The Science & Technology
of Glass
Cambridge - Monday 4th to
Wednesday 6th September 2017

Aaron Reupert
<[email protected]>

article posted 17 Apr 2017

Aaron Reupert currently is a PhD candidate at the Laboratory of Glass Science with Prof. Dr. Wondraczek where the focus of his work is on the side emission of fibers. He holds a German diploma in physics from the Friedrich Schiller University of Jena and wrote his thesis and published research on ion beam induced stress formation and relaxation in germanium.

Side-Emitting Fibers:
Coupling Guided Modes to Radiation Modes in Optical Fiber
via Fs-Laser Induced Microstructures
Aaron Reupert1*, Jörg Schneider1, Lothar Wondraczek1
Maximilian Heck2, Stephan Nolte2

This paper investigates the possibility of coupling energy from guided optical fiber modes to free space radiation modes by means of laser written scattering centers in the core of an optical fiber. Such side emitting optical fibers are used for diverse illumination purposes, including functional illumination, for example, in endoscopic diagnostics or phototherapy. One aspect of great relevance comprises coupling the light guided by the optical fiber to radiation modes while avoiding the coupling to cladding modes. Furthermore, the resulting angular radiation pattern might be of interest for the desired application, e.g., uniform environmental illumination which implies Lambertian emission.

So far, little research has been conducted on the actual angular distribution of side-emitted light and on the efficient coupling to free space radiation. We argue that this is due to the lack of a practical investigation method. Therefore, here, we introduce the technique of leakage radiation microscopy - or Fourier microscopy - to probe the processes of light scattering on microstructures. Exemplarily, we consider features which were created on optical fiber by focused femtosecond (fs) laser beam irradiation for direct imaging of the angular spectral distribution of scattered light.


1: Otto Schott Institute of Materials Research, Friedrich Schiller University, Frauenhofer Straße 6, D-07743 Jena, Germany

2: Institute of Applied Physics, Friedrich Schiller University, Albert-Einstein-Straße 15, D-07745 Jena, Germany