Tian Zhanquan, Li Lina, Ma Jianshe, Cao Liangcai, Su Ping
Opt Lett. 2024 Jun 15;49(12):3532-3535. doi: 10.1364/OL.527533.
In lensless imaging using a Fresnel zone aperture (FZA), it is generally believed that the resolution is limited by the outermost ring breadth of the FZA. The limitation has the potential to be broken according to the multi-order property of binary FZAs. In this Letter, we propose to use a high-order component of the FZA as the point spread function (PSF) to develop a high-order transfer function backpropagation (HBP) algorithm to enhance the resolution. The proportion of high-order diffraction energy is low, leading to severe defocus noise in the reconstructed image. To address this issue, we propose a Compound FZA (CFZA), which merges two partial FZAs operating at different orders as the mask to strike a balance between the noise and resolution. Experimental results verify that the CFZA-based camera has a resolution that is double that of a traditional FZA-based camera with an identical outer ring breadth and can be reconstructed with high quality by a single HBP without calibration. Our method offers a cost-effective solution for achieving high-resolution imaging, expanding the potential applications of FZA-based lensless imaging in a variety of areas.
在使用菲涅耳区孔径（FZA）的无透镜成像中，人们普遍认为分辨率受FZA最外环宽度的限制。根据二元FZA的多阶特性，这种限制有可能被打破。在本信函中，我们提议使用FZA的高阶分量作为点扩散函数（PSF），以开发一种高阶传递函数反向传播（HBP）算法来提高分辨率。高阶衍射能量的比例较低，导致重建图像中出现严重的散焦噪声。为了解决这个问题，我们提出了一种复合FZA（CFZA），它将两个不同阶次的部分FZA合并作为掩模，以在噪声和分辨率之间取得平衡。实验结果验证，基于CFZA的相机在具有相同外环宽度的情况下，分辨率是传统基于FZA的相机的两倍，并且可以通过单次HBP高质量重建而无需校准。我们的方法为实现高分辨率成像提供了一种经济高效的解决方案，扩展了基于FZA 的无透镜成像在各种领域的潜在应用。
