Briefly Analyze the Differences Between the Four Common 100G Optical Transceivers

The four common 100G optical transceivers are different in main transmission mode, transmission medium and transmission distance, wiring structure, and working principle. Now Grentech will explain them in detail.

1. The transmission methods of the four 100G optical transceivers are different

Both 100G QSFP28 SR4 optical transceivers and 100G QSFP28 PSM4 optical transceivers use 12-channel MTP interfaces, and at the same time realize bidirectional 100G transmission of 8-channel optical fibers.

The 100G QSFP28 LR4 optical transceiver and the 100G QSFP28 CWDM4 optical transceiver carry out 100G transmission through 4 independent wavelength channels, and use wavelength division multiplexing technology to multiplex the four wavelength signals onto a single-mode fiber for transmission.

2. The transmission medium and transmission distance of the four 100G optical transceivers are different

100G QSFP28 SR4 optical transceiver, 100G QSFP28 LR4 optical transceiver, 100G QSFP28 PSM4 optical transceiver and 100G QSFP28 CWDM4 optical transceiver have different transmission distances.

The 100G QSFP28 SR4 optical transceiver is usually used with MTP multimode fiber. The maximum transmission distance is up to 70m when used with OM3 fiber, and the maximum transmission distance is 100m when used with OM4 fiber.

100G QSFP28 LR4 optical transceivers are usually used with LC duplex single-mode fiber, and the maximum transmission distance can reach 10km.

100G QSFP28 PSM4 optical transceivers are usually used with MTP single-mode fiber for transmission distances up to 500m.

100G QSFP28 CWDM4 optical transceivers are usually used with LC duplex single-mode fiber, and the transmission distance can reach 2km.

3. The wiring structures of the four 100G optical transceivers are different

The wiring structure of the 100G QSFP28 SR4 optical transceiver and the 100G QSFP28 PSM4 optical transceiver is the same, and both require a multi-fiber wiring structure based on 12 MMF MTP interfaces.

The difference is that the 100G QSFP28 PSM4 optical transceiver operates in single-mode fiber, while the 100G QSFP28 SR4 optical transceiver operates in multi-mode fiber.

The 100G QSFP28 LR4 optical transceiver and 100G QSFP28 CWDM4 optical transceiver are usually used with LC duplex single-mode fiber patch cords, and the dual-pass dual-fiber SMF wiring structure is used.

4. The working principles of the four 100G optical transceivers are different

The working principle of 100G QSFP28 SR4 optical transceiver and 100G QSFP28 PSM4 optical transceiver is basically the same. When the signal is transmitted at the transmitting end, the electrical signal is converted into an optical signal by the laser array, and then transmitted in parallel on the optical fiber.

On reaching the receiving end, the photodetector array converts the parallel optical signals into parallel electrical signals, except that the former is on a multimode fiber and the latter is on a single-mode fiber.

100G QSFP28 LR4 optical transceiver and 100G QSFP28 CWDM4 optical transceiver have the same working principle, both convert 4 channels of 25Gbps electrical signals into 4 channels of LAN WDM optical signals, and then multiplex them into a single channel to achieve 100G optical transmission.

At the receiving end, the module demultiplexes the 100G optical input into 4 channels of LAN WDM optical signals, and then converts them into 4 channels of electrical signal output channels.