The Difference Between Single Mode & Multimode Fiber Optic Connectors

Fiber-optic cables are used in data communications such as telephone lines, cable television and broadband Internet. The cables consist of flexible transparent glass fibers that are connected to electronic devices with modulators. The modulators receive data from the sending device and encode it into light pulses made by LED transmitters in the cable connection. The LED sends the encoded light pulses from one end of the fiber to the other. At the other end of the cable, the light pulses are sent into a detector that converts the data back into it original format before sending it to the receiving device.

1. Fiber-Optic Connectors

   • Fiber-optic cables are connected with special connectors or spliced together. Fiber-optic connectors consist of a ferrule, a connector body and a coupling mechanism. The ferrule is a thin cylinder that holds the optic fiber in its hollowed-out center. Fiber-optic connectors can be made out of metal, plastic or ceramic. The connector body is made of plastic or metal. It holds the ferrule and connects to the outer jacket of the cable. The coupling mechanism is the body that holds the connector in place when it is attached to an electronics device. Fiber-optic connectors can be a push-and-click latch clip, a screw-in connector or a turn-and-latch bayonet-style nut connector.

   Single Mode and Multimode

   • The mode of a fiber-optic cable is the path that data or light signals travel through. The core diameter of a multimode-fiber-optic cable is larger than a single-mode-fiber-optic cable. Single-mode cables allow a single wavelength and path for light to travel; multimode fiber is used to patch cable to a desktop or a patch panel to computers or televisions.

   Single Mode Connectors

   • Single-mode connector boots are blue or white. The ferrule of the connector is often made out of zirconia, a type of ceramic. The single-mode ferrule has a smaller hole than the multimode ferrrule, which is not detectable by the naked eye.

   Multimode Connectors

   • Multimode-connector boots are beige or black. The boot is the part of the connector that is covered by a sleeve where the fiber-optic cable ends. The ferrule of a multimode connector can be made out of stainless steel, plastic composite or ceramic zirconia.