The string of numbers on the optical module label, such as 850, 1310, 1550, refers to the center wavelength of the laser, in nanometers.They fall in the low-loss interval of the fiber attenuation curve, known as the wavelength window.If the window is selected incorrectly, half of the link margin will be wasted. Each of

the three windows has its own

• task 850 nm with multimode fiber for 100-meter interconnection in the machine room with the lowest device cost
• 1310 nm is a single mode zero dispersion window, a common choice for ten to twenty kilometer level
• links Lowest attenuation of 1550 nm, about 0.25 dB/km, long distance and field links preferred 1550 In exchange for distance, there

is also the cost of dispersion The typical chromatic dispersion

of single-mode fiber in the 1550 window is about 17 ps/(nm · km), which is much higher than the level of near zero in the 1310 window.Gigabit and 100 Gigabit links are not sensitive to this. When 10 Gigabit and above run to dozens of kilometers, the pulse is widened to compress the reception sensitivity.A common practice in engineering is to use 1310 for the middle distance, replace 1550 for the ultra-long distance, and compensate for the dispersion or reduce the single fiber rate if necessary, such as SFP2.5g Single Mode Dual Fiber 40km Optical Module Long-haul models of thistype are clearly marked with a work window. Single-fiber bidirectional

leaning against a pair of wavelength division

of labor When the core resources are tight, you can use one wavelength in each direction, which is a single fiber bidirectional solution.The common pairing is the opposite of the A terminal 1310 receiving 1550 and the B terminal, so the modules or transceivers at both endscannot be installed in reverse. Gigabit single-mode single-fiber-optical-electric fiberoptic transceiver It is this kindof product in pairs, in the Security Video SurveillanceFiber Optic Transmission Solution is used a lot in point backhaul, a two-core optical cable

can double the point. The most reliable way to judge the wavelength in the field is to read the module label or DDM to report the information, and then measure it with a wavelength meter.If a batch of modules with unknown routes need to be filed and sorted out, you can contact EB-LINK for detection and coding, and mark the model, wavelength, and adapted equipment together, phone 0755-83179002.