Increased Light Extraction From Inorganic Scintillators With Laser-Etched Microstructures

A technique of laser-etching repeating micrometer-scale structures into the exit surface of a thin, YAP:Ce scintillator to increase light extraction has been performed. Different etching techniques were performed on a single, monolithic crystal using varying laser power to study how light extraction is influenced by these different treatments. For the best case, a 90.4% increase in light extraction was measured without optical coupling, which compares to photonic crystal techniques. This technique finds application in associated particle imaging (API) where no optical coupling can be used for the alpha detector's scintillator, inside the Deuterium-Tritium (D-T) neutron generator vacuum. The surface characteristics of each treatment are quantified, and changes in light collection relative to a normal, polished surface are presented. Measurement of the number of detected photons is given for the case where no optical coupling is used between the scintillator and photosensor. Additionally, implications of performance improvements in YAP:Ce based alpha transducers within D-T generators, due to the measured increases in light collection, are presented.