Lateral Fiber Cladding Processing
A new laser-based method for lateral processing of optical fibers is presented, which can be used for controlled material removal. This method allows the non-hazardous fiber component fabrication without etching and mechanical processing.
Challenge
For the fabrication of different fiber optic components, like for example signal-pump-combiners, it is necessary to expose the light guiding structure of the fiber. Depending on the fiber type e.g. specialty fibers like chirally-coupled-core or triple-clad fibers, the outer material has to be removed to build efficient fiber optic components. Previous methods for processing fibers are based on removing material by etching with hydrofluoric acid or mechanically removing of material by grinding/polishing. The disadvantages of these methods are the reduction of optical quality, the need of hazardous substances and restrictions in the flexibility of the process zone. For these reasons, the processes are not suitable for mass production of fiber components. Therefore, fiber laser or amplifier systems based on specialty fibers often rely on free space coupling of the pump power. The method presented here allows for the first time a fully fiber-integrated solution.
Our Solution
Our solution is a new method for lateral processing of the glass or polymer cladding of a fiber using a laser beam to remove the cladding or to improve the surface quality.
Fig. 1: Schematic representation of lateral processing of a fiber using a CO2-laser.
During the processing the fiber is rotating. Glass material is selectively removed and the fibers surface is melted several times by repeated lateral movement of the laser beam during rotation, thereby achieving an excellent quality of the glass surface. In the transition areas between unprocessed and processed areas, the laser beam is moved away from or towards the fiber to create an adiabatic transition. Surface roughness studies have shown that the surface produced is suitable for the manufacture of fiber components.
Fig. 2: Measured roughness profile (Keyence VK-1100) shows high surface quality.
Advantages
- Flexible process zone, adjustable by the laser power and lateral processing method
- Process automation possible
- Excellent surface quality
- Non-hazardous
Applications
- Fiber component production
- Manufacturing of splice less fiber systems
Development Status
The feasability of the process has been successfully demonstrated in the manufacturing process for fiber couplers based on chirally-coupled-core speciality fibers.
Patent Status
Laser Zentrum Hannover e.V.
DE102021103603B4 (granted)
PCT/DE2022/200016 (filed)
Weiterführende Informationen (in h2)
Brockmüller et al. 2022; Vol. 30, Issue 15, pp. 25946-25957
Kontakt
Dr.Maria Kamper
Patent Manager Physics / Technology
E-Mail:This email address is being protected from spambots. You need JavaScript enabled to view it.
Tel.: +49 551 30724 159
Referenz: CPA-2286-LZH
Image Source: Fabian Kranert Laser Zentrum Hannover e. V.
Tags: Laser physics and optics
