Guo Kaikai, Zhang Zibang, Jiang Shaowei, Liao Jun, Zhong Jingang, Eldar Yonina C, Zheng Guoan
Biomedical Engineering, University of Connecticut, Storrs, CT 06269, USA.
Department of Optoelectronic Engineering, Jinan University, Guangzhou 510632, China.
Biomed Opt Express. 2017 Dec 19;9(1):260-275. doi: 10.1364/BOE.9.000260. eCollection 2018 Jan 1.
Fluorescence imaging through a turbid layer holds great promise for various biophotonics applications. Conventional wavefront shaping techniques aim to create and scan a focus spot through the turbid layer. Finding the correct input wavefront without direct access to the target plane remains a critical challenge. In this paper, we explore a new strategy for imaging through turbid layer with a large field of view. In our setup, a fluorescence sample is sandwiched between two turbid layers. Instead of generating one focus spot via wavefront shaping, we use an unshaped beam to illuminate the turbid layer and generate an unknown speckle pattern at the target plane over a wide field of view. By tilting the input wavefront, we raster scan the unknown speckle pattern via the memory effect and capture the corresponding low-resolution fluorescence images through the turbid layer. Different from the wavefront-shaping-based single-spot scanning, the proposed approach employs many spots (i.e., speckles) in parallel for extending the field of view. Based on all captured images, we jointly recover the fluorescence object, the unknown optical transfer function of the turbid layer, the translated step size, and the unknown speckle pattern. Without direct access to the object plane or knowledge of the turbid layer, we demonstrate a 13-fold resolution gain through the turbid layer using the reported strategy. We also demonstrate the use of this technique to improve the resolution of a low numerical aperture objective lens allowing to obtain both large field of view and high resolution at the same time. The reported method provides insight for developing new fluorescence imaging platforms and may find applications in deep-tissue imaging.
通过浑浊层进行荧光成像在各种生物光子学应用中具有巨大潜力。传统的波前整形技术旨在通过浑浊层创建并扫描一个焦点光斑。在无法直接访问目标平面的情况下找到正确的输入波前仍然是一项关键挑战。在本文中，我们探索了一种用于大视场浑浊层成像的新策略。在我们的设置中，一个荧光样本夹在两个浑浊层之间。我们不是通过波前整形生成一个焦点光斑，而是使用一个未整形的光束照射浑浊层，并在目标平面的宽视场上生成一个未知的散斑图案。通过倾斜输入波前，我们利用记忆效应光栅扫描未知散斑图案，并通过浑浊层捕获相应的低分辨率荧光图像。与基于波前整形的单点扫描不同，所提出的方法并行使用多个点（即散斑）来扩展视场。基于所有捕获的图像，我们联合恢复荧光物体、浑浊层的未知光学传递函数、平移步长和未知散斑图案。在无法直接访问物平面或不了解浑浊层的情况下，我们使用所报道的策略展示了通过浑浊层实现13倍的分辨率提升。我们还展示了使用该技术来提高低数值孔径物镜的分辨率，从而能够同时获得大视场和高分辨率。所报道的方法为开发新的荧光成像平台提供了思路，并且可能在深层组织成像中找到应用。
