Unidirectional imaging with partially coherent light
<|reference_start|>Unidirectional imaging with partially coherent light: Unidirectional imagers form images of input objects only in one direction, e.g., from field-of-view (FOV) A to FOV B, while blocking the image formation in the reverse direction, from FOV B to FOV A. Here, we report unidirectional imaging under spatially partially coherent light and demonstrate high-quality imaging only in the forward direction (A->B) with high power efficiency while distorting the image formation in the backward direction (B->A) along with low power efficiency. Our reciprocal design features a set of spatially engineered linear diffractive layers that are statistically optimized for partially coherent illumination with a given phase correlation length. Our analyses reveal that when illuminated by a partially coherent beam with a correlation length of ~1.5 w or larger, where w is the wavelength of light, diffractive unidirectional imagers achieve robust performance, exhibiting asymmetric imaging performance between the forward and backward directions - as desired. A partially coherent unidirectional imager designed with a smaller correlation length of less than 1.5 w still supports unidirectional image transmission, but with a reduced figure of merit. These partially coherent diffractive unidirectional imagers are compact (axially spanning less than 75 w), polarization-independent, and compatible with various types of illumination sources, making them well-suited for applications in asymmetric visual information processing and communication.<|reference_end|>
@article{ma2024unidirectional,
    title={Unidirectional imaging with partially coherent light},
    author={Guangdong Ma, Che-Yung Shen, Jingxi Li, Luzhe Huang, Cagatay Isil,
  Fazil Onuralp Ardic, Xilin Yang, Yuhang Li, Yuntian Wang, Md Sadman Sakib
  Rahman, Aydogan Ozcan},
    journal={Advanced Photonics Nexus (2024)},
    year={2024},
    doi={10.1117/1.APN.3.6.066008},
    archivePrefix={arXiv},
    eprint={2408.05449},
    primaryClass={physics.optics cs.CV physics.app-ph}
}