Co-packaged optics (CPO) are inching closer to reality. Broadcom recently announced its first co-packaged switch, which combines its 25.6 Tb/s Tomahawk 4 switch silicon with integrated optical interconnects, during the J.P. Morgan Tech/Auto Forum Conference.

The switch, dubbed Humboldt, is expected to launch in 2022 and will be Broadcom’s first to use CPO. Humboldt will be followed by the launch of a 51.2 Tb/s-capable switch a year later, Alexis Björlin, SVP and GM of Broadcom's optical systems division, said during the conference. Broadcom claims these switches will consume 30% less power and cost 40% less per bit than conventional switches.

The switches were announced alongside 800 Gb/s pluggable transceivers that co-package silicon photonics with a digital signal processor.

Co-package optics move the optical interface from the pluggable module into the switch chassis. While this means the optical interface can’t be as easily swapped, it dramatically reduces the physical distance between the switch silicon and the photonics circuits. This cuts down on the power required to drive the transceivers.

In a recent report, analysts at LightCounting said that while it was unusual for Broadcom to announce these products so far head of shipments, it wasn’t entirely unexpected. “The announcement was not a surprise for Broadcom’s largest customers, but it is a surprise for the broader market that needs to get on-board,” the analysts wrote.

LightCounting called the announcement a starting whistle for the development of CPO, and wrote "the race is on and Broadcom plans to stay in the lead."

Broadcom isn’t the only vendor making moves in the CPO arena. Earlier this month, Cisco teamed up with Inphi to develop co-packaged optical technology.

However, unlike Broadcom, which is targeting 25.6 Tb/s co-packaged optical switches with Humboldt at the outset, Cisco and Inphi are expected to hit the market with 51.2 Tb/s switching in 2024.

While 800 Gb/s pluggables for 51.2 Tb/s switches are possible without CPO, the reduced power requirements enabled by the technology are attractive to certain customers, according to Hugh Durdan, VP of network interconnect marketing at Inphi.

“Power is a major challenge in today’s data centers, and anything that can be done to reduce the power consumption of the equipment in the data center is a benefit to the operator,” he said. “Data center operators are paid for computing and storage, not moving data. Every watt spent on networking, is a watt that can’t be used to generate revenue.”

LightCounting believes Broadcom’s decision to stick with 25.6 Tb/s of capacity for its first CPO switch may be an effort to ease the transition to the new technology, which will take some adjusting.

“The industry consensus is that co-packaged optics will be necessary on 102 Tb/s switches and possibly on 51 Tb/s,” the authors write. “Broadcom starts earlier to give customers more time to kick the tires and test drive the new technology.”