P. KETOLAINEN, R. SILVENNOINEN, K.-E. PEIPONEN and P. RAERINNE

Väisälä Laboratory, Department of Physics, University of Joensuu, P.O. Box 111, FIN-80101 Joensuu, Finiand

(Accepted August 4, 1994)

The surface quality of alkali halide crystals to be used in spectroscopy and as laser components has been sensed using a computer-generated hologram together with digital image processing. FFT and two-dimensional cross-correlation analyses. Surfaces cleaved only or finished to various extents are considered as examples.

Key words : optical sensing, surface quality, surface roughness, computer-generated hologram, image processing, fast Fourier transform, cross-correlation analysis