Research|Optics: OCP 2026 Points to NPO Adoption and New Demand from Copper Replacement

We attended the 2026 OCP Global Summit in San Jose from October 12 to 15, including keynotes from NVIDIA, Broadcom and AMD, and more than twenty optical-interconnect sessions. We also met with Marvell, Credo, Ciena, Cisco, Amphenol, Lightmatter, MACOM and others.

Our week in San Jose yielded four key themes, discussed below. This note concludes with detailed notes for each of the companies we engaged with.

Contents

1. Key Themes

2. NVIDIA: a CPO version of NVL576 but keeps NPO on the table

3. NPO: How everyone else responded

4. NPO: What users want

5. Pluggables strike back: XPO and USFP and their impact on NPO and CPO adoption

6. Light sources, fiber and test: the constraints in focus at OCP

7. Standards and the ecosystem: MSAs landing in quick succession; an argument against NPO multi-sourcing?

8. Copper’s evolving role

9. Company notes

1. Key Themes

Theme 1: Scale-up is still a copper/optics mix; the debate is between NPO and CPO and how outstanding issues with both are resolved

Nobody at OCP said copper is finished. Meta will not replace the copper backplane in scale-up for now, while Broadcom sees in-rack copper staying viable for two more years.

The role of optics grows with scale: Astera Labs says pods beyond 144 GPUs need optics, with copper in the rack and optics between racks from 72 to 576 accelerators, and optical only above 576 accelerators.

Image 1: Astera Labs’ hybrid copper/optical pod: hybrid from 72 to 576 accelerators, all-optical above 576. Source: FUNDA; Astera Labs slide.

Where optics is needed, the debate is about where the optical engine sits: NVIDIA showed it soldered onto the switch package (CPO) while keeping NPO on the table. Meta, Microsoft, Oracle, Alibaba and Huawei lean toward board-mounted, socketed NPO. Alibaba also proposed IPO (Interposer-based optics), a solution in between NPO and CPO.

A key issue is serviceability. The NPO camp sells “replaceable” while NVIDIA counters that NPO is assembled in clean rooms with woven pigtail fibers, so failures mean a factory return and not replacement in the field.

Microsoft and Oracle conceded that without a pluggable module, a single failure has a wider impact. Whoever brings FIT rates down (failures in time, per billion device-hours) and improves testing gets closer to volume orders.

Theme 2: XPO and USFP and their impact on NPO and CPO adoption

Neither form factor changes the NPO or CPO picture until 400G per lane silicon is tested and proven. XPO is closer to market. It already runs at 200G per lane, and Google and Microsoft are the hyperscalers most interested in the form factor. USFP at 400G per lane will require DSPs, TIAs and drivers that suppliers do not have yet. Once these components are available, both keep pluggable optics in scale-out for another generation and could slow NPO and CPO there. Scale-up stays NPO versus CPO (see the high-density pluggables section).

Theme 3: Micro-VCSEL and its impact on NPO and CPO

Micro-VCSELs do not compete with NPO or CPO as they are mainly seen as a replacement for copper, and the first products shown at OCP already replace copper rather than optics. Credo’s ZeroFlap ALC replaces AECs, not pluggables or NPO sockets. Later, as scale-in comes in, micro-VCSELs have the potential to replace the links inside the tray that still use copper, since many slow lanes work better there than a few fast ones. ELSFP with micro-ring is another solution for those links, so Lumentum’s external high-power laser business (see the light sources section) should not be seen as affected either way.

We see micro-VCSEL as incremental for Lumentum, which moved early in favor of the technology. We believe it is the unnamed second emitter on Credo’s SRMO slide. The field is more crowded than InP and its lead is smaller, so whatever share it wins is upside on top of the core business. The takeaway is a copper-replacement story that grows the optical market and leaves existing optics untouched.

Theme 4: Beyond silicon, fiber, lasers and test are now constraints too

We kept hearing the same worry: single-mode fiber will be short, whichever approach wins. Lightmatter expects the shortage in late 2027 to 2028 and says the CPO ramp is gated by test equipment in Taiwan; Astera Labs also pointed to component supply as the constraint. Silicon has not dropped off the list. DSPs, TIAs and drivers for 400G per lane are not yet available from suppliers (see the high-density pluggables section). Lumentum’s CPO capacity is booked into early 2029, as its CEO has said.

2. NVIDIA: a CPO version of NVL576 but keeps NPO on the table

Keynote: a CPO version of NVL576

Most of NVIDIA’s day-one keynote went to MGX 1.2, 800VDC and the Vera CPU; optics got the last few minutes but carried the most news: Vera Rubin Ultra NVL576 links 576 GPUs over NVLink through a next-gen NVLink 7 CPO switch tray, targets 10T+ parameter models and arrives “next year.” This was probably the first time NVIDIA announced optical scale-up at such a large venue; at GTC it only came up in a small workshop.

