How Does a Fiber Optic Transceiver Work?
A Fiber optic transceiver usually consists of a transmitter on one end and a receiver on the other end in a single module. They are arranged in parallel so that they can operate independently. Both the receiver and the transmitter operate with their own circuitry, so they can handle transmissions in both directions. These fiber optic transceivers can interface with the single mode and the multimode types of fibers to allow data communication.
In fiber optic data links, the transmitter converts the electrical signal into an optical signal from a laser diode or LED. The light from the transmitter is coupled into the fiber with a connector and is transmitted through the fiber optic cable plant. The light from the end of the fiber is coupled to a receiver where a detector converts the light back into an electrical signal which is then conditioned properly for use by the receiving equipment.
Important receiver performance parameters to consider when searching for fiber optic transceivers include sensitivity, responsivity, and receiver rise time. Important transmitter performance specifications to consider include light source, spectral width, and maximum optical output power and transmitter rise time. In terms of the light source, LEDs are used mainly for short-to-moderate transmission distances. Their spectral output is very broad, but far less focused than a laser. Laser diodes are more expensive than LEDs, but are required for long-distance transmissions. Typically, three types of laser are used: Fabry-Perot, DFB, or VCSEL.
Fiber optic transceivers are designed for use with both single mode or multimode cable. Single mode fiber has a very small core diameter of approximately 8 µm. It is the medium that permits the transmission of the signals at extreme high bandwidth, allowing long transmissions to be possible. Multimode fiber may have a typical core diameter of 50 to 100 µm with a refractive index that is graded or stepped, which supports the transmission of signals in multiple modes. Distances of transmission and transmission bandwidth are less than with single mode fiber due to dispersion.
Common connector types for fiber optic transceivers include Biconic, D4, ESCON, FC, FDDI, LC, Loopback, MTP, MT-RJ, MU, SC, SMA, and ST. General performance specifications to consider include wavelength, operating voltage, data rate, and bandwidth. Common types for fiber optic transceivers include SFP transceiver, SFP+ transceiver, XFP transceiver, CFP transceiver and so on. Every different transceiver meets different applications, so before you buy it you should learn about more details about them.
