Bingyang Wang, Huixiang Lin, Fucai Zhang，“Coherent diffraction imaging of layered samples via unknown illumination diversity”，Optics and Lasers in Engineering 195, 109315（2025）

【原文】

Coherent diffraction imaging of layered samples via unknown illumination diversity

ABSTRACT

Techniques that can reveal internal structures of layered or thick samples are crucial in materials science and engineering. Current coherent diffraction imaging (CDI) methods still face challenges when used with thick samples, such as demanding a large volume of data, high experimental complexities, and limited performance. This paper proposes a CDI method suitable for layered samples by exploiting structured illuminations. Numerical simulations have shown that this technology can effectively reconstruct samples with up to 10 layers. Meanwhile, visible-light optical experiments have also successfully reconstructed the distribution of 3-layer samples. Importantly, the unknown illumination probes can be simultaneously retrieved along with the sample, saving the need for precise system and illumination calibration. The method has a simple setup and potentially offers an alternative means for structure determination of thick samples. The ability to work with variable, unknown illumination could be desirable for beam-forming devices calibration at synchrotron facilities when the beam instability is inevitable.