P. Kadkhoda
W. Sakiew
S. Günster
D. Ristau

Fast total scattering facility for 2D inspection of optical and functional surfaces

SPIE Optical Metrology: Optical Measurement Systems for Industrial Inspection
15.-18. Juni
München
2009
Type: Konferenzbeitrag
Abstract
Optical scatter measurements are the basis for efficient methods in the quality management of optical components in all production steps. Especially, the Total Scattering (TS) of an optical surface can be evaluated in respect of the roughness and the state of cleanliness. In many applications defects on the surface or the imperfections in the bulk of the components are of major interest and have to be controlled systematically. In this paper a fast TS measurement procedure is presented for flat components, which can map a surface completely in the timescale of few ten to hundred seconds. The mapping covers the entire test area with spatial steps of less than one micron. The set-up can be adapted to wavelengths from the UV- to the IR- spectral ranges. The present study is dedicated to the technical specifications, problems during implementation and the resolution limits of the Fast TS set-up. TS measurements on samples with defined micro structures are employed to demonstrate the spatial resolution. Results of TS measurements in forward and backward direction will be presented for selected samples with defined particle distribution and sizes.