The Science & Technology
Cambridge - Monday 4th to
Wednesday 6th September 2017
article posted 21 June 2017
Xu Yang is currently working on his Ph.D. in Otto-Schott Institute for Material Research. He received his bachelorís degree from Wuhan University of Technology in optical information
science and technology in 2009. He received his masterís degree from Friedrich-Schiller University of Jena in Physics-photonics in 2017. His research interests focus on the novel functions of
optical fiber, material science, optical microscopy and spectroscopy. He helped develop the code of 3D data representation of bacterial in Single-Molecule Microscope group in University Jena.
He helped design and realize an instrument for measuring the homogeneity factors of glasses by Christiansen-ShelyubskII method in Otto-Schott Institute for Material Research.
Structural Anisotropy in Hybrid Waveguide
Xu Yang*, Garth Scannell, Markus A. Schmidt, Lothar Wondraczek
Otto Schott Institute of Materials Research
Leibniz Institute of Photonic Technology
Metaphosphate glasses consist of long polymeric chains which have a high degree of flexibility. They also have low glass transition temperatures making it easy to deform them. By applying
an external force, such as drawing a fiber or pushing into a small capillary, structural anisotropy can be generated in phosphate glasses, creating a preferential orientation of chains in the glass.
This structure contributes to anisotropy of physical, chemical and mechanical properties. This makes metaphosphate glasses an ideal material to study in the investigation of how changing the
experimental parameters affects the anisotropy of a filled capillary.
In this study, the effects of changing temperature, pressure, filling time, and capillary diameter during pressure assisted melt filling (PMAF) on the anisotropy of a silver metaphosphate
glass were investigated. The degree of anisotropy was estimated at five points on each sample using polarized Raman spectroscopy. The acquired spectra were pre-processed and fitted with Lorentz
functions. By collecting Raman spectra polarized parallel and perpendicular to the filled capillary an estimate of the anisotropy can determined from the change in the ratio of the peak intensities.
This is done by calculating the area ratios between two main peaks in each polarization direction. Afterwards, the division between two polarization directions are compared at different experimental
conditions to examine the overall dependency of the anisotropy on each parameter. Anisotropy was observed to increase linearly with increasing pressure, to decrease with increasing filling time, and
remain relatively constant with increasing temperature or capillary diameter.