What are the differences between 100G QSFP28 PSM4 and CWDM4 optical modules?

People's desire for high-speed optical networks is driving the vigorous development of the entire optical communication industry, including the independent research and innovation of many technologies such as optoelectronic device technology. At this stage, most data centers have deployed 100G networks.

In 100G medium distance optical network transmission, 100G QSFP28 PSM4 and 100G QSFP28 CWDM4 optical modules are the main representatives. Today, ETU-LINK will introduce the differences between the two 100G medium distance optical modules.

1. The laser devices used by the two are different. The optical transmitter of 100G QSFP28 PSM4 is composed of four integrated silicon photon modulators and a distributed feedback laser, while the optical transmitter of 100G QSFP28 CWDM4 is composed of four CWDM uncooled DFB lasers.

2. The optical fiber connectors of the two are different. The 100G QSFP28 CWDM4 is a duplex LC interface, and the 100G QSFP28 PSM4 is an MPO interface.

3. The types of optical fibers used by the two are different. The 100G QSFP28 PSM4 needs to be connected with a banded single-mode MPO optical fiber jumper (8-core), while the 100G QSFP28 CWDM4 uses a duplex single-mode LC optical fiber jumper.

4. The transmission distance of 100G QSFP28 PSM4 is 500m, 2km and 10km, while the transmission distance of 100G QSFP28 CWDM4 is only 2km.

5. The central wavelengths of the two are different. The central wavelengths of 100G QSFP28 CWDM4 are 1271, 1291, 1311 and 1331 nm, while the central wavelengths of 100G QSFP28 PSM4 are 1310 nm

6. The working principle is different. 100G QSFP28 CWDM4 uses coarse wavelength division multiplexing technology to multiplex four different wavelengths into one single-mode fiber for transmission, while 100G QSFP28 PSM4 uses parallel transmission technology to transmit four identical wavelengths with four independent single-mode fibers

7. 100G QSFP28 CWDM4 requires a 4-wavelength CWDM multiplexer, while 100G QSFP28 PSM4 does not.