In optical communication networks, SFP (Small Form Factor) optical modules serve as core components for device interconnection, and their wavelength parameters directly determine transmission distance, fiber type compatibility, and network architecture efficiency. Whether for short-distance high-speed interconnection in data centers or long-distance transmission in carrier backbone networks, SFP modules of different wavelengths play an irreplaceable role. This article, based on industry standards and practical application cases, compiles a list of mainstream SFP module wavelengths and provides an in-depth analysis of their technical characteristics and application scenarios, offering authoritative reference for enterprise network selection.
I. The Core Significance of SFP Module Wavelength: Why is it Key to Selection?
The wavelength of an SFP module refers to the center transmission frequency of the optical signal, measured in nanometers (nm). Its value directly affects the degree of optical signal attenuation and transmission distance. For example, the 850nm wavelength attenuates rapidly in multimode fiber and is only suitable for short-distance scenarios; while the 1550nm wavelength has an attenuation as low as 0.19dB/km in single-mode fiber, making it the preferred choice for long-distance transmission. Meanwhile, wavelength division multiplexing (CWDM/DWDM) and bidirectional (BiDi) technologies, through wavelength combination, can significantly improve fiber optic resource utilization and reduce network deployment costs.
Furthermore, wavelength selection must match the fiber type: multimode fiber (MMF) is only compatible with 850nm short-distance wavelengths, while single-mode fiber (SMF) supports 1310nm, 1550nm, and multiplexed wavelengths. This characteristic becomes a core basis for network architecture design.
II. SFP Module Mainstream Wavelength List and Technical Parameters (Industry Standard Version)
According to authoritative industry sources such as Tencent Cloud Developer Community and Finite, SFP module wavelengths can be divided into two main categories: basic transmission wavelengths and multiplexing/bidirectional technology wavelengths. Specific parameters and applicable scenarios are shown in the table below:
|
Wavelength Type |
Specific Wavelength (nm) |
Compatible Fiber Type |
Transmission Distance |
Core Technical Parameters |
Typical Rate |
|
Basic Wavelength |
850 |
Multimode Fiber (MMF) |
Power Consumption ≤0.5W, Attenuation ≈3dB/km |
1G/10Gbps |
|
|
1310 |
Single-mode Fiber (SMF) |
DFB Laser, Attenuation ≤0.35dB/km |
1G/25Gbps |
||
|
1550 |
Single-mode Fiber (SMF) |
EDFA Amplification Support, Attenuation ≤0.25dB/km |
10G/40Gbps |
||
|
CWDM Wavelength |
1270-1610 (20nm spacing) |
Single-mode Fiber (SMF) |
40-80 km |
18 channels, no cooling devices |
10G/100Gbps |
|
DWDM Wavelength |
1525-1565 (C Band (0.8nm spacing) |
Single-mode fiber (SMF) |
80-400 km |
80+ channels, precise wavelength locking |
100G/400Gbps |
|
BiDi wavelength |
1270/1330, 1310/1550 nm |
Single-mode fiber (SMF) |
20-80 km |
Single-fiber bidirectional transmission, LC single-fiber interface |
1G/10Gbps |
(I) Basic Transmission Wavelengths: Core Choices for Short, Medium, and Long-Distance Transmission
1. 850nm Wavelength: Preferred for Short-Distance Multimode Fiber Interconnection
850nm is the most widely used short-distance wavelength in SFP modules. It requires OM3/OM4 multimode fiber and its transmission distance is limited to within 550 meters. Its core advantages are low cost and high compatibility, with a single module power consumption of only 0.5W. It is the mainstream solution for interconnecting servers and switches within data center racks and for short-distance connections between buildings in campus networks, occupying more than 70% of the short-distance optical module market share.
2. 1310nm Wavelength: Mainstay for Medium-Distance Single-Mode Fiber Transmission
The 1310nm wavelength is compatible with single-mode fiber, with a transmission distance of 10-40 kilometers. It uses DFB laser technology, and the signal attenuation is controlled within 0.35dB/km. This wavelength balances transmission distance and cost, primarily used in metropolitan area network access layers (such as community broadband aggregation), enterprise wide area network branch connections, and is also the fundamental choice for 5G base station fronthaul networks.
