The SONT 100G QSFP28 LR1(QF28-3G100-10) optical transceiver integrates the transmit and receive path onto one module. On the transmit side, A DSP based gearbox is used to convert 4x25Gbps NRZ signals to 1x50Gbaud PAM4 signal, DSP output the PAM4 signal to laser drivers, which control one EML with 1310 nm center wavelengths. The optical signals are coupled into a single-mode fiber through an industry-standard LC connector. On the receive side, 1310nm PAM4 optical receiver data streams is coupled to a PIN PD and PAM4 transimpedance amplifier, DSP convert the PAM4 signal to 4x25G NRZ signal and output to the module electrical interface. This module features a hot-pluggable electrical interface, low power consumption, and 2-wire serial interface.