Project: Modular, CO2 laser based Splice and Taper Device for high power photonic components

Photonics is one of the key technologies for a green future, since optical power is not only efficiently used in many laser based production processes (laser cutting, welding, scribing, sintering etc.), but can also be supplied almost without loss by waveguiding structures such as glass fibers to the point where it is needed. Telecommunication has long benefited from this fact by transmitting information over the longest distances without significant loss and at the highest data rates. In the last decades the laser has also grown to be a manufacturing tool in standard industrial machining, using higher optical power sources such as diode or fiber lasers. Consequently the need for suitable high performance, high power photonic components is steadily rising and much packaging and assembly research is done within this field. _x000D__x000D_Glass in its various derivates is the base material for these high power components, since it as an optical material (besides it's pure refraction optical properties) exhibits the highest transparency, lowest absorption and thus little damping, which is important for high power due to effects such as thermal lensing (surface changes) and refraction index changes. Glass fibers are therefore the work horse not only in telecommunications, but also in laser machining, in life science devices and medicine - practically everywhere a laser is used as power source. They enable the local distribution of optical power and, at the same time, it's shaping and beam propagation modification. In recent years there has been progress in developing specialty fibers, e.g. with active cores for fiber lasers, with certain mechanical stress distributions for polarization COtainance and with microstructures. _x000D__x000D_In contrast to telecommunication, fibers for high optical power delivery usually have to provide two functionalities besides pure waveguiding: reduction of power density at incoupling interfaces between free space optics (air) and the fiber (glass), and change of numerical aperture for the adaption to connecting free space optics. The first functionality is realized by "end caps", large glass rods that are bonded to the end facet of the fibre and that accepts the incoming optical power at a greater angel and thus with less power density on a greater area than the fiber core facet itself. The second functionality is realized by "tapers", smooth changes of the fiber core and cladding diameter along a certain length of the fiber. Both types of functionalities are most often required in high power fiber components._x000D__x000D_Demand from the laser machining industry for equipment to manufacture these components provide the market basis for the proposed project. CO participant Nyfors Teknologi AB has long been in the business of providing fiber manufacturing devices to customers wordwide and the portfolio up to now includes fiber strippers, cleavers, recoaters and facet testing equipment. Nyfors' market watch reveals that devices for joining fibers to fibers and end caps as well as tapering has become of great interest. The technological basis is already established at Fraunhofer IOF, the RTD performer within the project. Fraunhofer IOF has long been performing research within the field of high power photonic component packaging in close collaboration with the Institute for Applied Physics of the Friedrich-Schiller-University in Jena, Germany, where high power fiber lasers are investigated with world-renowned scientific impact under the supervision of Prof. Andreas Tünnermann. _x000D__x000D_One technology that has been investigated for years on a scientific and laboratory level is the CO2 laser based machining of glass components. The 10 micron wavelength radiation of a CO2 laser is well absorbed by most optical materials and is thus a versatile source for the heating and melting of glass surfaces with local and time restricted energy input. It is also completely contamination free, since the laser is a non-contacting, particle free energy source, which is an advantage compared to other glass melting technologies. Melting of glass by using the CO2 laser now is investigated with respect to joining fibers with fibers, fibers with end caps and fiber tapering. The application point of view within the project is provided by participant Ceramoptec GmbH, a supplier of specialty fibers and assemblies for high and low power photonic components. With it's application market experience Ceramoptec can define the most common, market relevant application cases that should be adressed by the project._x000D__x000D_The goal of the Smart Splice project is to develop a modular CO2 laser based device on industrial level, that serves for a standard set of fiber to fiber, fiber to end cap and fiber taper tasks, easily adaptable to various industrial applications. It will be developed using the process knowledge from Fraunhofer IOF, the industrial machinery set up knowledge from Nyfors and will be tested and verified on applications defined by CeramOptec.

Acronym Smart Splice (Reference Number: 7422)
Duration 01/09/2012 - 31/08/2015
Project Topic A modular, plug-in capable device for the joining and modification of fibers and end caps to assemble high power photonic components will be developed. The basic processing tool is a Carbon Dioxide laser that enables for contamination free, high quality manufacturing.
Project Results
(after finalisation)
CeramOptec worked out a measurement method to qualify the tapers, splicings etc. probes NA and FRD characteristics._x000D_This measurement method is now used for the fiber / cabel production quality assurance._x000D_
Network Eurostars
Call Eurostars Cut-Off 8

Project partner

Number Name Role Country
3 Nyfors Teknologi AB Coordinator Sweden
3 Fraunhofer-Gesellschaft zur Förderung der Angewandten Forschung e.V. Partner Germany
3 CeramOptec GmbH Partner Germany