Equipment and capabilities

Our devices for fiber micromachining, 3D nanoprinting, and precision cleaving and splicing of optical fibers.

Glass micro-machining by CO2 laser ablation

By local thermal evaporation of glass with a focused CO2 laser beam, tiny dimples can be machined into various glass substrates. Due to the momentary melting of the glass, the surface of these depressions becomes smooth and symmetric. In this way, mirror shapes with small radii of curvature (~100 µm) can be produced directly on the end faces of cleaved optical fibers. After applying a high-reflective coating, fiber cavities of finesse up to 100 000 can be assembled.

1/2 End face of an optical glass fiber (diameter 125 µm) before (left-hand image) and after (right-hand image) creation of a concave mirror surface by laser ablation. Image produced by interference microscope. © Michael Kubista / Universität Bonn

2/2 Process for micro-machining of fiber end faces by CO2 laser ablation for fabrication of miniaturized optical fiber resonators. © Wolfgang Alt / Universität Bonn

3D direct laser writing system

By two-photon polymerization of a lithographic resist, arbitrary three-dimensional structures can be printed with resolution of ~100 nm. Examples are lenses on optical fibers, complex 3D coating masks, optomechanic membrane stacks, dielectric waveguides, and miniature mounts for optical fibers.

3D direct laser writing system “Photonic Professional GT” by Nanoscribe GmbH © Florian Giefer / Universität Bonn

Fiber splicer and cleaver

For precision cleaving and splicing of single-mode, polarization-maintaining, multi-mode, and GRIN fibers, including splicing of dissimilar fibers, state-of-the-art fiber cleavers and splicers are available.

1/2 Fiber splicer. First, two cleaved fibers are precisely positioned by the device such that their cores lie on a common axis. Then an electric arc heats and melts the glass at the fiber end facets, and the two fiber ends are pushed together such that the molten glass fuses the two fibers. © Wolfgang Alt / Universität Bonn

2/2 Here, short pieces of graded-index and multimode fibers, only fractions of a millimeter long, have been spliced onto a single-mode fiber. Fiber lengths deviate from the specified values by less than 5 μm. With this setup, mode matching between fiber resonator and singlemode fiber can be significantly improved, maximizing optical coupling efficiency. © David Röser, Wolfgang Alt / Universität Bonn

Plasma asher

A plasma asher is available for the removal of organic materials from surfaces. It can also be employed for post-processing (surface smoothing, structural thinning) of polymer structures created by 3D direct laser writing.

Plasma asher in operation: A strong radio-frequency (RF) electromagnetic field excite a low-pressure, oxygen-containing gas into a pink-glowing plasma. The window has an embedded metal net to keep the RF fields inside the device. © Stefan Linden / Universität Bonn