Data shows, 10G optical modules would be the hottest optical devices within the next few years. Currently usually used 10G optical transceivers are the following: Xenpak, XFP, X2 and SFP modules. They are available in different wavelengths like 850nm, 1310nm and 1550nm. These multi-rate optical transceivers are ideal for enterprise and metro networks along with storage applications requiring fiber channel over Ethernet.

Xenpak
Xenpak may be the launch from the first generation of 10G Ethernet optical module while using standard IEEE 802.3ae 10G additional unit interface (XAUI) as the data path. XENPAK modules are offered for physical layer interfaces supporting multi-mode and single mode fiber optic cables and InfiniBand copper cables with connectors referred to as CX4. Transmission distances vary from 100 metres (330 ft) to 80 kilometres (50 mi) for fiber and as much as 15 metres (49 ft) on CX4 cable. Newer XENPAKs while using 10GBase-LX4 standard operated using multiple wavelengths on legacy multi-mode fibres at distances of up to 300 metres (980 ft), eliminating the necessity to reinstall cable in a building when upgrading certain 1 Gbit/s circuits to 10 Gbit/s.

XFP
The XFP (10 Gigabit Small Form Factor Pluggable) is a standard for transceivers for high-speed computer network and telecommunication links which use optical fiber, and its interface to other electrical components which is called XFI. XFP modules typically operate at near-infrared wavelengths (colors) of 850 nm, 1310 nm or 1550 nm. Principal applications include 10 Gigabit Ethernet, 10 Gbit/s Fibre Channel, synchronous optical networking (SONET) at OC-192 rates, synchronous optical networking STM-64, 10 Gbit/s Optical Transport Network (OTN) OTU-2, and parallel optics links. They are able to operate on the single wavelength or use dense wavelength-division multiplexing techniques. XFP modules make use of an LC fiber connector type, which makes it easily achieve high port density applications.

X2
10G X2 transceiver could be a standardized form factor for 10 Gb/s fiber optic transponders which is used for data transfer rates from 10.3 Gb/s to 10.5 Gb/s. It truly is protocol-specific: Either 10G Ethernet or 10G Fibre Channel versions are available. X2 transceivers are used in datacom optical links only (not telecom), plus they are small compared to old generation XENPAK transceivers. Its electrical interface for that host board can also be standardized and it is called XAUI (4 x 3.125 Gb/s).

SFP+
The improved small form-factor pluggable (SFP+) is definitely an enhanced version of the SFP that supports data rates as much as 10 Gbit/s, the newest industry format supported by many network component vendors. SFP+ supports 8 Gbit/s Fibre Channel, 10 Gigabit Ethernet and Optical Transport Network standard OTU2. Consideration needs to be provided to if the module is linear or limiting. Linear SFP+ modules are most appropriate for 10GBASE-LRM; otherwise, limiting modules are preferred.

In contrast to other optical modules, XFP optical transceiver is the shape most compact cost is the lowest, and for that reason includes a great advantage. XFP has been following Xenpak or X2 following a new generation of products, inexpensive optical module, somewhat like the miniaturization of Gigabit Ethernet pluggable optical module (SFP). XFP module occupied area is only 20% of the Xenpak of pcb (PCB), the power consumption is just 1.5 to two W, can be used to achieve as much as 16-port line card. SFP+ Transceivers leave more circuitry to be implemented around the host board rather than inside the module. They offer customers a dual-rate interface for 10 Gigabit Ethernet and Packet-over-SONET/SDH (POS) connectivity.

Source from A Wide Range Of 10 Gigabit Optic Transceivers