Accurate characterization of phantoms for performance assessment and calibration in diffuse optics

We developed refined methods for time-domain measurements of the optical properties of solid homogeneous turbid phantoms. Employing a reliable time-domain reference setup with a stable, narrow, and clean instrument response function and GPU-based Monte-Carlo fitting, 1% accuracy for optical properties seems realistic. An alternative space-enhanced time-domain method that combines spatially resolved amplitude with a time-domain measurement effectively reduced the crosstalk between absorption and scattering. Besides physical phantoms, we explored and characterized a digital phantom that mimics arbitrary time-of-flight distributions via time-dependent attenuation employing a spatial light modulator and a dedicated multi-fiber delay unit. We discuss potential applications in performance tests.