The GIGALIGHT 100G QSFP28 CWDM LR1 optical transceiver is designed for using in 100-Gigabit Ethernet links up to 10km over Single-Mode Fiber (SMF). It is compliant with the QSFP28 MSA , 100G Lambda 100G LR1 and CAUI-4(no FEC). The module incorporates 1 channel optical signal, on 1271 or 1291(1311/1331)nm center wavelength, operating at 100Gbps data rate. This module can convert 4 channels of 25Gbps (NRZ) electrical input data to 1 channel of 100Gbps (PAM4) optical signal, and also can convert 1 channel of 100Gbps (PAM4) optical signal to 4 channels of 25Gbps (NRZ) electrical output data.