Irixi's 100G PAM4 QSFP28 LR single lambda optical transceiver is a leading technology for 100G-LR applications interconnection, providing 103.125 Gbps single rate and links up to 10KM transmission distance with FEC over single-mode fiber (SMF). The module multiplexes 4 channels of 25.78 Gbps NRZ electrical inputs into single 103.125 Gbps PAM4 electrical signal by a DSP based gearbox then in turn to convert the electrical signal to 103.125Gbps PAM4 single lambda optical signal by a linear laser driver and single channel 1310nm cooled EML. Oppositely, the receiver side where the module converts a 103.125Gbps single lambda optical signal input into 103.125 Gbps PAM4 electrical signal by single channel PIN Photodiode and linear Trans-Impedance Amplifier (TIA). Then the module de-multiplexes the 103.125 Gbps PAM4 electrical signal into 4 channels of 25.78Gbps NRZ electrical signal outputs. The product complies with the QSFP28 MSA, 100G Lambda MSA and portions of IEEE 802.3bm as well as the RoHS-6 Directive 2011/65/EU6, which is a natural choice for the data center, enterprise, and telecom applications, enabling a lower power consumption, cost efficient, high performance optical transmission connectivity.