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Updated: Jun 29, 2026
10:21
Evanescent Field Based Photoacoustics: Optical Property Evaluation at Surfaces
Published on: July 26, 2016
Gloss optical elementary representative surface
Pierre Vernhes1, Jean-Francis Bloch, Anne Blayo
1Ecole Française de Papeterie et des Industries Graphiques (EFPG), 461 rue de la papeterie, BP 65, 38402 Saint-Martin d'Hères, France. pierre.vernhes@efpg.inpg.fr
Applied Optics
|October 11, 2008
Summary
Understanding paper surface structure is key for optical properties. This study developed ray-tracing software to determine the optimal scale for roughness measurements, ensuring optically representative results for specular gloss.
Area of Science:
- Materials Science
- Optics
- Surface Metrology
Background:
- Accurate characterization of paper and print optical properties relies heavily on roughness measurements.
- Current understanding lacks clarity on the representative surface area and measurement spacing needed for optical characterization.
- Paper's multiscale nature means roughness parameters derived from 3D surface mapping are sensitive to discretization size and step.
Purpose of the Study:
- To investigate the relationship between surface topography measurement scale and optical properties of paper.
- To develop and validate a ray-tracing model for simulating light reflection on paper surfaces.
- To identify the optically representative magnification for various paper grades to accurately predict specular gloss.
Main Methods:
- Development of novel ray-tracing software based on optical geometry.
- Utilizing a new optical device for measuring paper surface topographies across multiple scales.
- Performing ray-tracing simulations on 3D surface maps and comparing results with experimental scattering indicatrix data obtained via goniometry.
Main Results:
- Ray-tracing simulations successfully modeled light reflection on paper surfaces.
- Comparison between simulated and experimental scattering indicatrices validated the ray-tracing approach.
- A specific magnification range was identified as optically representative for predicting specular gloss across different paper types.
Conclusions:
- Ray tracing is a viable tool for modeling light reflection and understanding paper surface optics.
- The study successfully determined the scale-dependent nature of roughness measurements for optical characterization.
- The findings provide a method to select appropriate measurement parameters for reliable specular gloss assessment in paper and print industries.
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