Light scatter technique for application in optics, nanotechnology and engineering
Driven by the ever increasing requirements for optical surfaces, components and systems light increasing attention is paid to scattering techniques for the analysis of optical losses, roughness, and defects of coated and uncoated components. Furthermore, angle- and polarization dependent transmittance and reflectance measurements can be performed. The field of application of such measurement extends from UV photolithography, communication technology, nanostructured surfaces, camera systems etc. to rough engineering surfaces and appearance evaluation of esthetically demanding surfaces. To meet these requirements, several arrangements have been developed at the Fraunhofer IOF Jena to measure the total and angle resolved light scattering (TS, ARS, respectively) and AOI (Angle Of Incidence) - dependent reflectance and transmittance in the VUV (Vacuum Ultra Violet) to IR (Infrared) spectral region. Extremely high sensitivities down to 0.05 ppm have been achieved for TS measu rements and a dynamic range of 12 orders of magnitude for ARS. Fully automatic operation enables rapid and robust investigation of extended sample areas. TS measurements are carried out according to the international standard ISO 13696. Besides the measurement techniques, software tools were developed on the basis of scattering theories, which enable a sophisticated evaluation of the measured data for both uncoated and coated surfaces.