🚀 #MicroLED# optical interconnects are gaining traction in AI infrastructure! U.S. smart glasses maker Vuzix showcased its Causeway waveguide platform at OCP, supporting Micro LED and VCSEL light sources for high-density optical connections.💡More: 🔗

$AXTI $LITE $COHR If MicroLED stalls, the gain goes to lasers, as Serenity says. But the two lasers he names grow on different wafers, and only one of them is short. VCSELs are gallium arsenide parts for short multimode links, the slot MicroLED was aiming at. The CW lasers that light co-packaged optics, and the EMLs in today's pluggables, are indium phosphide. InP has "only three primary suppliers," per AXT's 10-K: AXT in China, and Sumitomo Electric and JX Advanced Metals in Japan. The laser makers already say where the pinch is. Coherent: "indium phosphide capacity continues to be our primary constraint." Lumentum said in August that ultra-high-power laser demand "has surprised us" and that it has spent three months trying to "secure even more substrate supply." More supply is coming, mostly after 2027. Sumitomo plans about 3x its InP substrate capacity from 2024 to 2028. JX is spending up to ¥120bn over four years to reach 7 to 10 times its fiscal 2025 level. In China, Yunnan Germanium is going from 150,000 to 450,000 wafers a year and Vital Materials to 3 million by August 2029, and those wafers leave China under dual-use export licences. The average 4-inch InP substrate in China was RMB 6,250 in early August, up about 45% since January. So a MicroLED setback lands mostly on the wafer that's already short. AXT reports on Oct. 29, and its licensed exports to Europe are the line we'll read first.

Talk of MicroLEDs is getting ever louder with Credo promising demos at the upcoming OCP Global Summit next month. I also spent about 3 hours at Avicena's office looking at their tech in depth and asking questions. If I can get my observations written up this week on my field trip, you will see the article on Substack next week. Meanwhile, this is a great time to brush up on how exactly MicroLEDs are different from lasers, and why everybody things that reach is a problem. Free to read.

👀 #Samsung# is quietly rebalancing its #MicroLED# strategy — maintaining near-term investment while focusing more on profitability, with wearables and AR/VR reportedly emerging as its next big bet. 💡More: 🔗

Took a field trip to Avicena to try and decipher what all the microLED noise is about. Saw demo of all the tech, tried to understand roadmaps, questioned their limitations and pushed back. Report will go on the newsletter at some point .. Maybe even a @semidoped pod when we line it up

Korean media report that U.S. startup Palomino recently received its first purchase order from a strategic customer, a global hyperscaler, for GaN microLED-based optical interconnect chips for AI infrastructure. First commercial use of microLED chips for optical interconnects?

Research|Optics: ECOC 2026 Takeaways, NPO Gains Momentum as Slow and Wide Takes Shape We attended ECOC 2026 in Málaga last week. The debate between slow and wide and fast and narrow was a recurring topic in presentations and plenary sessions. Companies presented microLED and micro-VCSEL designs and discussed their performance, manufacturing challenges and production timelines. NPO was also in focus, with live NPO demos on the show floor and more discussion of how and when it ramps. This note covers our takeaways from the presentations, demos and conversations with companies, including developments in NPO, scale-in, external lasers, retimers, DSPs, coherent-lite and test and measurement. Detailed Report

💰 #OVCEnterprises# have secured new #funding#, with Starksemi Semiconductor raising over ¥1b ($140m) and MemInTech closing a seed round worth tens of millions of yuan. These firms cover MicroLED chips, compute-in-memory chips, semiconductor materials, and glass storage.

I interviewed the CEO of an $800M stock building displays for AR soldier headsets. With the Army planning up to $22B on AR headsets, $KOPN is the only U.S. company making the MicroLEDs needed to make them useful. Please enjoy my conversation with Michael Murray, CEO of Kopin.

Since people are having fun speculating on $SKHY CPO roadmap supply chains. I'm gonna do my own guess and say SK Hynix is evaluating Celestial/Ayar. Then doing heavy evaluation into microLEDs past first-gen deployments. Both have been kinda working on it for awhile. - Ayar shown up in SK hynix's own website in the context of optical <-> memory links. - Marvell is actively working with SK Hynix in custom memory solutions (and guess who owns Celestial now). Celestial/Ayar are both also cited in SK Hynix's linked Nature Paper, which helps a bit with technical relevance: (121): Stojanovic, V. A UCIe optical I/O retimer chiplet for AI scale-up. In 2025 IEEE Hot Chips 37 Symposium (HCS) 1–22 (IEEE, 2025) - This is Ayar reference (Ayar’s teraphy optical I/O chiplet), Stojanovic is Ayar Lab's co-founder btw. (123): Winterbottom, P. Photonic interconnect for accelerated computing celestial AI photonic fabric module (cough cough Celestial) There's more breadcrumbs out there, but wanted to keep this relatively short-form. For more upstream beneficaries: -> I still think $SIVE is the cleanest read through since they're likely supplying to both Celestial/Ayar. The interposer/packaging IP layer... People were speculating $POET, but Marvell probably vertically integrated players them out this year after the announcement. Given they've had their own SiPH interposer tech/integration IP before Celestials acquisition (eg. presented a silicon-photonics interposer back in 2023) -> AMS Osram (which I don't own), seems like they're co-developing in this area given they randomly went out of their way this year to say HBM <-> optics was a TAM increase for them. TLDR: I see Ayar/Celestial as candidates for SK Hynix's CPO roadmap, then microLEDs being commercialized past gen-1 maybe 2029. (this is all speculation) Just to throw a bone to quantum dot bros, this got cited like 5 times.