Fiber-based Stray Light Suppression in Spectrometers

Abstract: Stray light is known as strong interference in spectroscopic measurements. With the creation of a novel kind of customized fibers, manufactured by the fiber optics group in Jena, Germany, a general experimental solution to this problem is possible. This thesis work is mainly aiming at testing and demonstrating how these fibers work for stray light suppression and their efficiency in measuring different types of optical signals. It is here demonstrated that the method is capable of stray-light suppression to more than one order of magnitude in Raman spectroscopy. In addition, studies of emission from Argon atoms show that the fiber is a good solution for suppression of background and high-frequency noises, which is reduced by more than a factor of 3 and 5, respectively. The results show that the method is feasible and efficient in practical use and that it has potential as a further tool in spectroscopy.