Modeling the effects of scattering and absorption on the transmission of light in polycrystalline materials

Abstract

As transparent polycrystalline materials become more important in optical applications, evaluation of their optical properties across a wide range of wavelengths (or frequencies) is crucial for device design. In-line transmission measurements are often used to assess the suitability of materials for a given optical application. We developed a model that describes reflection, scattering, and absorption losses that commonly affect transmission. The model demonstrates the effects that parameters such as absorption type (Lorentzian or Gaussian), scattering regime (Raleigh–Gans–Debye or Rayleigh), and optical path length have on transmission spectra. We also fit the model onto transmission data from three polycrystalline material systems: ruby, yttria stabilized zirconia, and terbia. Parameters extracted from these fits can be used to describe wavelength dependent transmission with one simple analytical expression. The fit can also be used to decouple absorption from scattering, allowing for the extraction of important properties such as absorption coefficients.

Ultratransparent PMN‐PT Electro‐Optic Ceramics and Its Application in Optical Communication

“…The total in‐line transmission given by Shachar et al. is expressed as below [ 21 ] where T is the total in‐line transmission, T R is theoretical transmission when only reflection loss at both surfaces is considered, R s is the reflection loss due to a single surface, n is the refractive index of transparent ceramics, T RGD is the transmission resulting from Rayleigh–Gans–Debye (RGD) scattering, T Ray is the transmission resulting from Rayleigh scattering, T GA is the Gaussian absorption on transmission, and T LA is the Lorentzian absorption on transmission.…”

“…It means that T R should be slightly larger than calculated based on Equation (). [ 21 ] When appropriate antireflection film is coated onto the 0.5 and 1 mol% Sm‐doped PMN‐PT ceramics, their transparency will further improve to be larger than 97%. It means that they have already met the transparency requirements for practical devices.…”

“…For the in-line transmission measurements of an ideal transparent ceramic, reflection, scattering, and absorption losses should be considered. The total in-line transmission given by Shachar et al is expressed as below [21] T T T T T T R RGD Ray GA LA…”

An Analytical Model of Light Scattering by Birefringent Polycrystalline Dielectrics Using Perturbation of Maxwell's Equations

“…Figure demonstrates the effect of the large‐size to small‐size transition on the scattering transmission spectrum. For short wavelengths, the scattering coefficient is proportional to $${\lambda ^{ - 2}}$$ (large‐size RGD scattering; sometimes goes under the misnomer “RGD scattering” [ 11,13,15,16 ] ). For longer wavelengths, the scattering coefficient is proportional to $${\lambda ^{ - 4}}$$, which is characteristic of Rayleigh scattering.…”

“…Predicting scattering from the microstructure could be utilized for converting optical design parameters into material/microstructural specifications. In combination with our earlier work, [ 11 ] such predictions could be used, for instance, to design characterization techniques that extract absorption coefficients from in‐line transmission spectra. Characterizing the microstructure using scattering would be invaluable because it would afford a non‐invasive, non‐destructive technique for extracting microstructural information from in‐line transmission measurements (which can take as few as 5 min to collect using commercially available spectrophotometers).…”