Overview of 10G DWDM SFP+ Transceivers
10G DWDM SFP+ (Dense Wavelength Division Multiplexing) modules represent the pinnacle of fiber optic capacity scaling. In short, this technology uses densely packed wavelengths to transmit an enormous number of independent 10G channels over a single fiber pair. Unlike CWDM, which has wide 20nm spacing, DWDM uses much narrower channel spacing, typically 100GHz (about 0.8nm) or 50GHz (about 0.4nm). Consequently, this allows for 40, 80, or even more 10Gbps channels to coexist on the same fiber.
Furthermore, DWDM systems are engineered for long-haul transmission, regularly supporting distances of 80km and significantly more. However, to achieve these distances, the system requires additional components. Erbium-Doped Fiber Amplifiers (EDFAs) are used to boost the optical signal, and Dispersion Compensation Modules (DCMs) are used to correct signal degradation over long fibers. Because every module is tuned to a precise channel on the standardized ITU Grid (primarily in the C-Band), DWDM creates a robust, high-capacity, and interoperable solution for service providers, data center interconnects (DCI), and core network backbones.
Key Features and System Requirements
Our 10G DWDM SFP+ modules are built for the most demanding network environments. Indeed, their capabilities are essential for modern high-speed networks.
- Massive Channel Capacity: First and foremost, DWDM enables 40, 80, or more 10G channels on a single fiber pair, offering unparalleled bandwidth density.
- Long-Haul Transmission: DWDM is the standard for links of 80km and beyond. With proper amplification, it can span hundreds of kilometers.
- ITU Grid Compliance: All modules are precisely tuned to a specific channel on the international ITU-T G.694.1 grid, ensuring interoperability between different vendors’ equipment.
- Fixed and Tunable Options: We offer both fixed-wavelength modules for specific channels and tunable DWDM SFP+ modules that can be electronically configured to operate on multiple channels.
- Amplification and Dispersion Compensation: In addition to the modules and a Mux/Demux, long-haul DWDM links require EDFAs to amplify the signal and DCMs to maintain signal integrity.
Specifications
| Parameter | Value |
|---|---|
| Form Factor | SFP+ (Enhanced Small Form-factor Pluggable) |
| Technology | DWDM (Dense Wavelength Division Multiplexing) |
| Max Data Rate | 10.3125 Gbps per channel |
| Wavelengths | C-Band, ITU Grid Channels (e.g., C17-C61) |
| Channel Spacing | 100GHz (0.8nm) or 50GHz (0.4nm) |
| Max Distance | 80km (un-amplified), 120km+ (with amplification) |
| Required Components | DWDM Mux/Demux, EDFA, DCM |
| Connector | Duplex LC |
FAQ (Technical & product category Questions)
1. When should I choose DWDM instead of CWDM?
Choose DWDM when you need more than 18 channels or when you need to transmit data over distances longer than 80km. DWDM’s ability to be amplified makes it the only choice for true long-haul applications.
2. What is an EDFA and why do I need one?
An EDFA (Erbium-Doped Fiber Amplifier) is a device that boosts the optical signal without converting it to an electrical signal. For DWDM links over approximately 80km, the signal becomes too weak (attenuated) to be read correctly. An EDFA is placed in the fiber line to amplify all the DWDM channels at once, allowing the signal to travel much further.
3. What is a DCM (Dispersion Compensation Module)?
Over long distances of fiber, different wavelengths of light can travel at slightly different speeds, causing the signal pulse to spread out and become distorted. This is called chromatic dispersion. A DCM is a passive component that is installed to counteract this effect, effectively re-focusing the signal pulse to ensure data integrity on links typically over 40km.
4. What does a DWDM channel number like “C21” mean?
The ITU has standardized the channels for DWDM to ensure interoperability. “C21” refers to channel 21 in the C-Band, which corresponds to a specific frequency (192.10 THz) and wavelength (1560.61 nm). Using these standard channel numbers ensures that a Channel 21 module from any vendor will work with a Channel 21 port on a Mux/Demux.
5. What is a Tunable DWDM SFP+?
A Tunable SFP+ is an advanced module that is not limited to a single, fixed wavelength. It can be electronically configured via software to operate on any of the DWDM channels within its range (e.g., C-Band channels 17-61). This greatly simplifies inventory management and provides operational flexibility, as a single module can be used as a spare for any channel in the network.