How to Confirm Whether the DWDM System Meets the Requirements

Dense wavelength division multiplexing refers to an optical fiber data transmission technology, which uses the wavelength of the laser to transmit data within the fiber according to bit parallel transmission or string line transmission. DWDM is an important part of the optical fiber network. It allows IP, ATM, and synchronous optical network/synchronous digital sequence (SONET/SDH) protocols to carry e-mail, video, multimedia, data, and voice data through a unified optical fiber. So how to determine whether a specific DWDM system meets the requirements?

1. Whether the system uses existing equipment and facilities
The 2.5 Gbps DWDM system should be able to fully utilize the existing equipment and optical cable facilities.
2. The system uses fluoride or silicon-based fiber amplifiers
In the 1530- to 1565-nm spectrum, the performance of silicon-based optical amplifiers and fluoride optical amplifiers with filters are good. However, fluoride optical amplifiers are relatively costly to implement. The long-term reliability of fluoride fiber has not been tested.
3. Will manual intervention be required when changing channels?
When increasing or decreasing the number of optical channels to achieve optimal system performance, the optical amplifier will automatically adjust. This is very important because if there is only one channel in the high-energy system, the self-phase modulation phenomenon will degrade the system performance. On the other hand, if the power is too low, the amplifier cannot obtain sufficient gain.
4. Whether the system is stable and reliable
DWDM system with good engineering design and construction provides its own reliability, system availability and system redundancy. Although filters are often affected by humid environments, this is no longer a problem.
5. Whether the laser pump has a connector
Optical amplifiers have two key components: erbium-doped optical filters and amplifiers. When the laser pump activates the erbium element with a laser of a specific wavelength, the erbium will act as a gain medium to amplify the introduced laser signal. If the connector is used instead of direct engagement, slight dirt on the surface may damage the connector.
6. Whether the number of wavelengths and transmission rate of the system can be upgraded
Although this answer is affirmative for various DWDM systems, it is also crucial to upgrade plan. If a service provider uses some specific method to assemble their network into a whole and then upgrade, then the following may happen: the network needs more power or additional signal-to-noise ratio increments. For example, every time a supplier doubles the number of channels or bit rate, an additional 3 dB SNR increment is required.
7. Does the system provide maintenance interfaces that comply with standards?
STL 1 interface can be widely used under DWDM system. The interface should be adapted to the service provider’s usual maintenance plan.