Exploring light confinement in laser-processed LYSO:Ce for photon counting CT application.

Exploring light confinement in laser-processed LYSO:Ce for photon counting CT application.
Phys Med Biol. 2019 Mar 21;:
Authors: Blackberg L, Sajedi S, Mandl S, Mohan A, Vittum B, El Fakhri G, Sabet H
Abstract
With the goal of developing a low-cost scintillator-based photon counting detector (PCD) with high dose efficiency suitable for CT, the light transport characteristics in LYSO:Ce detectors containing Laser Induced Optical Barriers (LIOB) are simulated. Light confinement and light collection efficiencies (LCE) are studied for a variety of optical barrier patterns and properties (refractive index (RI) and barrier/crystal interface roughness). Up to 80% confinement is achievable with a simple pixel pattern with one barrier wall separating each pixel coupled one-to-one to a photodetector (PD) pixel. Confinement is heavily dependent on barrier properties, and rough interfaces and higher RI results in increased cross-talk. Three approaches to enhance performance beyond the basic pattern are explored: 1) Multiple barrier walls separating each crystal pixel. 2) Introduction of long and short range confinement by having multiple crystal pixels per PD pixel. 3) Combination of LIOB and Laser Ablation. 1) Is effective for rough interfaces where confinement can be increased by up to 24% for double compared to single walls. 2) Results in high confinement in the pixel centered on the PD pixel, but lower confinement closer to the PD edge. This...

Source: Physics in Medicine and Biology - March 20, 2019 Category: Physics Authors: Blackberg L, Sajedi S, Mandl S, Mohan A, Vittum B, El Fakhri G, Sabet H Tags: Phys Med Biol Source Type: research