Passage

Passage is a 3D photonic interconnect platform from Lightmatter, designed to eliminate the bandwidth bottleneck in AI training and data center switching. It targets hyperscalers, AI infrastructure builders, and system architects who need to scale interconnect bandwidth beyond the limits of traditional electrical I/O and discrete optics. By embedding fiber-optic connections directly beneath processors, Passage enables massive bandwidth density across the entire die area rather than being confined to chip edges (shoreline). The platform is available in L-series (near-package, on-board, co-packaged) and M-series (interposer co-packaged) form factors, covering the spectrum from pluggable optics to full 3D integration. Lightmatter also offers the Guide light engine, based on Very Large Scale Photonics (VLSP) technology, which provides an integrated laser source to power Passage interconnects at hyperscale densities.

Passage's Edgeless I/O architecture places optical I/O across the full die area, allowing bandwidth density to scale with area (mm²) rather than perimeter. Specific products include: the Passage L200, supporting 32 to 64 Tbps aggregate bandwidth via co-packaged optics using 112G PAM4 signaling; the Passage L20, delivering 12.8 Tbps at 4x pluggable density; the Passage M1000 EVK, a rack-level 3D photonic interposer providing 114 Tbps across a 4,000 mm² footprint; the Passage EVK100, a bidirectional link delivering up to 3.2 Tbps per fiber at 1.9 pJ/bit; and the Passage EVK50, a 16-wavelength bidirectional link delivering 800 Gbps per fiber at 2.6 pJ/bit. The Guide light engine generates up to 51.2 Tbps per laser module for NPO and CPO applications, with a minimum of 100 mW per fiber across 16 multiplexed wavelengths, and enables bidirectional photonic links with precise 200 GHz wavelength spacing at +/- 20 GHz accuracy.

Passage competes directly with other photonic interconnect and co-packaged optics solutions from companies like Ayar Labs, Intel (with its silicon photonics), and Marvell (with its PAM4 DSPs and optics), though the provided sources list competitors such as Copy AI, Drift, Clari, Podium, and VERSE AI — which appear to be unrelated AI writing or conversational intelligence tools, not photonics companies. This suggests the extracted competitor list may be erroneous or drawn from a different context. In the photonic interconnect space, Passage's key differentiator is its 3D Edgeless I/O architecture and the VLSP-based Guide light engine, which reduces component counts and assembly complexity compared to discrete ELSFP modules. The first-generation Guide validation platform enables 100 Tbps of switch bandwidth in a compact 1RU chassis, a density that would require approximately 18 conventional ELSFP modules occupying 4RU of rack space.

Passage's primary trade-off is that it is early-stage technology — available only for early access partners, not yet in mass production — meaning deployment risk for hyperscalers who need proven, field-tested solutions today. The platform also requires significant infrastructure changes (new packaging, cooling, and fiber management) compared to pluggable optics, increasing initial deployment complexity. While the Guide light engine promises superior yields and reliability through foundry-style production, the actual field reliability data at hyperscale has not been publicly demonstrated. Additionally, the integration of 3D photonic interconnects may limit flexibility for customers who prefer modular, hot-swappable optical modules. Pricing is not disclosed, but the technology targets the high-end AI cluster and data center switch market, likely commanding a premium over conventional optics.

Not publicly disclosed; available for early access partners with custom pricing expected for hyperscale AI clusters and data center switches.