor, ferrule size. Here we divide the fiber connector into two major categories based on the number of fiber strand and ferrule size. Strand Fiber is a single strand of Glass (optical fiber) used to send Data.

The fiber connector which uses single fiber strand categories as Mono Strand  Fiber Connector that contain single fiber cable can be a single-mode fiber or multimode fiber end connected with single/Mono fiber connector. Some Mono connectors are available in the duplex version where two fiber strands are used.

The Extended cylindrical tip of a connector that makes contact is known as Ferrule

Mono fiber connector further classified into three categories based on ferrule size. The ferrule size could be 2.5mm.1.5mm, which is more common, and other variance ferrule size connectors are also available.

The fiber connector which uses multiple fiber strand in one connector categories as Multiple Fiber connector. it is further categories as Duplex connector that contain only two fiber strand in the single connector and another one is Ribbon fiber connector which uses more than 4 fiber strand in a single connector.

Fiber optic cable terminated with fiber optic connectors on both ends is known as Fiber optic patch cable.

Fiber optic cable terminated with fiber optic connectors at one end and another end of the wire is simply exposed known as fiber pigtail.

2.5mm Ferrule Connector

ST

• ST- stands for Straight Tip

• 5mm Diameter Ferrule Connector

• It is available in simplex type only i.e only one connector.

• Single-mode and multimode both fiber are used in this connector.

• The coupling mechanism is bayonet type in ST connector

SC

• SC-Standard Connector /Subscriber Connector /Square Connector

• 5mm Diameter Ferrule Connector

• It has a push-pull/Snap coupling mechanism

• It is available in simplex and Duplex type and used in both single and multi-mode fiber

FC

• FC- Ferrule Connector / Fiber Channel

• 5mm Diameter Ferrule Connector

• It has a screw locking mechanism

• It is designed to use in high-vibration environments

• It is available in simplex type only i.e. only one connector

• Single-mode and multimode both fiber are used in this connector

1.25mm Ferrule Connector

LC

• LC-Lucent Connector/Local Connector /Little connector

• 25mm Diameter Ferrule Connector

• It has Snap coupling mechanism

• It is available in simplex and Duplex type and used in both single and multi-mode fiber

MU

• It looks like a miniature SC connector is about half of the SC size a reduced footprint and used in dense applications.

• 25mm Diameter Ferrule Connector

• push-pull Locking Mechanism

• It is available in simplex and Duplex type and used in both single and multi-mode fiber

E2000

• It has a push-pull latching mechanism

• 25mm Diameter Ferrule Connector

• It has a spring-loaded shutter which fully protects the ferrule from dust and scratches

• When it is plugged into the adapter the shutter opens automatically

• It is also called LX.5 Connector

• It looks like LC connector with shutter

• It is used for both Single and Multimode Fiber

Other single fiber connectors

SMA905/SMA906

• SMA-Sub Miniature Version A

• 14mm Diameter Ferrule Connector

• SMA906 has step ferrule connector whereas SMA905 has full cylindrical ferrule

• Available in Simplex only for multimode fiber

• Used in medical and Industrial Application

D4

• 5mm Diameter Ferrule Connector

• Available in Simplex only

• It is Obsolete, not much used in toady’s network

BICONIC

• One of the first connectors employed in fiber optic

• It exhibits a cone-shaped ferrule that helps to align the optical fibers at the connection interface.

• It is Obsolete

• Available in Simplex only

• Used in multimode and Single-mode fiber

• It is Obsolete

• Available in Simplex only

• Used in multimode and Single-mode fiber

DIN

• DIN connector is half the size of the FC connector

• Doubles the port density compared to conventional fiber optic connectors

• Available for Single and multimode Fiber

Duplex Only fiber connector

MT-RJ

• MT-RJ Mechanical Transfer Registered Jack

• Small Form-Factor Connector

• Available in Male/Female Connectors, or a plug and jack format

• The overall size is about the same as a RJ45 connector.

