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BIDI SFP 10Gb Ethernet fiber modules commonly employs the 1270nm and 1330nm wavelength in a pair, primarily due to the following key reasons:
Technical Selection: Located in the “Best Window” of Fiber Optics
The low dispersion advantage of O-band
1270nm and 1330nm are both located in the O-band (Original Band) of fiber optic communication, which ranges from 1260nm to 1360nm.
In this frequency band, the dispersion of single-mode fibers is close to zero. Dispersion can cause light pulses to widen during transmission, limiting the transmission distance. Choosing the O-band can minimize the dispersion effect to the greatest extent possible, ensuring that the signal remains clear at distances of 10km or even further, which is the foundation for achieving transmission between 10km-40km.
Reasonable wavelength spacing
The interval between these two wavelengths is 60nm. This interval is “just right” for WDM (wavelength division multiplexing) technology:
- Large enough: The internal WDM filter can easily and cleanly separate the transmitted and received light, avoiding signal crosstalk.
- Not too large: Ensure that both wavelengths are within the low loss “window” of the fiber, without causing additional transmission attenuation.
Maturity of the Industrial Chain: Using the “Golden Partner” of the 10G era
Deep industrial foundation
The wavelengths of 1270nm and 1330nm were adopted and widely used by the IEEE 802.3 standard as early as the 10G Ethernet era. This means that the core optoelectronic device technologies such as DFB laser (distributed feedback laser), filter, and optical multiplexer that are matched with it are very mature, with high yield and controllable cost.
Smooth technological extension
The BIBI SFP 10Gb Ethernet fiber module adopts DFB laser technology similar to the SFP 10GBASE LR (Long Range) module. Starting from 1270nm/130nm, the subsequent development of long-distance BiDi transceivers such as 20km, 40km, 60km, and even 80km is mostly based on this or using mature bands such as 1490nm/1550nm (SFP-10G-ZR module) for development.
Application and Deployment: The Optimal Solution for Practicality
Standardized pairing logic
BIDI SFP 10G adopt standardized wavelengths, a simple “A/B end” pairing rule has been formed:
- A-end (usually blue pull tab): Send (Tx) 1270nm, Receive (Rx) 1330nm
- B-end (usually red/yellow pull tab): Send (Tx) 1330nm, Receive (Rx) 1270nm
This clear distinction greatly facilitates engineering deployment and reduces the situation of link failure caused by taking the wrong module.
Taking into account future expansion
1270nm/1330nm and 1550nm in the C-band (conventional band) maintain a certain distance. This allows 10G BiDi signals to coexist with traditional cable television (Cable TV) or DWDM (Dense Wavelength Division Multiplexing) signals for long-distance transmission on the same fiber optic cable, leaving space for future network expansion.
Conclusion
Overall, 1270nm/130nm is the optimal balance between technical performance, industry maturity, and engineering convenience. It is not only a “top student” in O-band transmission, but also a mature legacy left to us by the 10G era industrial chain.
Yingda manufacturer and provide various BIDI SFP 10GB Ethernet fiber modules, such as SFP-10G-BX10, SFP-10G-BX20, SFP-10G-BX40, SFP-10G-BX60, SFP-10G-BX40A, SFP-10G-BX80, etc. Contact us for inquiry.
