Different types of sfp modules 

Classification of SFP Optical Modules
Optical modules are classified into various types to meet diverse needs.

Classification by rate:

Different rates of optical modules have been developed to meet the demands of various transmission rates: FE optical module, GE optical module, 10GE optical module, 40GE optical module.

Classification by packaging:

The higher the transmission rate of the optical module, the more complex the structure. Various types of packaging have been developed to meet different structural requirements. The packaging types applicable to Huawei routers are: SFP packaging, eSFP packaging, SFP+ packaging, XFP packaging, QSFP+ packaging.

SFP (Small Form-factor Pluggable) optical module:

Small form-factor pluggable packaging. SFP optical modules support LC fiber connectors and support hot plugging.

eSFP (Enhanced Small Form-factor Pluggable) optical module:

Enhanced SFP, sometimes eSFP is also called SFP. It refers to SFP with voltage, temperature, bias current, transmit optical power, receive optical power monitoring functions.

SFP+ (Small Form-factor Pluggable Plus) optical module:

It refers to the SFP module with an increased rate. Because of the increased rate, it is sensitive to EMI, so there are more skirts on the shell, and the paired cage has also been relatively tightened.

XFP (10-GB Small Form-factor Pluggable) optical module:

"X" is the abbreviation of the Roman numeral 10, all XFP modules are 10G optical modules. XFP optical modules support LC fiber connectors and support hot plugging. Compared with SFP+ optical modules, XFP optical modules are wider and longer.

QSFP+ (Quad Small Form-Factor Pluggable) optical module:

Four-channel small hot-pluggable optical module. QSFP+ optical modules support MPO fiber connectors and are larger than SFP+ optical modules.

Classification by physical layer standard:

To meet the need for data to be transmitted in different forms, various different physical layer standards have been defined, resulting in optical modules that support various standards, as shown in Table 8-1 "Standard Type".

Classification by mode:

Optical fibers are divided into single-mode fibers and multimode fibers. To use different categories of optical fibers, single-mode optical modules and multimode optical modules have been developed.

• Single-mode optical modules are used with single-mode fibers. Single-mode fibers have wide transmission bandwidth and large transmission capacity, suitable for long-distance transmission.
• Multimode optical modules are used with multimode fibers. Multimode fiber has mode dispersion defect, its transmission performance is worse than single-mode fiber, but it is cheaper, suitable for smaller capacity, short-distance transmission.

The types of optical modules and the corresponding relationship between each type are shown in Table 8-1.
Table 8-1 Table of types of optical modules and the corresponding relationship between each type
 

Packaging type	Rate	STANDARD	Describe
SFP	FE	100BASE-FX（IEEE 802.3u）	Reception and transmission each use a multimode fiber, used for transmitting FE signals within 2km.
	GE	1000BASE-BX（IEEE 802.3ah）	Supports single-fiber bidirectional communication, a single single-mode fiber can be used for both reception and transmission, used for transmitting GE signals within 10km.
eSFP	FE	100BASE-LX（IEEE 802.3ah）	Reception and transmission each use a single single-mode fiber, used for transmitting FE signals within 80km.
		100BASE-BX（IEEE 802.3ah）	Supports bidirectional on a single fiber, a single single-mode fiber can receive and transmit, used for transmitting FE signals within 15km.
	GE	1000BASE-SX（IEEE 802.3z）	Supports bidirectional on a single fiber, a single single-mode fiber can receive and transmit, used for transmitting GE signals within 1km.
		1000BASE-LX（IEEE 802.3z） 1000BASE-LX10（IEEE 802.3ah）	Reception and transmission each use a single single-mode fiber, used for transmitting GE signals within 40km.
		1000BASE-EX	Reception and transmission each use a single single-mode fiber, used for transmitting GE signals within 40km.
		1000BASE-ZX	Reception and transmission each use a single single-mode fiber, used for transmitting GE signals within 100km.
		1000BASE-BX10（IEEE 802.3ah）	Supports bidirectional on a single fiber, a single single-mode fiber can be used for receiving and transmitting, used for transmitting GE signals within 40km.
		CWDM	Coarse Wavelength Division Multiplexing (CWDM), a single single-mode fiber can transmit multiple signals, used for transmitting GE signals within 80km.
		DWDM	Dense Wavelength Division Multiplexing (DWDM), a single single-mode fiber can transmit multiple signals, used for transmitting GE signals within 120km.
SFP+	10GE	10GBASE-USR	Receive and transmit use a single multimode fiber separately, used for transmitting 10GE signals within 100m.
		10GBASE-BX	Supports bidirectional single fiber, a single single-mode fiber can receive and transmit, used for transmitting 10GE signals within 10km.
· SFP+ · XFP	10GE	10GBASE-SR（IEEE 802.3ae）	Reception and transmission each use a single multimode fiber, used for transmitting 10GE signals within 400m.
		10GBASE-LR（IEEE 802.3ae）	Reception and transmission each use a single single-mode fiber, used for transmitting 10GE signals within 10km.
		10GBASE-ER（IEEE 802.3ae）	Reception and transmission each use a single single-mode fiber, used for transmitting 10GE signals within 40km.
		10GBASE-ZR	Reception and transmission each use a single single-mode fiber, used for transmitting 10GE signals within 80km.
QSFP+	40GE	40GBASE-SR4（IEEE 802.3ba）	Reception and transmission each use a single multimode fiber, used for transmitting 40GE signals within 400m.
		40GBASE-LR4（IEEE 802.3ba）	Reception and transmission each use a single single-mode fiber, used for transmitting 40GE signals within 10km.

 

Composition of SFP Optical Modules

SFP optical modules mainly consist of the following parts:
Photoelectric converter: converts electrical signals into optical signals for transmission;
Interface chip: responsible for the transmission and reception of signals;
Sub-board: contains all the electrical components;
Shell: protects and secures the internal components.

Applications of SFP Optical Modules

SFP optical modules are widely used and are suitable for data centers, Gigabit Ethernet, ATM, optical fiber communication, etc. They are commonly used in network equipment interfaces, such as switches, routers, network cards, host adapters, etc. In addition, SFP optical modules can also be used to build long-distance fiber optic links and interconnect local area networks and wide area networks.