Introduction of 100G multi-mode optical modules—SR4/SRBD/SWDM4
394 2023-04-20
With the rapid development of 5G, AI, big data, cloud computing and other services, the data center network is required to develop in the direction of high speed, high density, and efficient operation and maintenance. At present, 100G is widely used in China. This article introduces three mainstream solutions for 100G multimode optical modules.

1) 100G QSFP28 SR4
Interface type: multi-mode MPO-12F
working principle:
The center wavelength of 100GBASE-SR4 is 850nm, which can provide four independent transmission and reception channels, and the operating rate of each channel can reach 25G. The transmission distance is 70m when used with OM3 multimode fiber and 100m when used with OM4 multimode fiber.
2) 100G QSFP28 SRBD
Interface type: multimode duplex LC
working principle
The transmission wavelength of the 100GBASE-SRBD optical module is 850nm and 900nm, and the SWDM wavelength division multiplexing technology is used to multiplex the optical signals of different wavelengths in the same optical fiber for transmission. The transmission distance is 70 meters when used with OM3 multimode fiber, and the transmission distance is 100 meters when used with OM4 multimode fiber
3) 100G QSFP28 SWDM4
Interface type: multimode duplex LC
working principle:
The 100GBASE-SWDM4 optical module adopts SWDM (Short Wavelength Division Multiplexing) short wavelength division multiplexing technology, realizes multiplexing and demultiplexing through MUX/DMUX, and transmits optical signals of 4 bands on a single-core multimode fiber. The windows of the four bands are 850nm, 880nm, 910nm, and 940nm, and the transmission distance can be up to 150 meters when used with OM5 multimode fiber 100 metres)


The three 100G multimode optical modules are all in QSFP28 packaging mode, so they are compatible with 100G QSFP28 ports of equipment from various manufacturers. The transmission distance of the optical module is slightly different.
Because both 100G QSFP28 SRBD and 100G QSFP28 SWDM4 adopt dual-core cabling system, it is easy to upgrade smoothly from the existing GE/10G network. Compared with the traditional 100G QSFP28 SR4 optical module, although the price of 100G QSFP28 SWDM4 is relatively expensive, it saves the cost of wiring, so it has the opportunity to become a new choice for data center wiring.