People's desire for high-speed optical network promotes the vigorous development of the entire optical communication industry, including the independent research and innovation of optoelectronic device technology and many other technologies. At this stage, most of the data centers have deployed 100G network. In 100G medium range 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 transmission optical modules.

Different laser. 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.

Different optical connectors. 100G QSFP28 CWDM4 is duplex LC connector, 100G QSFP28 PSM4 is MPO connector.

Different fiber types. 100G QSFP28 PSM4 needs to be connected with banded single-mode MPO fiber jumper (8-core), while the 100G QSFP28 CWDM4 uses duplex single-mode LC fiber jumper.

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

Different wavelength. The center wavelength of 100G QSFP28 CWDM4 is 1271, 1291, 1311, 1331nm, while that of 100G QSFP28 PSM4 is 1310nm.

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

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

Different cost. The structure of 100G QSFP28 CWDM4 is more complex than that of 100G QSFP28 PSM4. The manufacturing cost is higher, so the price is relatively higher.

The above is the difference between the 100G QSFP28 CWDM4 optical module and the 100G QSFP28 CWDM4 optical module shared by ETU-LINK. In the future, we will continue to share the product knowledge and solutions of the optical module. Thank you for your support!