Irixi's 50G PAM4 QSFP28 LR BIDI optical transceiver is well designed for 50G Ethernet interconnection, providing an aggregated signaling rate of 53.125 Gbps and links up to 10KM transmission distance over single-mode fiber (SMF). The module multiplexes 2 channels of 26.5625Gbps NRZ electrical inputs into single 53.125 Gbps PAM4 electrical signal then in turn to convert the electrical signal to 53.125Gbps PAM4 optical signal by a linear laser driver and 25G 1270/1330nm DFB laser. Oppositely, the receiver side where the module converts a 53.125Gbps optical signal input into 53.125 Gbps PAM4 electrical signal by PIN Photodiode and linear Trans-Impedance Amplifier (TIA). Then the module de-multiplexes the 53.125 Gbps PAM4 electrical signal into 2 channels of 26.5625Gbps NRZ electrical signal outputs. The module features a hot-pluggable electrical interface, a single LC connector, and is designed to meet the QSFP28 Multi-Source Agreement (MSA) form factor, IEEE 802.3cn 50GBASE-LR, 50GAUI-2 C2M, as well as the RoHS-6 Directive 2011/65/EU6, which is an ideal choice for the 5G optical middlehaul links and backhaul links transmission connectivity.