Resonant Metasurface-Mediated Light Output of Barium Fluoride Scintillators: Design and Simulation

Barium fluoride (BaF₂) crystals are known for their applications in high-energy physics (HEP) experiments due to their ultrafast scintillation component. However, the slow scintillation component with high light yield presents challenges in high-rate applications. To enhance the performance of BaF₂ crystals, the fast and slow components should be enhanced and suppressed, respectively. This article introduces a novel approach to mediate the luminescence of BaF₂ crystals using a resonant metasurface, composed of a double-layer pillar array with a high refractive index (RI) contrast. The metasurface induces localized optical resonance to reduce transmittance of the slow component while utilizing whispering gallery modes (WGMs) and Bragg diffraction to enhance the fast component. The performance of the resonant metasurface is further improved by resonant mode engineering. The effectiveness of resonant metasurface in mediating BaF₂ luminescence is demonstrated through simulations, providing insights into potential applications in HEP experiments. In addition to the applications on the scintillators, we anticipate that such approach to simultaneously mediate light with different wavelengths could be expanded to other important fields, such as full-color display, light emitting diodes, and solar cells.