Specific properties of slit phase-contrast imaging

摘要

Properties and new possible applications of the slit phase contrast (SPhC) technique are presented. They have been tested by the use of an advanced computer simulation program, performing a digital 2D spatial filtering process. A composition of phase objects (e.g., circles, rectangles, gratings, fibers) is transformed into its Fourier form, then multiplied by the transmittance of the phase strip and finally retransformed. Several soot filters have been prepared and applied to a modified, commercial microscope according to the simulation results. The experiments have involved mainly biological specimens. Special attention has been given to measurements of the refractive index profile of the optical fibers. A detailed theoretical background has been presented and results of additional computer simulation based on the operation of convolution have been discussed.