j-fiber -
Our products connect people worldwide

j-fiber GmbH is one of Europe’s leading suppliers of optical fibers for data transmission and the only industrial-scale manufacturer of optical fibers for telecommunications in Germany.


As a leading specialist for multimode fibers, j-fiber offers its customers a broad-based portfolio of services for standards-compliant, high-performance multimode fibers – from OM1 to OM5 multimode fibers.

Multimode product portfolio




In order to meet the rising demand for singlemode fibers for broadband expansion in Europe, in 2019, j-fiber formed the joint venture “j-fiber Hengtong GmbH” with the Hengtong Group and established new production capacities at its Jena facility for singlemode fibers “Made in Germany”.

Product portfolio singlemode


G.657.A1 (250 µm/200 µm)

G.657.A2 (250 µm/200 µm)

Special fibers

j-fiber is a leading specialty fiber manufacturer for innovative application fibers, custom specialty fibers and modified standard fiber options.

Product portfolio specialty fibers

Special fibers for high-temperature applications (multimode and singlemode)

Radiation hardened fibers (multimode and singlemode)

QPL-listed fibers (multimode and singlemode)

Fibers with 500 µm coating (singlemode and multimode)

Selected cut off singlemode fibers

Multicore fibers


High-quality preforms form the basis for manufacturing and deploying high-performance special and standard fibers. Thanks to our understanding of the performance parameters required of the final product and the methods of influencing these at each stage of the manufacturing process, we can create the perfect product to match your individual requirements.

Specification of design and configuration of the preform in terms of core profile (step index or gradient index) and doping (e.g. phosphorus) to achieve the desired numerical aperture.

Consideration of the required geometry of the preform for the core and sheath to enable application-specific assembly according to your requirements