US-based Celero raises $140m led by Alphabet's CapitalG

Celero Communications, a US-based developer of coherent digital signal processor (DSP) technology for AI infrastructure, has raised US$140 million in total funding.

The latest round is a US$100 million series B led by CapitalG, Alphabet’s growth fund, with earlier series A and seed rounds totaling US$40 million from Sutter Hill Ventures, Valor Equity Partners, Atreides Management, Maverick Silicon, and others.

The new capital will help it address growing demand for optical connectivity in AI data centers.

Celero’s platform is designed to provide signal processing for AI accelerator clusters and cloud data centers.

The company’s founders, Nariman Yousefi and Oscar Agazzi, previously held senior roles at Marvell, Inphi, Broadcom, and ClariPhy.

🔗 Source: Celero Communications

🧠 Food for thought

Implications, context, and why it matters.

Celero enters a crowded 800G coherent DSP field with unclear edge

Missing specs make the matchup a guess. Rivals include Acacia, which shipped 400G+ pluggables in volume 1, and Coherent, which ran 140 GBaud 800G in 2023 2. Celero has not shared baud rate, process node, or power. That gap clouds whether the DSP reaches ~120 GBaud and 5 nm class targets used in 800ZR plans 3.
Coherent had 800G ZR and ZR+ alpha samples in Q1 2024 4. Acacia introduced 800ZR and 800G ZR+ with Interoperable Physical Coding Sublayer (PCS) proven in field trials 1. OIF held first 800ZR multivendor plugfest at OFC 2024 5. Celero raised $140M, yet gave no tapeout status or partnerships like working 800G systems at OFC 2025 6.

Module makers and network integrators can assess Celero by tracking 2025 to 2026 tapeouts and hyperscaler trials

Optical module builders could gain a merchant DSP option (a third-party chip vendor rather than a vertically integrated one) if Celero hits 800ZR+ numbers. Colt’s 800G ZR+ trial doubled capacity and cut power per bit by 33.3% 1. Track partner announcements and sampling dates tied to 1600ZR standards 1.
Network gear suppliers and systems integrators that serve hyperscalers should compare against Acacia’s Interoperable PCS, field-proven 1. Lumentum’s hybrid photonic integration reached over 2000 km at 400 Gbps 7. If 2025 to 2026 trials deliver equal or better specs, Celero could be a second source cutting lock-in risk for AI data center interconnects where distributed training lifts bandwidth needs 1.