The FIBERSTAMP 400G QSFP-DD PSM O-band DWDM4 is a Four-Channel, Pluggable, Parallel, Fiber-Optic QSFP 28 PSM4 for 400G or 200G Ethernet Metro-Access over DWDM applications and it is compliant to QSFP-DD MSA, IEEE 802.3bs protocol and 400GAUI-8 standards. The silicon photonics transceiver is based on a new state-of-the-art silicon photonics (SiPh) platform. It uses SiPh chips that integrate a number of active and passive optoelectronic components, 3D packaging technology and industry-leading 7nm DSP chips. It is a cost-effective and lower power consumption solution for 400GBASE data center. 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 a two-wire serial interface.