25G LWDM and 25G MWDM Optical Modules

For WDM wavelength division multiplexing technology, CWDM coarse wavelength division multiplexing and DWDM dense wavelength division multiplexing are commonly used, so CWDM optical modules and DWDM optical modules are also familiar and most commonly used. In this article, let's talk about the relatively rare 25G LWDM optical module and 25G MWDM optical module.

25G SFP28 LWDM optical module adopts LWDM(LAN WDM) fine wavelength division multiplexing technology (O band) and has 12 wavelengths, of which eight wavelengths are according to the standard wavelength that divides the O band spectrum according to 800GHz, and the other four wavelengths are multiplexed with the four wavelengths of 25G CWDM optical module, which are 1269.23nm,1332.41nm,1313.73nm and 1291.10nm respectively. The wavelength interval is 4nm, which is much narrower than the wavelength interval of the 25G CWDM optical module, so a larger wavelength shift will occur. Regarding wavelength shift, there is another influencing factor. Under normal circumstances, the operating temperature of the SFP28 LWDM optical module is -40 ℃ to 85 ℃, and the transmission distance is 10KM-40KM.

LWDM optical module, like other 25G WDM optical modules, can also realize multi-channel signal transmission on one optical fiber, and its cost is lower, mainly in its structural design. Compared with SFP28 CWDM optical module, the wavelength of SFP28 LWDM optical module is located in the low dispersion region, and only PIN receiver can be used at the receiving end to meet the transmission requirements. Compared with SFP28 DWDM optical module, SFP28 LWDM optical module does not necessarily use EML laser, but relatively cheap DML laser.

25G SFP28 MWDM optical module adopts MWDM(Metro WDM) medium wavelength division multiplexing technology. On the basis of using the first 6 waves of SFP28 CWDM, the center wavelength is shifted from right to right by 3.5nm. DFB laser (with TEC) is used to realize 12 wavelengths, the luminous power range is 0-6dBm, the terminal sensitivity is-14dBm, the maximum power consumption is less than 2W, and the transmission distance is 10KM, which meets the application of industrial scenarios.

, it is worth mentioning that the SFP28 MWDM optical module combines the optical layer top tuning technology to realize the OAM mechanism, with remote optical path protection, communication fault location, business performance detection and other functions, which can effectively improve the efficiency of network system management and operation. At the same time, there are two receiver configuration options, APD and PIN, which can meet the application requirements when users increase optical path protection switching or larger link segments.