LAQD-DR4 is a transceiver module designed for 500 m optical communication applications, and it is compliant with QSFP-DD MSA, IEEE 802.3-2018 400GBASE-DR4 and 400GAUI-8 standards. The 425 Gigabit signal is carried over four parallel lanes by one wavelength per lane. This module can convert 8- channel 53.125 Gbps electrical data to 4 parallel channels of optical signals, each supporting 106.25 Gbps data transmission. Reversely, it can convert 4-channel 106.25 Gbps optical signals to 8-channel electrical output data on the receiver side. It has been designed to meet the harshest external operating conditions including temperature, humidity and EMI interference. The module offers very high functionality and feature integration, accessible via the I2C interface.