(Peer-Reviewed) Robust far-field imaging by spatial coherence engineering
Yonglei Liu ¹ ², Yahong Chen 陈亚红 ³, Fei Wang 王飞 ³, Yangjian Cai 蔡阳健 ¹ ² ³, Chunhao Liang 梁春豪 ¹ ², Olga Korotkova ⁴
¹ Shandong Provincial Engineering and Technical Center of Light Manipulations & Shandong Provincial Key Laboratory of Optics and Photonic Device, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China
中国 济南 山东师范大学物理与电子科学学院 光场调控及应用中心 山东省光学与光子器件技术重点实验室
² Collaborative Innovation Center of Light Manipulations and Applications, Shandong Normal University, Jinan 250358, China
中国 济南 山东师范大学 光场调控及应用协同创新中心
³ School of Physical Science and Technology, Soochow University, Suzhou 215006, China
中国 苏州 苏州大学物理科学与技术学院
⁴ Department of Physics, University of Miami, Coral Gables, Florida 33146, USA
The degree of coherence (DOC) function that characterizes the second-order correlations at any two points in a light field is shown to provide a new degree of freedom for carrying information. As a rule, the DOC varies along the beam propagation path, preventing from the efficient information recovery.
In this paper, we report that when a partially coherent beam carrying a cross phase propagates in free space, in a paraxial optical system or in a turbulent medium, the modulus of the far-field (focal plane) DOC acquires the same value as it has in the source plane. This unique propagation feature is employed in a novel protocol for far-field imaging via the DOC, applicable to transmission in both free-space and turbulence.
The advantages of the proposed approach are the confidentiality and resistance to turbulence, as well as the weaker requirement for the beam alignment accuracy. We demonstrate the feasibility and the robustness of the far-field imaging via the DOC in the turbulent media through both the experiment and the numerical simulations. Our findings have potential applications in optical imaging and remote sensing in natural environments, in the presence of optical turbulence.