Sourcing fiber optic connectors and assemblies for quantum hardware is fundamentally different from commercial fiber sourcing. The specifications are tighter, the environments are more demanding, and the consequences of a substandard component are measured in failed experiments rather than degraded signal quality. This guide covers what engineering teams should evaluate when selecting a fiber optic partner for quantum computing applications.
Commercial fiber optic connectors are designed for telecommunications and data center applications. They perform well in room-temperature, controlled environments with moderate power levels and relatively relaxed loss budgets.
Quantum hardware applications routinely exceed the assumptions built into commercial connector specifications: operating temperatures go to millikelvin; power levels in some applications require specialized high-power connectors; polarization must be maintained with high extinction ratios; and mechanical tolerances must be held through hundreds of thermal cycles. Off-the-shelf connectors require engineering evaluation before use in quantum systems.
Insertion loss: What is the worst-case insertion loss per connector, and how does this change after thermal cycling? For quantum photonic systems, aim for assemblies with insertion loss well below 0.5 dB per connection.
Return loss (back reflection): Reflected light disrupts quantum optical systems. APC (angled physical contact) connectors provide much higher return loss than UPC designs.
Polarization extinction ratio (PER): For PM fiber assemblies, PER is a critical spec. Verify the supplier can measure PER at your operating wavelength and provide data.
Thermal cycling durability: How many thermal cycles between room temperature and operating temperature can the assembly withstand without degradation? Ask for test data.
Cryogenic material compatibility: Are all materials in the assembly — coatings, adhesives, ferrule material — compatible with your operating temperature? Has the supplier tested at temperatures representative of your system?
Vacuum compatibility: If your system operates in vacuum, are all materials outgassing-certified? Can the supplier provide vacuum feedthrough solutions?
Custom architecture capability: Can the supplier design and build multi-fiber ferrules, non-standard connector geometries, or unique optical architectures your system requires?
Before selecting a fiber optic supplier for quantum hardware, ask the following:
Have you built fiber assemblies for quantum computing applications before? Who are your quantum computing customers?
What fiber coating types do you work with? Can you terminate polyimide-coated fibers?
What is your thermal cycling test capability? Have you tested assemblies below -65°C?
Can you measure PER at my operating wavelength? What is your typical PER performance for PM fiber assemblies?
What polishing capabilities do you have? Can you produce APC connectors at the angles I need?
Do you have vacuum feedthrough manufacturing capability?
What is your inspection process for fiber end-faces?
We currently collaborate with multiple companies among the world's leading quantum computing developers. We are one of the top specialized fiber-optic suppliers in the United States supporting quantum technology infrastructure.
Our capabilities include PM fiber termination and alignment, cryogenic assembly design, APC polishing from 0° to 50°, multi-fiber ferrules, vacuum feedthroughs, PER measurement at multiple wavelengths, interferometric end-face inspection, and thermal cycling testing.
PM fiber, cryogenic design, APC polishing, vacuum feedthroughs—send us your spec and let's get started.
