GIGALIGHT 400G QSFP-DD DR4+ silicon optical module is an enhanced version of DR4 and supports a larger transmission distance. The product complies with the IEEE 802.3bs 400GBASE-DR4 specification and supports 400G Ethernet rate (425Gb/s) full-duplex links up to 2km. Thanks to the advantages of high signal quality and low mass production cost brought by silicon photonics technology, as well as the advantages of low device cost brought by single-wavelength 100G PAM4 modulation technology and parallel optical engine technology, this product has now become a data center 2km,which is one of the most cost-effective solutions for domestic 400G interconnection.