COMPUTER-AIDED APPROACH TO SLIT PHASE-CONTRAST MICROSCOPY

Properties and new possible applications of the slit phase contrast te chnique are presented. They are tested by an advanced computer simulat ion program. A digital 2-D spatial filtering process is performed. A c omposition of phase objects (e.g., circles, rectangles, gratings, fibe rs) is transformed into its Fourier form, multiplied by the transmitta nce of the phase strip, and finally retransformed. According to the si mulation results, several soot filters are prepared and applied to a m odified commercial microscope. The experiments mainly involve biologic al specimens. Special attention is given to measurements of the refrac tive index profile of the optical fibers. A detailed theoretical backg round is presented and the results of additional computer simulation b ased on the operation of convolution are discussed.