Polarized Raman Mapping Method for Estimation of Refractive Index Differences on Grain-Boundaries and Inline Transmission for Well-Sintered Translucent Alumina

Abstract

In this study, polarized Raman mapping technique was applied to determine the orientations of c-axis of each grain in translucent polycrystalline alumina samples which were well-sintered in H2 atmosphere. The averaged refractive index difference Δnavg between neighboring alumina grains was experimentally estimated from the mapping data. It was demonstrated that the translucent alumina had Δnavg of ~0.002, smaller than the random value in the Apetz et al model (ΔnApetz = 0.0053). With the experimental value, then light transmission spectra was simulated in the scope of the well-known Rayleigh-Gans-Debye (RGD) theory.