Light scattering in absorbing ceramic suspensions: Effect on the width and depth of photopolymerized features

Light scattering in photopolymerizable ceramic suspensions affects the resolution of photopolymerization processing methods; it is necessary to predict the cure width and cure depth at a given energy dose for a suspension with a known composition. The volume fraction of ceramic powder in the suspension or the refractive index (RI) contrast between the ceramic powder and the liquid solution was varied, measuring the quasi-Beer-Lambert suspension properties. For these suspensions, the depth and width attenuation and the depth and width critical energy doses were determined. The volume fraction of powder has no effect on the broadening depth; the solids loading can be varied without concern for increased scattering within the suspension. The broadening depth decreases with the logarithm of RI contrast. Suspensions with a small RI contrast are able to cure deep, narrow features without broadening.