Medical Device Laser Marking · Twin Cities, MN
MOPA fiber laser annealing produces a permanent black oxide mark on medical-grade metals. No surface ablation. Passivation layer preserved. Sterilization resistant.
Same-business-day quote response. First article inspection included.
What Is Laser Annealing
Laser annealing uses a precisely controlled pulse to heat the metal surface just enough to form a black iron oxide layer — a permanent color change with no material removed and no surface topology change.
The mark is flush with the surface. The passivation layer is preserved. The part can still be sterilized. That's what makes it the correct process for medical device marking when the OEM specifies it.
Standard fiber laser engraving removes material — it ablates a groove into the surface. That's fine for many industrial applications, but it destroys the passivation layer and creates crevices where bacteria can harbor. It does not meet medical device marking requirements when annealing is called out.
| Standard Fiber Engraving | MOPA Annealing | |
|---|---|---|
| Material removed | Yes | No |
| Passivation layer | Destroyed | Preserved |
| Surface topology | Groove/crater | Flush — no change |
| Sterilization resistant | Questionable | Yes |
| UDI compliant | Depends on spec | Yes |
| Biocompatible mark | No | Yes |
Why MOPA Matters
True laser annealing requires precise nanosecond pulse control — the kind only MOPA (Master Oscillator Power Amplifier) technology delivers. Standard fiber lasers and CO2 lasers lack this control. They can produce a dark mark, but they can't produce a compliant annealed oxide layer without either removing material or inconsistently hitting the target thermal threshold.
If your drawing calls out laser annealing, a standard fiber laser shop cannot execute it to spec. MOPA is the requirement — not a preference.
Materials We Anneal
Laser annealing is specific to metals that form an oxide layer under controlled heat. It is not applicable to aluminum, plastics, or non-passivatable materials — for those, we use other MOPA marking processes.
Applications
Forceps, retractors, clamps, and other reusable instruments requiring permanent marking that survives repeated autoclave sterilization.
Bone screws, plates, and joint components where UDI marking must be biocompatible and the surface must not harbor bacteria.
Housings, brackets, and sub-assemblies in stainless or titanium where part traceability is required and the mark must not compromise the surface.
When the drawing specifies "laser anneal" or "black oxide laser mark" — this is exactly that process, executed to spec.
Get a Quote
Tell us about your part and upload your drawing, spec sheet, or SOLIDWORKS file. We'll confirm the process and get you a quote the same business day.
Prefer to call? (612) 446-5488
