What Are the Types of Optical Modules? Understand Mainstream Classification Methods in One Article

In modern communication networks, optical modules play a core role in high-speed data transmission between connected devices. With the continuous evolution of network technology, the types of optical modules have become increasingly abundant. To better understand and select optical module products that meet one's own needs, this article will sort out common classification methods of optical modules from four dimensions: transmission rate, packaging method, application scenario, and wavelength.

Classification by Transmission Rate: From 100Mbps to 400G, Rate Determines Performance

One of the most basic classification methods for optical modules is based on their transmission rate. Optical modules with different rates are suitable for network environments of different scales and performance requirements, mainly including:

FE (Fast Ethernet, 100Mbps)
GE (Gigabit Ethernet, 1Gbps)
10GE (10G Ethernet)
25GE, 40GE, 100GE
400GE (400G Ethernet)

Among them, the higher the transmission rate, the more complex the structure and manufacturing process of the optical module, and higher requirements are also put forward in terms of transmission distance, power consumption, and heat dissipation. For example, in high-throughput environments such as data centers, 100G and 400G optical modules have become the mainstream choice.

Classification by Packaging Method: Interface Standards Determine Compatibility

The packaging method not only affects the shape, size, and interface type of the module but also directly determines its compatibility with equipment. Common packaging types are:

SFP / eSFP: Suitable for GE and lower rates, small in size, and widely used in access layer equipment.
SFP28: SFP package that supports 25G rate.
QSFP+: Quad small form-factor pluggable module, supporting 40G transmission.
QSFP28: Suitable for 100G networks, with a compact structure and stable transmission.
QSFP-DD: Dual-density QSFP, supporting 400G transmission, and is the development direction of future high-bandwidth applications.
CFP / CXP: Mainly used in early 100G scenarios, but with the rise of QSFP28, they have gradually been replaced.

Choosing the appropriate packaging form is not only related to the performance of the module itself but also directly affects the adaptability and upgrade space of network equipment.

Classification by Application Scenario: Matching Distance and Capacity Requirements

Different application scenarios have different requirements for the transmission distance and capacity of optical modules. Therefore, optical modules can also be divided according to their usage scenarios:

Single-mode optical modules: Suitable for long-distance transmission, with a central wavelength of 1310nm or 1550nm, and a transmission distance of tens to hundreds of kilometers. They are commonly used in backbone networks, metropolitan area networks, etc.
Multimode optical modules: Suitable for short-distance transmission, with a central wavelength of 850nm, and a typical transmission distance of 100m to 500m. They are widely used in data centers, local area networks, etc.

When deploying a network, users should choose an adapted optical module according to the specific scenario to ensure the optimal balance between cost and performance.

Classification by Wavelength: Wavelength Determines Signal Transmission Mode

The operating wavelength of an optical module is also an important classification basis. Different wavelengths are adapted to different types of optical fibers and transmission environments:

850nm: Mainly used in multimode optical modules, suitable for short-distance high-speed transmission.
1310nm: Mostly used in single-mode optical modules, suitable for medium-distance transmission.
1550nm: Suitable for ultra-long-distance transmission and has lower optical attenuation.

In addition, in DWDM (Dense Wavelength Division Multiplexing) technology, more finely divided wavelengths are used to realize concurrent transmission of multiple signals in the same optical fiber.

Faced with a wide variety of optical module products, understanding their basic classification methods helps us make accurate choices according to actual needs. Whether building an enterprise network, upgrading a data center, or deploying a wide-area communication link, choosing the right optical module is an important prerequisite for creating an efficient, stable, and scalable network system. If you have more in-depth needs for the selection or use of optical modules, you are welcome to consult the Aoyuan Yichuang technical service team.