Speaker
Description
Lens-based imaging detectors such as those typically used for MeV X-ray imaging and synchrotron-based imaging suffer greatly from poor collection efficiency, typically recording only ~1% of light emitted by the scintillator. However, spatially periodic, sub-wavelength photonic structures provide a means to modify the emission, transport and outcoupling of photons in a crystal. Nanoscale patterns applied to scintillators have been shown to generate significant enhancement in the intensity of the detected signal.
Here, we present investigation of a range of nanophotonic structures made using different technologies, targeting improvements in lens-based imaging detectors. We present a range of results including synchrotron and lab-based measurements of signal enhancement in excess of 300%, as compared to unpatterned scintillators. In contrast to the blurring effects which would be expected when recording images using scintillators with randomly roughened surfaces, we have found that the highly ordered surface nanophotonic patterns do not necessarily produce a drop in spatial resolution, allowing for high-quality X-ray imaging.
In addition, we present the results of synchrotron experiments carried out using a microbeam X-ray and a partially patterned scintillator, including a remote outcoupling experiment which demonstrates how a small-area pattern emits light more readily than the surrounding scintillator even when the pattern itself is not directly illuminated. These experiments have provided greater understanding of the transport and outcoupling of light in these materials, further elucidating the mechanism of scintillation enhancement and guiding further development.