In the fiber telecommunication network system,with the continuous increasing of the transmission capacity has determined the optical fiber communication become the major means of transmission in the modern information network. The fiber optic transceivers,as the core of optoelectronic device in the WAN,MAN or LAN application,have also developed various types along with the increasing in complexity. Optical transceivers'sharp increasing in diversity needs the development of related technology to meet their application.

Lets'see what fiber transceivers are first. An optical transceiver is composed of optoelectronic devices,functional circuitry and optical interface. The optoelectronic devices include a transmitter and a receiver which are combined and share common circuitry or a single housing. In the transmitter section,a certain bit rate signal after processing by the internal driver chi promote the LD or LED to emit a corresponding rate of the modulated optical signal,the automatic control circuit with an internal optical power,so that the optical signal output power is kept stable. In the receiver section,the input signal with a certain bit rate is converted into an electric signal by a light detection diode and output a corresponding bit rate after preamplifier,which is generally PECL. An alarm signal will be output if the input optical power is less than a certain value at the same time. Types of fiber transceivers can be classified based on the bit rate and packages like below:

Rate: 100Base(megabytes),1000Base (Gigabit),10GE for Ethernet application ; 1555M、622M、2.5G、10G for SDH application.

Package: 1×9、SFF、SFP、GBIC、XENPAK、XFP 1×9 package also called welding optical module,the general speed not exceed Gigabit and is with SC interface. SFF is a small welding optical modules,general speed is not higher than Gigabit with L-C interface generally.

SFF (Small Form Factor),adapted advanced precise optics and integrated circuit technology,with only half size of ordinary 1×9,SC optical module,doubling the optical ports number in the same space,which as a result,increase the ports density of the line and lower the system cost of each port. Besides,since the SFF module uses MT-RJ similar interface with copper network,and the same size with interface of common computer copper,which is conducive to transit the existing copper-based network equipment to a higher rate of fiber optic network to meet the sharp increase in the demand for network bandwidth.

GBIC refer to Gigabit Interface Converter which is hot-swappable Gigabit Interface optical module with SC connector. A gigabit interface converter (GBIC) is a standard for transceivers,commonly used with Gigabit Ethernet and fiber channel. CBIC module is hot pluggable,this feature allows a suitably designed enclosure to be changed from one type of external interface to another simply by plugging in a GBIC having the alternative external interface.

SFP is the abbreviation of Small Form Pluggable,it can be simply regarded as an upgraded version of the GBIC. SFP module is half the volume of GBIC and can be configured double number of ports on the same panel. Other basic functions is the almost the same with the GBIC. SFP is also called mini-GBIC by some switch vendors.

XENPAK transceiver is for Gigabit Ethernet application with SC interface and it is a 10G fiber optic transceiver and supports all optical ports as defined in IEEE 802.3ae. XFP is also a 10G optical module can be used in Gigabit Ethernet,SONET and other systems,with LC interface.

SFP+ or SFP plus is a common transceiver used in Gigabit Ethernet applications,it is different from SFP which supports 100Bse or 1000Base rates. SFP+ transceivers use the newest dimensions of pluggable transceivers in the 10Gbs Ethernet and 8.5Gbs fiber channel. It is with more compact size than X2 and XFP packages,and the power consumption is less than 1W. Besides,it also provides higher installation density then the modern 10Gbps devices. The transmission rate of the SFP plus has reached up to 4Gbps although while with the same the industrial standard of SFP.