What is SWDM short wave wavelength division multiplexing optical module?

However, most multimode optical modules such as 40G and 100G use a 4-way parallel transmission mode, so using these parallel optical modules will double the number of cabling in the data center and make maintenance more difficult. In order to solve this problem, SWDM short wave wavelength division multiplexing (SWDM) technology has emerged. It uses the wavelength division multiplexing (WDM) technology of single-mode fiber for reference to expand the wavelength range used in transmission, from 850nm used in traditional multimode fiber to 850nm-950nm. It supports four wavelengths of data transmission on a multimode fiber by using a cost-effective short wave vertical cavity surface emitting laser (VCSEL) light source and an optimized broadband OM5 multimode fiber, The required number of optical fiber cores is reduced to 1/4 of the original, while the effective mode bandwidth of optical fiber is improved and the transmission distance is extended.

When the wavelength is greater than 850 nm, the dispersion bandwidth of multimode fiber increases and the transmission distance increases. The working wavelength of SWDM technology starts from 850 nm, and one wavelength is added every 30 nm, namely 880 nm, 910 nm and 940 nm, so the working wavelength of broadband multimode fiber is in the range of 850 nm to 950 nm. In the short wave wavelength division multiplexing module, four optical signals of different wavelengths are multiplexed onto a single multimode fiber. At the receiving end of the module, the signal is demultiplexed and converted into a parallel electrical signal.

The optical modules using SWDM technology include 40G QSFP+SWDM4 and 100G QSFP28 SWDM4. Their interfaces are dual fiber LC and their operating wavelength ranges from 850nm to 950nm. Compared with the parallel SR4 optical module, the SWDM4 multimode optical module can save 75% of the fiber consumption, which is very significant for cost saving and wiring simplification.

SWDM optical module will create greater value for data center customers, because it can take advantage of the existing 10G optical fiber infrastructure, which can not only help customers save capital expenditure, but also reduce the need to deploy new optical fiber from an operational perspective and achieve equipment upgrading.