• The only duplex multimode connector that holds two fiber in a plastic ferrule.

ESCON

• ESSCON-Enterprise Systems Connection

• Used in IBM mainframe computers for interfacing peripheral storage devices.

• Similar to FDDI connectors, but contain a retractable shroud instead of a fixed shroud.

• 2.55 mm ceramic ferrules

FDDI

• FDDI-Fiber Distributed Data Interface Connector

• It has two 2.5mm ferrule

• ferrules are sheltered from damage

• Available in Duplex only for multimode fiber

VF-45(3M Volition)

• Designed by 3M

• Available in Duplex only

• No ferrule available, that reduce cost

• VF-45 plug is inserted into the socket(jack) at a 45-degree angle, pressing a pair of fibers into V-grooves inside the socket.

Opti-Jack(Panduit)

• It resembles RJ-45 type connector

• Available in Duplex only with two ST type ferrules

• 5mm Diameter Ferrule Connector

• Snap-Lock Plug and jack version

• It is a version of Fiber Jack connector design from Panduit Corporation

CS Connector

• CS Connector developed by Senko

• 25mm ferrule technology

• Half-size of LC connector

• Push /Pull Locking Mechanism

• Duplex type connector

• Support for next Gen 200/400 G transceiver QSFP-DD and OSFP

SN Connector

• SN Connector developed by Senko

• 25mm ferrule technology

• Half size of LC connector

• Push /Pull Locking Mechanism

• Duplex type connector

• Designed for OSFP/QSFP-DD Break out an application

• 4 Duplex connectors (total 8-fibers) in OSFP/QSFP-DD footprint

Ribbon fiber connector

MTP/MPO

• MPO – Multi-Fiber Push-On

• MTP – Multi-Fiber Termination Push-On

• MPO is the standard

• MTP is a trademark “US Conec” and high-performance version of MPO connector

• MTP and MPO connectors are interchangeable.

It has two version MPO12– 12 fiber strand and MPO24– 2 rows of 12 fiber strand.

• It has two type

• Male-having two pin

• Female-having two hole  to ensure alignment of the fiber end faces during mating

• Available for both single mode and multimode fiber

• UPC(flat) and APC(8° Angle) version

• 40 and 100GbE configuration

• Fanout or Breakout – Breaking out into LC patches or SC patches four times 4x10G or 10x 10G

Ferrule-Polish and shapes

To minimize the losses the ferrule of fiber connectors are Polish and shape for their return loss reduction. To reduce back reflection and return loss caused by back reflection we use many methods, Which include Polishing Connector Ferrule with different shapes. Different polish shapes reduce return loss differently express with negative decibels. The fewer decibels, The less return loss.

Shapes and polishes used by ferrules to reduce back reflection

• Flat Fiber Connector(FLAT)

• Physical Contact(PC)

• Ultra Polished Connector(UPC)

• Angle Polished Connector(APC)

Flat Fiber Connector(FLAT) 

• The Two Fiber meet but the end faces are polished to be flat

• Relatively large end-face of the connectors

• Leaving a small air gap between two connected ferrules

• It has zero dome-shaped geometry.

• More return loss, having more back reflection

Physical Contact(PC)

• Polished with a slightly curved or spherical design to reduce the overall size of the end-face

• Reducing the air gap between end-faces compared with flat fiber connectors

• Resulting in lower Optical Return Loss(ORL)

• The back reflection is about -40 db

Ultra Polished Connector(UPC)

• The curvature makes them look more like a dome-shaped convex end-face

• It has lower back reflection(ORL)

• Back reflection reduced about -55db

• UPC popular in the market and applications

• UPC is a blue-colored Connector

Angle Polished Connector(APC)

• A fiber connector end face is polished at an 8-degree angle

• It maintains a tight connection, and it reduces back reflection to about -70db

• APC connector color is green

APC and UPC connectors can’t be mated together because doing so will cause poor performance or may damage the connectors.