3. 1550nm Wavelength: The Benchmark for Long-Distance Transmission
1550nm wavelength optical signals have the lowest attenuation in single-mode fiber. Combined with EDFA optical amplification technology, transmission distances can be extended to over 120 kilometers. Its core application scenarios include long-distance trunk communication (cross-city backbone networks), submarine cable transmission, and cross-regional interconnection of data centers, making it an essential solution for long-distance scenarios exceeding 10Gbps.
(II) Multiplexing/Bidirectional Technology Wavelengths: Improving Fiber Resource Utilization
1. CWDM (Coarse Wavelength Division Multiplexing) Wavelength: Low-Cost, High-Density Multiplexing
CWDM wavelengths cover 1270nm-1610nm, with a total of 18 channels. Adjacent wavelengths are spaced 20nm apart, requiring no precision cooling devices, and the operating temperature range is 0℃-70℃. 1. Wavelength Division Multiplexing (WDM) Wavelength Multiplexers:A single optical fiber can transmit multiple signals of different wavelengths, significantly reducing fiber optic deployment costs and making it widely used in Data Center Interconnect (DCI) and metropolitan area network (MAN) expansion.
2.DWDM (Dense Wavelength Division Multiplexing) Wavelengths: Ultra-high capacity transmission.
DWDM wavelengths are mainly concentrated in the C-band (1525nm-1565nm), with channel spacing as low as 0.8nm, supporting 80+ channels for simultaneous transmission. This technology can carry Tbps-level bandwidth per fiber and is a core technology for operator backbone networks, 5G backhaul networks, and a high-speed interconnection solution for supercomputing centers and AI clusters.
3.BiDi (Bidirectional) Wavelengths: Single-fiber bidirectional communication.
BiDi modules use a pair of complementary wavelengths (e.g., 1270nm transmit/1330nm receive) to achieve bidirectional transmission on a single optical fiber through WDM devices, saving 50% of fiber resources. It is suitable for industrial control and rail transit scenarios where fiber resources are scarce, and is also an economical choice for building corridor access in campus networks. III. SFP Module Wavelength Selection Guide for Different Industry Scenarios
(I) Data Centers: High Density and Low Cost Priority
• Short-distance Interconnection (within racks/between floors): Select 850nm multimode SFP modules, paired with OM4 fiber to support 10Gbps speeds, meeting the high-speed connection requirements between servers and TOR switches.
• Cross-data center interconnection: Utilize 1310nm single-mode modules or CWDM wavelengths, improving port density and reducing rack space occupation through wavelength division multiplexing technology.
(II) Telecom Operators: Long Distance and Reliability are Core Requirements
• Metropolitan Area Network Access Layer: Primarily use 1310nm single-mode modules, compatible with GPON/EPON protocols, ensuring stable transmission from the user end to the aggregation node.
• Long-distance backbone network transmission: 1550nm modules paired with DWDM technology, utilizing EDFA amplification to achieve repeaterless transmission over 80 kilometers, supporting 5G base station backhaul and international optical cable communication.
(III) Industrial and Special Scenarios: Environmental Adaptation and Resource Optimization
• Industrial Control (-40℃~85℃ Wide Temperature Range): Utilizes BiDi bidirectional wavelength modules with a single-fiber design to reduce cable loss, adapting to harsh environments such as smart factories and mines.
• High-Definition Video Transmission: 2.5G SFP modules paired with a 1310nm wavelength enable real-time 4K/8K video transmission within a 5-20 km range, meeting the monitoring needs of smart cities.
IV. Module Technology Development Trends
1. High-Speed Evolution: With the widespread adoption of 400G/800G data centers, coherent optical technologies with a 1550nm wavelength (such as QSFP/CFP) are gradually being applied, reducing power consumption by more than 30%.
2. Integration Upgrade: Silicon photonics technology drives increased integration in CWDM/DWDM modules. Future SFP modules will support more wavelength channels while maintaining a miniaturized design.
3.Intelligent management: The IEEE 802.3ct standard promotes wavelength auto-negotiation technology, reducing manual configuration costs and improving network operation and maintenance efficiency.
V. Conclusion
The wavelength diversity of SFP modules provides flexible solutions for optical communication networks, from short-distance high-speed interconnects in data centers to long-distance trunk transmissions for carriers. Each wavelength corresponds to specific application scenarios and technical requirements. When selecting SFP modules, enterprises need to comprehensively consider transmission distance, fiber type, rate requirements, and cost budget. With the development of optical communication technology, wavelength multiplexing and intelligent management will become the core development directions for SFP modules in the future.
Post time: Dec-08-2025
