When it comes to SFP optical modules, we are no strangers to it. SFP, which stands for SMALL FORM PLUGGABLE, is one of the most commonly used packages for Gigabit Ethernet optical modules, and is an industry standard for Gigabit Ethernet. So what are the common SFP optical modules?

According to the different types of transmitters and receivers, SFP optical modules can be divided into several categories, and their operating wavelengths, transmission distances, and suitable applications are all different, and this section will introduce the various SFP optical modules respectively.

1000BASE-T SFP Optical Module

This kind of SFP optical module adopts RJ45 interface, usually used with Category 5 cable in copper network cabling applications, the longest transmission distance is 100m.

1000Base-SX SFP Optical Module

1000Base-SX SFP optical module adopts duplex LC interface and complies with IEEE 802.3z 1000BASE-SX standard. It is usually used in multimode applications, and the transmission distance is 550m when used with traditional 50um multimode fiber, 220m when used with 62.5um multimode fiber, and 1km when used with laser-optimized 50um multimode fiber. The transmission distance can be up to 1km with laser optimized 50um multimode fiber.

1000BASE-LX/LH SFP Optical Modules

1000BASE-LX/LH SFP optical modules comply with the IEEE 802.3z 1000BASE-LX standard and can be used in both single-mode and multimode applications. 1000BASE-LX/LH SFP optical modules can be used with single-mode fibers for a transmission distance of up to 10km, and with multimode fibers for a distance of up to 550 m. Note that 1000BASE-LX/LH SFP optical modules work with traditional multimode fibers. It should be noted that when the 1000BASE-LX/LH SFP optical module is used with traditional multimode fiber, a mode conversion jumper should be used at the transmitter side.

1000BASE-EX SFP Optical Module

1000BASE-EX SFP optical modules are typically used in long-haul single-mode transmission applications and can reach distances of up to 40km when used with standard single-mode fiber.

1000BASE-ZX SFP Optical Module

1000BASE-ZX SFP modules are also used in long-haul single-mode transmission applications over distances of up to 70 km. If 1000BASE-ZX SFP modules are to be used in applications where the transmission distance is much less than 70 km, an optical attenuator must be inserted in the link to prevent damage to the receiving end of the module caused by excessive optical power.

1000BASE BIDI SFP Optical Module

1000BASE BIDI SFP optical modules use simplex LC optical ports and are generally used in single-mode transmission applications. This type of optical module needs to be used in pairs, for example, a 1490nm/1310nm BIDI SFP optical module must be used in pairs with a 1310nm/1490nm BIDI SFP optical module. The following diagram shows the operation of a 1000BASE BIDI SFP optical module:

DWDM SFP Optical Module

DWDM SFP optical module is an essential component in DWDM network, it uses DWDM wavelengths with 40 common wavelength channels available, it is a high performance serial optical data transmission module.

CWDM SFP Optical Module

CWDM SFP optical module is an optical module using CWDM technology, which operates at CWDM wavelengths and has 18 wavelength channels to choose from. Like regular SFP optical modules, CWDM SFP optical modules are hot-swappable input/output (I/O) devices used in the SFP interface of a switch or router.

The price and usage of different SFP optical modules vary, and the same SFP optical module produced by different manufacturers can have huge differences in performance and price. Consumers should consider price, usage, compatibility, brand and other aspects when purchasing SFP optical modules.

Additional Learning Hub Resources

SFP Optical Module Wiki 

CSFP Optical Module Wiki 

QSFP-DD Optical Module Wiki 

QSFP28 Optical Module Wiki 

QSFP Optical Module Wiki 

Tunable SFP+ Transceiver Wiki 

10G BIDI SFP+ Optical Modules Wiki 

DWDM SFP+ 10G Optical Module Wiki 

CWDM SFP+ 10G Optical Module Wiki