Optical Attenuation and Cure-Profile Physics in Particle-Filled Vat Photopolymerisation: Absorption, Scattering, Refractive-Index Contrast and Feature Broadening
Segurola, Juan
2026-08-27 · Report · Version 1.1
Particle-filled resins support ceramic, conductive, dental, optical and structural functions, but the same dispersed phase that creates functionality also changes how light propagates and how the cure boundary develops. This review separates absorption, forward transmission, multiple scattering and side-scattered polymerisation, then links them to powder volume fraction, particle size distribution, morphology, agglomeration, refractive-index mismatch, matrix composition, photoinitiator and absorber content. It adopts the source-defined depth sensitivity, depth critical energy, width sensitivity, width critical energy, excess width and broadening depth as reporting variables rather than universal material constants. The literature shows that the effect of fillers is not monotonic: opaque or highly mismatched particles can reduce penetration, low refractive-index contrast can suppress broadening, and translucent glass microspheres can increase cure depth at low exposure because transmission competes with scattering. Resin composition, filler dispersion and particle-size distribution can shift cure depth and lateral growth in opposite directions. A minimum qualification matrix is proposed that records the optical spectrum, incident pattern, depth and width profiles, conversion, gel criterion, filler state, rheology, ageing and printed geometry. The review does not prescribe a universal filler loading, attenuation coefficient or cure target and does not infer final ceramic, electrical, dental or biological performance from optical printability.