
German manufacturer of custom fiber optic cables, fiber bundles, optical sensors and photonic assemblies.

FOS Inon Optics GmbH
Siegen · AßlarNew on Amplifa
About FOS Inon Optics
FOS Inon Optics is a owner-managed, medium-sized manufacturer of custom fiber optic cables and fiber bundles headquartered in Niederschelden-Siegen. The company produces fibers with core diameters from 10 to 2400 µm, custom fiber optic assemblies, flexible light guides, fiber optic probes for flame monitoring, and PAT fiber optic sensors for inline spectroscopy. The portfolio is complemented by engineering services (optical design, simulation, optomechanical design), CNC parts, laser marking, technical 3D printing for prototypes, LED lighting solutions, as well as OEM manufacturing and rapid prototyping for medical devices. Customer industries include medical technology, analytics and spectroscopy, pharmaceuticals and biotechnology, process analytics, power plants and energy technology, aerospace, and laser and lighting applications. Production is carried out in accordance with ISO 9001:2015 at the Siegen and Aßlar sites; the company operates its own fiber manufacturing facility with a fiber drawing tower, preform oven (2000 °C), coating extruder and diameter measurement. Mechanical precision components are manufactured with eccentricity deviations below 15 µm.
- Site
- Siegen
- Processes
- Fiber optic cables and fiber bundles (custom fiber assemblies), Eccentricity precision of mechanical components, Optical sensor technology / fiber optic sensor heads, Fiber optic probes for flame monitoring, PAT probes / fiber optic sensor technology for inline spectroscopy, Laser marking, CNC parts, Technical 3D printing for prototypes
- Materials
- Borosilicate (boron glass), PMMA (polymethyl methacrylate), Silica Hard Clad, Silica-Silica (UV & NIR), Quartz / fused silica (SiO2), Germanium-doped fiber, Fluorine-doped fiber, Polyimide (jacket)
- Certificates
- ISO 9001:2015, ISO 9001, ISO 14001, ISO 13485
- Industries
- Medical technology & aesthetic medicine, Analytics & spectroscopy, Pharmaceuticals & biotechnology, Process analytics (PAT) / Industry 4.0, Food & beverages, Power plants / energy technology
- 01
Fiber manufacturing (preform, drawing, coating)
- 02
Fiber assembly and bundle production
- 03
CNC machining and laser marking
- 04
Assembly of assemblies and probes
- 05
Quality control and testing
Locations

Siegen
DEProduction site and legal seat (Niederschelden-Siegen)
- Lot size
- Prototype to series
- Materials
- Borosilicate, PMMA, Silica Hard Clad, Silica-Silica
- Fiber drawing tower (preform, oven 2000 °C, coating extruder, diameter measurement)
Aßlar
DESite for engineering, manufacturing, QM and development
- Lot size
- Prototype to series
- Materials
- Silica, borosilicate
Components and Products



Inside the production

Industries
Processes & technical limits
| Processes | Tolerance | Max. part | Weight | Lot size | Materials |
|---|---|---|---|---|---|
| Fiber optic cables and fiber bundles (custom fiber assemblies)Joining | – | 20 m (fiber optic probes) | – | – | Borosilicate, PMMA, Silica Hard Clad, Silica-Silica |
| Eccentricity precision of mechanical componentsMachining | Eccentricity deviations < 15 µm | – | – | – | – |
| Optical sensor technology / fiber optic sensor headsEngineering | – | – | – | – | Borosilicate, Silica-Silica |
| Fiber optic probes for flame monitoringAssembly | – | 20 m | – | – | Silica, Borosilicate, Steel (steel braiding), Silicone |
| PAT probes / fiber optic sensor technology for inline spectroscopyEngineering | – | – | – | – | Quartz, Specialty glass |
| Laser markingSurface | – | – | – | – | – |
| CNC partsMachining | – | – | – | – | – |
| Technical 3D printing for prototypesAdditive | – | – | – | – | – |
| Engineering services (photonics engineering, optical design, CAD design, laser modules,Engineering | – | – | – | – | – |
| Optomechanical assembly manufacturing (lens holders, mirror mounts)Machining | tight tolerances | – | – | – | – |
| OEM manufacturing of medical systems / rapid prototypingAssembly | – | – | – | – | – |
| Fused / welded fiber bundle tipsJoining | – | – | – | – | Silica, Borosilicate |
| In-house fiber manufacturing (preform, oven 2000°C, coating, extruder, diameter measurement)Plastics | Øcore = ±2% | – | – | – | Fused silica/quartz (SiO2), Germanium-doped, Fluorine-doped, PMMA |
| Ferrules and connectors (SMA, FC, ST)Assembly | – | – | – | – | – |
| Quality control & testing (independent in-house QC)Inspection | – | – | – | – | – |
| LED lighting systems / light guides (projectors, strip lighting, starry sky)Assembly | – | – | – | – | PMMA |
1 Anlagen & Maschinen
| Machine | Manufacturer / model | Quantity | Working area | Year built | Site |
|---|---|---|---|---|---|
| Fiber drawing tower (preform, oven 2000°C, coating extruder, diameter measurement) | – | – | – | – | Siegen |
Additional services
Quality
The processes in the development and manufacture of fiber optic systems are certified to ISO 9001:2015. An independent in-house quality control verifies compliance with the technical drawings; ISO 14001:2015 and ISO 13485:2016 are targeted for the future.
| Evidence | Siegen | Aßlar |
|---|---|---|
| ISO 9001 | ||
| ISO 14001 | ||
| ISO 13485 |
History
- 2024
ISO 9001:2015 certification less than two years after the company was founded; announcement of pursuing ISO 14001:2015 and ISO 13485:2016 in the future