Aidukas Tomas, Loetgering Lars, Harvey Andrew R
Opt Express. 2022 Jun 20;30(13):22421-22434. doi: 10.1364/OE.458657.
In Fourier ptychography, multiple low resolution images are captured and subsequently combined computationally into a high-resolution, large-field of view micrograph. A theoretical image-formation model based on the assumption of plane-wave illumination from various directions is commonly used, to stitch together the captured information into a high synthetic aperture. The underlying far-field (Fraunhofer) diffraction assumption connects the source, sample, and pupil planes by Fourier transforms. While computationally simple, this assumption neglects phase-curvature due to non-planar illumination from point sources as well as phase-curvature from finite-conjugate microscopes (e.g., using a single-lens for image-formation). We describe a simple, efficient, and accurate extension of Fourier ptychography by embedding the effect of phase-curvature into the underlying forward model. With the improved forward model proposed here, quantitative phase reconstruction is possible even for wide fields-of-views and without the need of image segmentation. Lastly, the proposed method is computationally efficient, requiring only two multiplications: prior and following the reconstruction.
在傅里叶叠层成像术中，会捕获多个低分辨率图像，随后通过计算将它们组合成一个高分辨率、大视场的显微图像。通常会使用一种基于从各个方向进行平面波照明假设的理论成像模型，将捕获的信息拼接在一起，形成一个高合成孔径。潜在的远场（夫琅禾费）衍射假设通过傅里叶变换连接源平面、样品平面和光瞳平面。虽然计算简单，但该假设忽略了点光源非平面照明引起的相位曲率以及有限共轭显微镜（例如，使用单透镜进行成像）产生的相位曲率。我们通过将相位曲率的影响嵌入到基础前向模型中，描述了一种简单、高效且准确的傅里叶叠层成像术扩展方法。利用这里提出的改进前向模型，即使对于宽视场也能够进行定量相位重建，并且无需图像分割。最后，所提出的方法计算效率高，在重建之前和之后仅需要两次乘法运算。
