How Much Do You Know About Fiber Optic Transceiver?

Fiber Optic Transceiver(Transmitter and Receiver)

Fiber Optic Transceiver, also called fiber optic transmitter and receiver, is a device which includes a LED or laser source and signal conditioning electronics that is used to inject a signal into fiber. It is composed of three basic functional modules, including optoelectronic devices, the optical signal interface and the functional circuit. Optoelectronic devices includes a transmitter and receiver.

Information is sent from a source to a transmitter by means of an electricity signal. The transmitter then takes an electrical input and transfers it to an light signal. The light signal from the transmitter is coupled into the fiber with a connector and is transmitted through the fiber optic cable plant until it reaches a receiver. The fiber optic receiver captures the light from a fiber optic cable, decodes the data it is sending and then converts the light signal into an electricity signal. A transceiver is a device which combines the functions of both the transmitter and receiver.

Sources for Fiber Optic Transmitter

The sources used for fiber optic transmitters need to meet several criteria: it has to be at the correct wavelength, can be modulated fast enough to convert data, and be able to be coupled into the fiber. LEDs, fabry-petrot (FP) lasers, distributed feedback (DFB) lasers and vertical cavity surface-emitting lasers (VCSELs) are the four commonly used types of sources for a transmitter which can convert electricity signals into light signals. They are tiny semiconductor chips. FP lasers emit light from the side of the chip, while the LEDs and VCSELs are fabricated on semiconductor wafers so that they emit light from the surface of the chip.

Detectors for Fiber Optic Receiver

Fiber optic receivers use semiconductor detectors (photodiodes or photodectors) to convert light signals into electricity signals. Silicon photodiodes are used for short wavelength links (650 for plastic optical fiber and 850 for glass multimode optical fiber ), while InGaAs (indium gallium arsenide) detectors are usually used for long wavelength, because InGaAs detectors have lower noise than germanium that allows for more sensitive receivers.

Types of Fiber Optic Transceiver

There are a number of fiber optic transceivers available in the market. And they differ in the type of connections, data transmission speed, as well packing forms. According to the package, there are several commonly used types of fiber optic transceiver, including SFP, SFP+, XFP, QSFP, GBIC.

SFP Transceiver: SFP is the abbreviation of Small Form Factor Pluggable, which is used for the conversion of light and electricity signals. SFP is a mini version of GBIC, and it has all the functions of GBIC, for example it can transmit over one gigabit signals and it is hot-pluggable. Because SFP modules can be easily interchanged, it is more convenient for people to upgrade and maintain fiber optic networks than has been the case with traditional modules. A single SFP module can be removed and replaced for repair or upgrading, which can save substantial cost both in maintenance and in upgrading efforts. It interfaces a network device motherboard (for a switch, router, media converter or similar device) to a fiber optic networking cable.

SFP+ Transceiver: The SFP+ transceiver whose full name is Enhanced Small Form Factor Pluggable, is a kind of fiber optic transceiver to achieve the conversion of light and electricity signals. SFP+ transceiver is an enhanced version of the SFP that can transmit data rates up to 10 Gbps. It has the same appearance and connector as the SFP, but it can provide a higher speed than SFP. In general, when a SFP can support over 8Gbps, it can be called as SFP+.

XFP Transceiver: The XFP (10 Gigabit Small Form Factor Pluggable)is a hot-swappable and protocol-independent fiber optic transceiver for the conversion of light and electricity signals in high-speed computer network and telecommunication links which use fiber optics. Before the XFP was created, the transmission speed could only reach 1.25Gbps, 2.5Gbps or 4Gbps. But this speed is not able to adapt to the development of network. Thus a XFP transceiver is designed to support 10G data per second which improves the communication speed greatly.

QSFP Transceiver: The QSFP (Quad Small Form Factor Pluggable) is a compact, hot-pluggable transceiver used for data communication applications, and it interface networking hardware to a fiber optic cable or active or passive electric copper connection. With the development of technology in the field of networking, QSFP is designed to achieve higher data rates, which enables the data transmission rate to reach as high as 40Gbps. QSFP enhances work efficiency to a large extent, with its high-density, compact size, and low power consumption.

GBIC Transceiver: GBIC transceiver means Gigabit Interface Converter. It converts light signals to electricity signals, and electricity signals to light signals. It is the first standardized fiber optic transceiver which was typically used in fiber optic and Ethernet systems as an interface for high-speed networking. And its data transfer rate could reach one gigabit per second. With the appearance of GBIC, people could achieve long distance communication in spite of the limitation of bandwidth. However, with the fast development of technology, it cannot meet the demand of people any more. And with more and more better transceiver created, GBIC transceiver is no longer popular and is replaced gradually.

Fiber Optic Transceiver is an important device used for the transition of light and electricity in fiber optic communication. According to different capacity need, there are different connectors of fiber optic transceivers. With the help of this article, it will be easier for users to choose a right transceiver they need.