The Photonic Quantum Stack — Lasers, Modulators & Single-Photon Detectors
Photonic and trapped-ion quantum computers don't need fridges. They need very specific lasers and detectors — a near-monopoly held by a handful of optics firms.
Two qubit architectures avoid the millikelvin requirement: trapped-ion (used by IonQ and Quantinuum — atoms suspended in electromagnetic traps, manipulated by lasers) and photonic (used by PsiQuantum and Xanadu — qubits encoded directly in photons of light). Both need exquisite optics: tunable lasers with sub-nanometer wavelength precision (Coherent, Lumentum), CW lasers for cold-atom cooling , optical modulators , and single-photon detectors — the latter is a near-monopoly held by Hamamatsu Photonics in Japan.
These optics companies primarily serve other end markets (AI optics, industrial lasers, medical imaging) — but quantum is the highest-spec, highest-margin sliver of their business. They benefit from quantum scaling regardless of which architecture wins, with full downside protection from their core industrial businesses.
4 names on the watchlist
Pre-eminent supplier of specialty lasers for trapped-ion quantum (IonQ, Quantinuum) and silicon-photonic quantum. Also #2 globally in SiC wafers.
The combined Coherent + II-VI entity following the 2022 merger. Makes tunable lasers, modulators, optical components for AI datacenter optics, industrial laser cutting, displays, and increasingly quantum computing. FY-Q3 revenue $1.81B (+21% YoY). Per Coherent's March 2026 8-K (Stocktitan/SEC): NVIDIA invested $2 billion via a direct equity placement of 7,788,161 new common shares at $256.80 each, alongside a multi-billion-dollar multiyear purchase commitment — a major strategic anchor for AI optics.
Optical Circuit Switches (OCS) for AI training fabrics. Q2 FY26 revenue $665.5M (+66% YoY). Minor quantum exposure.
Maker of laser diodes and optical components . Primary exposure is AI optics (the lasers that move data inside datacenters at the speed of light). Optical Circuit Switches (OCS) for AI training fabrics is the new growth engine. Q3 FY26 guide $780-830M; OCS backlog over $400M. Quantum exposure is minor today but growing.
Dominant single-photon detectors (SPADs, SNSPDs) and PMTs. The default detector for photonic-quantum and quantum-key-distribution.
Japan-listed. Dominant supplier of single-photon avalanche diodes (SPADs), superconducting nanowire single-photon detectors (SNSPDs), and photomultiplier tubes (PMTs) . These are the only detectors that can count individual photons — required for photonic quantum computing, quantum key distribution, low-light scientific imaging, and LIDAR. Near-monopoly in single-photon detection. Quantum-specific exposure that you can't get any other way as a public investor.
Fiber lasers — primarily industrial cutting/welding. Defense laser programs growing. Quantum exposure minor.
Industrial fiber-laser leader. Quantum exposure is marginal — included for completeness. Defense laser programs are the bigger driver than quantum. Less of a chokepoint than the names above.
- Business Research Insights, AAAS · May 2026