Phase Contrast Imaging Systems for Enhancing Linearity and Suppressing Background-Bleaching Effects,

摘要

Phase contrasts objects,which retard the wavefronts of incident light but leave the intensity unaltered,would remain invisible except for Schlieren, Zernike or similar viewing techniques. Most techniques however possess little or no capability for linear operation. The present study investigates a new scheme which extends the linear operating range by about a factor of ten over previous techniques. After reviewing phase contrast imaging theories,the study analyzes the new scheme,discusses various alternative implementations,estimates the effects of fabrication errors,and assesses the opportunities for trading off linearity against a reduction in background-bleaching effects. (Author)