Multi-planar low-coherence diffraction imaging

Coherent diffraction imaging (CDI) is a popular methodology for quantitative phase restoration and wavefront measurements from several desired intensity measurements that have wide applications ranging from wavefront sensing in adaptive optics to optical imaging. To overcome the problem of image quality degradation caused by the high coherence of the light source, a multi-planar low-coherent diffraction imaging (LCDI) method under low-coherence light sources was proposed and verified by measuring an U.S. Air Force (USAF) resolution test target and a nine-letter element. Negative lenses with different focal lengths were designed as filters in the image-relay system to capture multi-planar diffraction patterns at a single recording plane, and a multi-planar LCDI algorithm was used to reconstruct the test sample using a set of intensity images. Its feasibility was demonstrated experimentally using a super-radiation light-emitting diode. Considering its compact setup, easy realization, high speed, and easy operation in phase recovery, this method is effective for rapidly detecting phase and wavefront measurements with high accuracy and resolution.