New algorithm speeds up material testing for coatings and optical products
Researchers have developed a faster computational method to measure how light scatters and absorbs in industrial materials like titanium dioxide and metallic suspensions. The technique cuts analysis time and cost compared to existing approaches, potentially accelerating product development cycles in manufacturing sectors that rely on precise optical property characterization.
Originaltitel: Determination of intrinsic scattering and absorption coefficients of light diffusing materials: application of a spectral projected gradient method
<p>We explore a novel method to obtain scattering and absorption (S&A) coefficients of inhomogeneous materials from measurements of regular transmittance and specular reflectance. We use a Spectral Projected Gradient Method (SPGM) to invert experimental spectra. The SPGM method requires an initial approximation to the S&A coefficients, which is needed to ensure convergence to an optimized solution. We discuss problems associated with multiple solutions and conditions for the obtained optimal solution to be a good approximation to the physical one. We present results for TiO<sub>2</sub>/polyvinylpyrrolidone (PVP)-water, plasmonic Au/PVP-water and ferromagnetic Fe<sub>3</sub>O<sub>4</sub>/PVP-water materials. The obtained S&A coefficients indicate that these materials are dilute suspensions of dense particle clusters in the dependent scattering regime. We argue that the SPGM gives physically realistic solutions for this class of materials. The SPGM has the advantages that it is much less expensive in computational terms and easier to implement than previously used simulated annealing methods.</p>