Jason's Chips
Buy-Side AI & Semiconductor Investor
Lumentum, the largest indium phosphide laser maker and supplier of the ultra-high-power laser in NVIDIA's Spectrum-X CPO switch, has a lot to gain from the silicon photonics roadmap. Its indium phosphide is sold out for years, which explains why its SEMICON Taiwan talk promoted gallium arsenide VCSELs for scale-up, rating them strong on 5 of 7 axes. VCSELs are its only incremental revenue in that period, even though they could displace its InP business. x.com x.comÂ
Lumentum's DWDM external laser source makes silicon photonics scale-up and scale-in designs far more competitive against microVCSEL and microLED approaches. It packs eight lasers, each on its own wavelength, into one fiber instead of eight separate ones, cutting fiber count by a factor of eight. x.comÂ
Optics and photonics should be among AI's biggest winners as faster GPU networks need optical connections that suppliers cannot expand quickly enough. Lumentum says some components are sold out through early 2029; Sivers is investing $30M to target more than 100M lasers a year, with operations expected in Q4 2027. Potential US restrictions on Chinese transceivers could reshape supply in 2027. Applied Optoelectronics and Sivers are the favorites. x.com x.comÂ
Marvell risks paying a peak-scarcity price for Lumentum if optical supply catches up by 2028-30. The proposed ~$99B deal values Lumentum at roughly 20x guided annualized revenue and 58x estimated after-tax operating income, while Lumentum, Coherent and Chinese suppliers are adding laser capacity. The DSP-and-laser combination has strategic logic, but durable scarcity economics and Nvidia's response remain uncertain. x.comÂ
VCSEL scale-up optics may spread revenue across more suppliers because they lack the fundamental bottlenecks of InP lasers. Coherent looks well positioned, but the VCSEL opportunity may still be shared more widely; Lumentum is also betting on VCSELs for scale-up. x.comÂ
Lumentum is the only volume supplier of EML lasers for 1.6T optics, capacity is sold out, and indium phosphide fabs do not scale overnight. Qualcomm and Corning partnered with it on 1,060nm VCSEL chip-to-chip links targeting about 10 Tb/s. Revenue grew 109% and it trades at 30.6x forward earnings with $1.07B of net cash; a one-time $7.8B non-cash convert charge hid profitable operations. Risks are convert dilution and Coherent and Broadcom adding InP lasers before the shortage eases. x.comÂ
Lumentum stands to gain as the shift from copper to light inside AI data centers accelerates. Co-packaged optics is now in mass production, per TrendForce, with Nvidia shipping Spectrum-X CPO switches. Near-packaged optics is catching on fast; Lumentum CEO Michael Hurlston says its demand looks bigger than CPO's and came sooner, now late 2027 or early 2028. He sees about $40 a share of fiscal 2028 earnings power, above Street estimates, with none of CPO or NPO in the numbers yet. x.comÂ
Wafer-tested VCSEL arrays could erode Lumentum's laser scarcity premium if scale-up links adopt wide, parallel designs. Lumentum's in-rack demo used arrays but does not replace every high-power laser; Credo and ams OSRAM seek approval for a parallel-link standard in 2027. Multiple suppliers would pressure pricing power and margins. Near-term earnings could still benefit from laser shortages, with Lumentum sold out through early 2029. x.comÂ
AI bandwidth demand still favors Coherent and Lumentum, but tight customer financing can delay orders and lasting valuations need durable profits. A model provider losing share need not reduce total bandwidth use. Coherent could beat and raise guidance; Lumentum may only meet estimates this quarter, improving next quarter. If margins partly reflect scarce indium phosphide, added supply will test whether upgrades, volume and cost gains sustain earnings. These earnings calls remain forecasts. … Show more
Lumentum's Raman pump lasers could benefit as more inter-site AI network spending shifts to optical line systems. Cignal AI forecasts those systems taking 57% of this spending by 2030, up from 29% in 2026, and identifies Raman amplification as a major cost driver and pump lasers as one of the tightest supply-chain components. Lumentum offers those lasers and the amplifiers built around them. x.comÂ
Lumentum and Coherent face a threat from microLED optics, which could replace laser optics with 20x less power and no temperature sensitivity by late 2027. The use case is short-reach, high-volume links under 30 meters. The copper versus optics debate is a distraction, since every AI cluster needs both and Credo now does both while Applied Optoelectronics handles long-haul; the bigger question is what microLED does to laser makers. x.com x.comÂ
Photonics suppliers ride the same curves Marvell just laid out through 2030. Marvell targets $70-90B of fiscal 2031 revenue from $8.2B last year, with a TAM 4x its last investor day and interconnect the biggest segment at about $37.5B. Supply is tight: Lumentum's CEO says it can meet only 30% of customer demand next year, and Coherent is booked through 2027. @AsymmetricBets_ applied Marvell's model to Lumentum, Coherent, Applied Optoelectronics, Ciena, Tower Semiconductor and Astera Labs. x.comÂ