Image 2: Vera Rubin Ultra NVL576, with 576 GPUs linked through NVLink 7 CPO switch trays. Source: FUNDA; NVIDIA slide.

One thing the keynote made clear is that NVIDIA’s next scale-up domain will be optical. NVL576 spans eight racks and 576 GPUs, far beyond the reach of in-rack copper, and NVIDIA is positioning it for 10T+ parameter models, so cross-rack NVLink has to run over fiber. Where the optical engine sits is still open. The keynote showed a CPO version, with optics soldered onto the NVLink 7 switch tray and the slide labeled “Vera Rubin Ultra NVL576 CPO.” In the NPO session, however, NVIDIA’s own slides said it may build NPO with ODMs and will support NPO through NVLink Fusion, and Kuchta mentioned a soldered-NPO proof of concept. Our earlier channel checks pointed to NPO for NVL576’s cross-rack links. We do not read the keynote as a final decision, only as a sign that CPO remains firmly in contention. We expect the choice to depend on yield and test capacity for co-packaged engines, how failures are handled in the field, and laser supply. Either way, demand for cross-rack optics, fiber and lasers is coming; what remains unsettled is how that value splits between the switch tray and the compute side, and between CPO and NPO engine suppliers.

Supply-side conversations leaned toward NPO. The scale-up systems people described for 2027 are NPO. They put CPO’s volume in scale-out instead, in NVIDIA’s Spectrum-X CPO switches, where our checks indicate it is still a small share of scale-out switching. They saw CPO inside scale-up as 2029 at the earliest. That is later than the “next year” on NVIDIA’s slide and later than Coherent’s 27H2 target for scale-up CPO production (see the Coherent company note). We take the gap as one more reason to treat engine placement as undecided.

On scale-out, NVIDIA presented CPO-based Spectrum-X Photonics multiplane Ethernet, scaling to 512K GPUs on two tiers, with 2.6 ms hardware fault detection, 40% fewer switches, 5x power efficiency and 10x MTBI; Meta, Microsoft and Oracle are listed adopters.

NPO session: “Socketed does not mean field replaceable”

The NPO session on the 13th had ten speakers, and NVIDIA’s Daniel Kuchta, Principal Hardware System Architect, went last, opening with the line that a few things about NPO “need to be cleaned up.” It was the most direct critique of NPO we heard all week, in three points:

• First , based on NVIDIA’s experience, soldered beats sockets. Soldered and socketed describe how the optical engines are attached and either approach can be used with CPO or NPO. NPO’s claimed replaceability advantage comes with its socketed design. Sockets help in prototyping and manufacturing defect screening, but add cost and area, hurt signal integrity and complicate thermals; soldering is cheapest with the best signal integrity.

• Daniel Kuchta said the Spectrum-X CPO switch is in production with all 32 optical engines soldered to the package. NVIDIA’s earlier Quantum InfiniBand CPO switch was socketed, hence “been there, done that.”

Image 3: NVIDIA’s socketed-vs-soldered CPO comparison: “CPO socketed does NOT mean field replaceable... same for NPO”. Source: FUNDA; NVIDIA slide.

• Second , serviceability is “dubious at best.” Even socketed NPO will likely be clean-room assembled with woven pigtails, so it gets shipped back rather than fixed in the field, “a very expensive repair job.” • Third , multi-sourcing is doubtful too. NPO for density or power he understands; for multiple suppliers, “you’re kidding yourself,” since every prototype differs and there are four MSAs, all brand new.

NVIDIA did not shut the door, though: the slide below says it may work with ODMs on NPO and will support NPO through NVLink Fusion, and that CPO, pluggables and NPO will likely coexist in scale-out; Kuchta also has a soldered-NPO proof of concept.

Image 4: NVIDIA on NPO: it may work with ODMs on NPO and will support NPO via NVLink Fusion, but questions the multi-supplier and serviceability claims. Source: FUNDA; NVIDIA slide.

Pluggables stay too. According to Daniel Kuchta, Octal Small Form Factor Pluggable (OSFP) will still be the workhorse. NVIDIA’s announcement of its collaboration with Cisco on Ultra-Dense Small Form Factor Pluggables (USFP) is discussed in more detail in the high-density pluggables section below, together with eXtra-dense Pluggable Optics (XPO) and their collective impact on CPO and NPO adoption.

3. NPO: How everyone else responded