Superresolution lensfree microscopy

超分辨率无透镜显微镜显微镜对于研究生物系统，天然材料和人造设备非常重要。传统上，使用可见光的光学显微镜无法分辨小于光波长一半的物体，光波长通常比细菌小，但比病毒大。对超分辨率显微镜的研究使更小的物体可视化，可用于在医学测试中识别病毒，了解细胞的内部生物机制如何运作，量化空气和水中的纳米级污染物，或表征合成的纳米材料，以确保它们按需制造。一种特殊类型的光学显微镜，无透镜显微镜，依赖于计算算法来从相机传感器上记录的阴影图案重建显微图像。它比传统显微镜更紧凑、更具成本效益，并提供更大的视野。该项目的目标是实现超分辨率与无透镜显微镜可视化超小物体，同时保持上述无透镜显微镜的优势。除研究生外，本科生和高中生也参与了该项目，并正在创建一个新的教学模块。无透镜显微镜的分辨率极限取决于多种因素，包括信噪比，相干性和衍射。相干无透镜显微术先前已经实现了衍射极限分辨率，而非相干无透镜显微术（例如，荧光成像）以前已经证明分辨率比衍射极限差几倍。在这个项目中，超分辨率无透镜显微镜是通过将一个纳米结构的掩模定位在一个未知物体的倏逝场中来实现的。该掩模可以编码关于物体的高分辨率信息（以稍后可解码的方式），这些信息通常会由于衍射而丢失。通过系统地扫描掩模的几何参数，研究团队正在生成关于分辨率提升可能范围的知识。噪音的影响正在被量化。比较了不同重建算法的速度和分辨率性能。超分辨掩模几何估计的光学方法正在测试中。这些知识可以为理论模型提供信息，这些理论模型将用于指导未来改进的参数选择，从而通过紧凑便携的设备和快速的计算重建时间实现更好的分辨率。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Title: Superresolution Lensfree MicroscopyMicroscopy is important for studying biological systems, natural materials, and human-made devices. Optical microscopes that use visible light are traditionally incapable of resolving objects smaller than one-half the wavelength of the light, which is a size scale generally smaller than bacteria, but larger than viruses. Research into superresolution microscopy enables visualization of even smaller objects, which can be used to identify viruses in medical testing, learn how the inner biological mechanisms of cells operate, quantify nanoscale pollutants in air and water, or characterize synthesized nanomaterials to ensure that they are being manufactured as desired. A specific type of optical microscopy, lensfree microscopy, relies on computational algorithms to reconstruct microscopic images from shadow patterns recorded on a camera sensor. It is more compact and cost-effective than traditional microscopes and offers a larger field of view. The objective of this project is to achieve superresolution with lensfree microscopes to visualize ultra-small objects while maintaining the aforementioned advantages of lensfree microscopy. In addition to graduate students, undergraduates and high schoolers are involved in the project, and a new teaching module is being created.The resolution limit in lensfree microscopy depends on a variety of factors, including signal-to-noise ratio, coherence, and diffraction. Coherent lensfree microscopy has previously achieved diffraction-limited resolution, while incoherent lensfree microscopy (e.g., fluorescence imaging) has previously demonstrated resolution that is several times worse than the diffraction limit. In this project, superresolution lensfree microscopy is being achieved by positioning a nanostructured mask within the evanescent field of an unknown object. This mask can encode high resolution information (in a way that is later decodable) about the object that would normally be lost due to diffraction. By systematically sweeping geometric parameters of the mask, the research team is generating knowledge of what range of resolution boost is possible. The impact of noise is being quantified. The speed and resolution performance of different reconstruction algorithms are being compared. Optical methods of superresolved mask geometry estimation are being tested. This knowledge can inform theoretical models that will then be used to guide parameter choices for future improvements that can enable better resolution with compact and portable equipment and fast computational reconstruction times.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.