Tag Archives: Fiber Optic Connector

Selecting Right Fiber Optic Patch Cables

There are various fiber optic patch cables for different applications. Fiber optic jumper cables are available in OS1, OS2 single-mode types and OM1, OM2, OM3, OM4 multimode types. Fiber optic jumper cables are terminated on both ends with a high performance hybrid or single type fiber optic connector, such as SC, ST, FC, LC, MTRJ, or E2000 connector in simplex or duplex. How to choose right fiber optic patch cables for your networks? Here are 6 factors that you need to take into consideration.

Connector Type

A fiber optic patch cable is terminated on both ends with a fiber optic connector, such as LC connector, SC connector, ST connector, FC connector, or MPO/MTP connector. Different connectors are used to plug into different devices. If ports of devices in the both ends are the same, we can use fiber optic patch cables with the same type of connectors on both ends, such as LC LC cables, SC SC fiber patch cord, ST ST fiber patch cable, or MPO-MPO patch cables. If you want to connect different ports type devices, fiber optic patch cables with different types of connectors on both ends, like LC SC fiber patch cable, LC to ST fiber patch cable, or SC to ST fiber cable, may suit you.


Connector Polish Type

Other than choosing the right connector type, you also need to choose the right connector polish type, whether the same polish type of the same connector type or different polish types of different connector types on both ends, such as SC APC fiber patch cord, SC/APC to LC patch cable. The loss of APC connectors is lower than UPC connectors. Usually, the optical performance of APC connectors is better than UPC connectors. APC connectors are widely used in applications such as FTTx, passive optical network (PON) and wavelength-division multiplexing (WDM) that are more sensitive to return loss. But APC connector is usually more expensive than UPC connector. With those applications that call for high precision optical fiber signaling, APC should be the first consideration, but less sensitive digital systems will perform equally well using UPC.

Single-mode or Multimode?

Fiber optic patch cable has two propagation modes: multi-mode and single-mode. Single-mode fiber patch cord uses 9/125um glass fiber. It is designed for the transmission of a single ray or mode of light as a carrier and is used for long-distance signal transmission. Multimode fiber patch cord usually uses 50/125um or 62.5/125um glass fiber. It can carry multiple light rays or modes, each at a slightly different reflection angle within the optical fiber core. Multimode fiber optic patch cables is used for relatively short distances because the modes tend to disperse over longer lengths. Typical single-mode fiber optic patch cable used yellow fiber cable and multi mode fiber optic patch cable used orange or aqua fiber cable.


Simplex or Duplex?

Do you need simplex or duplex fiber optic patch cords? There is only one single strand of glass or plastic fiber in a simplex fiber optic patch cord. It is often used where only a single transmit and/or receive line is required between devices. A simplex fiber optic patch cord has only one fiber optic connector at each end, often used for Bidirectional (BiDi) fiber optic transceivers. A duplex fiber patch cord consists of two strands of glass or plastic fiber which are typically found in a tight-buffered and jacketed “zipcord” construction format. The duplex fiber is most often used for duplex communication between devices where a simultaneous and separate transmit and receive are required. Duplex fiber patch cords are used for common transceivers. Simplex and duplex fiber patch cords both are available in single mode and multi-mode.


Cable Jacket

Usually, there are three types of cable jacket: Polyvinyl Chloride (PVC), Low Smoke Zero Halogen (LSZH) and Optical Fiber Nonconductive Plenum (OFNP). You can see there features in figure below and choose the right one for your network.


Besides those three cable jacket types above, there is another common cable, armored cable. The double tubing and steel sleeve construction make these patch cables completely light tight, even when they are bent. These cables can withstand high crushing pressures, which makes them suitable for running along floors and other areas where they may be stepped on. The tubing also provides excellent cutting resistance, abrasion resistance, and high tensile strength.


Cable Length

Fiber optic jumper cables are made in different lengths, usually from 0.5m to 50m. You can choose an appropriate cable length according to the distance between the devices you want to connect.


When choosing a right fiber optic patch cord, you need to consider all these six factors carefully. Single-mode or multimode, simplex or duplex, APC or UPC connector polish type, which one is right for your networks? Which kind of fiber optic connector do you need, SC, ST, FC, LC, MTRJ, or E2000 connector? By figuring out what you need exactly and consider all these six factors, you can make appropriate choices for your applications.

How to Install Fiber Optic Connectors?

As we know, fiber optic patch cord is capped at both ends with fiber optic connectors to allow it to be rapidly and conveniently connected to telecommunication equipment. Fiber optic connector is one of those high quality ceramic components used to achieve accurate and precise connections of the fiber ends. It is a simple device which allows fiber links to be readily connected and disconnected.

How to install fiber optic connectors to optical fibers so that they can achieve accurate and precise connections? The method for attaching fiber optic connectors to optical fibers varies based on connector types. Installation ways of fiber optic connectors largely depends on the connector types. Generally, connectors can be categorized into no-epoxy/no-polish connectors and epoxy-and-polish connectors. The following text elaborates on how to install these two kinds of connectors respectively.

No-epoxy/no-polish Connector Installation

How to install no-epoxy/no-polish (NENP) connectors to optical fibers? A no-epoxy/no-polish connector includes an precisely polished endface. When installing an NENP connector, there is no need to use an epoxy or to polish the endface. The field fiber is mechanically spliced to a factory-cleaved fiber stub. The following picture is an illustration of no-epoxy/no-polish connector.


The installation process begins with preparing the field fiber, which is done by stripping the protective coating down to the bare glass. Once the fiber is cleaned, it is then cleaved with a precision cleaver. Next step is to insert the field fiber into the connector until it is seated against the factory-stubbed fiber and locked into place mechanically by a rotating cam or other means. Typically this step is achieved by using a tool that holds the connector and activates the mechanical splice by a button or lever.

Epoxy-and-polish Connector Installation

How to install epoxy-and-polish (EP) connectors to optical fibers? The most common types of EP connectors use heat- or anaerobic-curing techniques. A heat-cure connector uses heat to harden an epoxy, which takes several minutes. An anaerobic EP connector uses a two-part epoxy, a hardener that is inserted into the connector and an activator on the fiber.

To install an EP connector, an epoxy must be inserted into the connector ferrule first to form a bond between the field fiber and the connector’s ferrule, and then the endface needs to be hand-polished. Next, the field fiber is stripped down to the bare glass and cleaned. If the connector is heat-cure, the fiber is inserted into the connector and placed in an oven for the epoxy to cure. If the type of connector is anaerobic, the bare fiber is painted with an activator and inserted into the connector. Once the epoxy has been cured, the fiber stub which is protruding above the ferrule is scribed and removed. The final step is to polish the endface of the connector using a fixture and several different polishing films.

Notes for Fiber Optic Connector Installation

Besides different installation methods for different connector types, several things need to be paid attention to when installing fiber optic connectors, especially when a fiber patch cord has two different types of connectors, such as ST-LC fiber patch cable or FC-SC fiber optic patch cord.

  • The bared fiber must be thoroughly cleaned with isopropyl alcohol.Never clean the fiber with a dry tissue.Before the connection is made, the end of each fiber must have a smooth finish that is free of defects such as hackles, lips, and fractures.
  • The cable should be cut about one inch longer than the required finished length.
  • Be sure to use strippers made specifically for use with fiber rather than metal wire strippers because damage can occur and then weaken the fiber.

Any problems with a connector, such as poor installation and uncleanness, can greatly influence the transmission and reception of the light power. And such problems may render the fiber optic system inoperative. So it is very necessary to know something about installation of fiber optic connectors.