Development of dispersion models and fitting algorithm for multi-wavelength ellipsometry



M.Sc. Chia-Wei Chen




August 2020

The Fraunhofer Institute of Optronics, System Technologies and Image Exploitation IOSB is the largest European research institution in the field of image acquisition, processing and analysis. In the Visual Inspection Systems (SPR) department, new approaches to automatic image evaluation and machine vision are pursued and implemented in systems for solving industrial visual inspection tasks.


Ellipsometry is a widely used optical method for the characterization of materials and thin films. It provides high precision, sensitive and non-destructive measurements. However, conventional ellipsometry is only suitable for samples with flat or nearly flat surfaces. At Fraunhofer IOSB, a new concept of retroreflex ellipsometry has been developed to overcome the restriction. For more details, please refer to the links below.


  • Review of recent literature for dispersion models in ellipsometry
  • Implement dispersion models, e.g., Cauchy, Lorentz and Drude models
  • Develop fitting tools for multi-wavelength ellipsometry
  • Validate and analyze the experimental results


Students with a background in physics, computer science, mathematics, or other engineering majors. Prior knowledge in fundamental optics and programming is welcome. Strong analytical and problem-solving skills, excellent communication, organizational and interpersonal skills, and ability to work independently are expected.


M. Sc. Chia-Wei Chen 

Fraunhofer IOSB Visual Inspection Systems SPR

Fraunhoferstraße 1, 76131 Karlsruhe


Tel.: 0721 6091-590