Neutron and X-ray diffraction studies of optical glasses
Emma Barney, James Towey, Jessica Butterworth, David Furniss and Angela Seddon
Advanced materials research group, Faculty of Engineering, University of Nottingham, NG7 2RD
The molecules in biological tissue strongly absorb specific light frequencies within the mid-infrared (IR) region of the electromagnetic spectrum, 3-25µm wavelength. These
absorptions can be used as "molecular fingerprints" to generate spectral maps of tissue and provide information about the absence or existence of disease, potentially in real-time
and in vivo. Unfortunately, to utilise this technique requires bright mid-IR broadband sources and fibres that are not currently available.
Researchers are the University of Nottingham are currently developing new glasses for optical fibres to produce and transmit the required light spectra. Glass families best suited
for these applications contain heavy metal ions such as tellurites and chalcogenides. However, the compositions are complex, having a range of different coordination environments
and broad bond length distributions. To determine the structure of these glasses, it is necessary to combine the complementary information offered by X-ray and neutron diffraction
and develop new methods of analysing the data. Case studies to demonstrate the benefits of combining these techniques will be presented.