Scanning force microscopy of coatings and nanostructured surfaces

The capability of scanning force microscopy and subsequent PSD data evaluation for the investigation of functional surface nanostructures is demonstrated. Critical effects emerging from measurements in the nanometer scale are discussed

Light scattering of thin dielectric films

This paper focuses on scattering phenomena resulting from isotropic microroughness as well as from correlated volume inhomogenities in dielectric thin films. Even if volume effects, as a rule, contribute much less to the scattering losses of optical coatings than microroughness does, benefits can be derived from examining volume scattering dur to the inherent information about film morphology

Roughness analysis of optical films and substrates by atomic force microscopy

From atomic force microscopy (AFM) topographic data, the power spectral densities (PSDs) of substrate and film surfaces were calculated over extended bandwidths. The results were successfully compared with PSDs obtained from angle-resolved scattering (ARS) measurements, while considering the overlapping spectral frequency range of both methods. The PSD curves obtained by AFM also proved to be a suitable tool for investigating the influence of the substrate on the surface topography of thin film coatings. A correlation factor quantifying the relation between the substrate and film PSDs suggest as a measure of substrate replication effects after thin film deposition

Light Scattering Techniques for the Inspection of Microcomponents and Structures

Ever-increasing surface quality requirements call for advanced, highly sensitive as well as noncontact and area-covering inspection tools. Light-scattering techniques have become widely recognized to fulfil these demands. This chapter describes how a large variety of surface quality-relevant effects such as micro- and nanostructures, roughness, defects, and coating inhomogeneities can be advantageously inspected through light-scattering measurements. Following a brief outline of the theoretical basics on roughness-induced light scattering, main scattering measurement principles suitable for a wide range of applications, extending from supersmooth optical surfaces to microcomponent and microstructure components, are described. Standardization for total and angle-resolved light-scattering measurements, as well as general aspects and examples on how to combine light-scattering techniques with profilometric methods, are discussed

Roughness evolution and scatter losses of multilayers for 193 nm

The roughness and angle resolved scattering of all-fluoride highly reflective mirrors for 193 nm deposited onto differently polished substrates were measured and analyzed. The influence of interface roughness and optical film thicknesson the scatter losses is discussed

UV-VIS-NIR scatter measurement methods for ultra precision surfaces and coatings

The capabilities of our optimized angle resolved and total light scattering measurement systems in the ultraviolet to near-infrared spectral ranges are described and examples of investigations on multilayer gratings and diamond turned optics given. ©2007 Optical Society of Americ

AFM helps engineer low-scatter thin films

The paper dicusses several aspects of thin-film and substrate surface microstructures as they relate to scatter losses. Surface roughness and scatter are related through Power Spectral Density analysis of AFM roughness data. A practical way is shown how to predict scatter effects when PSD curves are known

Position detection with hyperacuity using artificial compound eyes

Inspired by the natural phenomenon of hyperacuity, a novel approach has been analyzed that allows to access highly accurate information with an artificial apposition compound eye despite the number of image pixels is small. This is achieved by oversampling of the object space due to overlapping fields-of-view of adjacent optical channels. The first approach uses the knowledge about the impulse response function derived by linear system theory to calculate the position of objects like point sources and edges from the measured optical powers in adjacent channels. Therefore, the implementation of a precise position detection with an accuracy increase of up to 50 times compared to the conventional image resolution is demonstrated. The second approach that is presented, works in a more general way because it is independent of the exact imaging model. With the help of the latter, the accuracy of the position detection of an edge was increased by a reproducible factor of 25. As presented here, the second approach also enables the measurement of a width with sub-pixel accuracy