1. Unidirectional imaging with partially coherent light
- Author
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Ma, Guangdong, Shen, Che-Yung, Li, Jingxi, Huang, Luzhe, Isil, Cagatay, Ardic, Fazil Onuralp, Yang, Xilin, Li, Yuhang, Wang, Yuntian, Rahman, Md Sadman Sakib, and Ozcan, Aydogan
- Subjects
Physics - Optics ,Computer Science - Computer Vision and Pattern Recognition ,Physics - Applied Physics - Abstract
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., Comment: 25 Pages, 8 Figures
- Published
- 2024