Coherent's 400G QSFP-DD-DCO coherent transceiver, with its high transmit output power, paves the way for genuine IP-over-DWDM implementations in metro and regional optical transport networks.
Existing and emerging DWDM transport networks that utilize reconfigurable optical add/drop multiplexers (ROADMs) necessitate a high optical launch power (0 dBm) and a high transmit in-band and out-of-band optical signal-to-noise ratio (OSNR) on their add ports.
However, the new OIF 400ZR and OpenZR+ MSA coherent transceivers in QSFP-DD and OSFP form factors generally have a low transmit output power (-10 dBm), making them unsuitable for ROADM networks. As a result, to bridge the gap between the switch or router and the ROADM, networks still need transponder or muxponder equipment that employs coherent line interfaces either based on the larger CFP2 pluggable form factor, or on discrete component implementations on line cards.
By integrating Coherent's high transmit output power 400G QSFP-DD-DCO transceivers directly into their switches or routers, network operators can eliminate the need for intermediate transponder/muxponder equipment. This not only reduces capital expenditures for network operators but also results in significant operational savings. The IP-over-DWDM architecture facilitated by the Coherent QSFP-DD-DCO reduces the space required in central offices or co-location sites, decreases overall electrical power consumption, minimizes cooling needs, and simply lessens the number of network elements that need to be planned, installed, managed, and maintained.