Implementation of Photonic Crystals into Davis LUT module for GATE simulation

Area of Science:

• Medical Physics
• Materials Science
• Optical Engineering

Background:

• Positron Emission Tomography (PET) detector performance is limited by optical photon collection efficiency.
• Photodetector collection is restricted by the critical angle for photons exiting the scintillator.
• Photonic Crystals (PhCs) offer a potential solution by manipulating light propagation beyond the critical angle.

Purpose of the Study:

• To develop and validate a simulation model for incorporating Photonic Crystals (PhCs) into PET detector simulations.
• To evaluate the impact of PhCs on optical photon harvest in lutetium oxyorthosilicate (LSO) scintillators coupled with titanium dioxide (TiO2) PhCs.
• To investigate the angular distribution of collected photons for optimizing photodetector design.

Main Methods:

• Generalized the GATE optical model by integrating a PhC optical model into the LUT Davis model.
• Simulated LSO scintillators (3x3 mm² to 10x10 mm², 9-18 mm thickness) with PhC interfaces.
• Tested four PhC configurations and compared optical photon harvest and energy resolution to traditional coupling.

Main Results:

• Achieved up to a 62.4% improvement in optical photon harvest with PhCs compared to traditional coupling.
• Observed variable performance across different PhC structures.
• Noted only slight improvements in energy resolution, prompting further investigation into photon angular distribution.

Conclusions:

• The generalized LUT Davis model enables simulation of advanced scintillator detectors with PhCs.
• PhCs significantly enhance optical photon harvest in PET detectors, with optimal configurations yielding substantial gains.
• Understanding photon angular distribution is key to maximizing photodetector efficiency and further improving PET imaging.