Study on the Generation and Elimination of Conjugate Image in Coherent Different Imaging

Conjugate image is an inherent problem of coherent diffraction imaging (CDI) and direct analysis and research on them have long been incomplete. By writing diffraction intensities into linear equation set, it was demonstrated that the fundamental mathematical reason for the generation of conjugate image lies on the real-value coefficients of these linear equations, and then the conjugate image could be eliminated by adopting optical alignments that can lead to complex–value coefficients. While theoretical analysis was proposed its feasibility was verified both numerically and experimentally. The study provides new insights into the physical mechanism of CDI and new strategies to improve the image quality of other phase retrieval techniques.